SDO Teams Meeting
25-28 March 2008
Napa Valley Marriott
Napa, California U.S.A.
Purposes of the Meeting
With the launch of the Solar Dynamics Observatory, NASA's first LWS mission, only
about one year away, the AIA, EVE, and HMI instrument teams of SDO are planning a
4-day joint meeting of the science teams at the Napa Valley Marriott from Tuesday,
March 25 through Friday, March 28, 2008.
The meeting will bring together the co-investigator teams from the entire SDO mission
and others beyond those core teams who are committed to actively participating in the
science investigations.
This workshop provides an opportunity to help shape the infrastructure that enables
scientists to easily find, access, and analyze data of interest in the enormous SDO
archives.
Strong emphasis will be placed on planning those activities that need to be completed
before launch and during the first two years of the mission.
The agenda will feature a series of (often parallel) scientific and technical working
groups to discuss how the SDO data is best accessed, distributed, and analyzed, and what
tools are needed to best stimulate scientific discoveries.
Posters are encouraged for science and techniques relevant to the goals of SDO.
Participation
The meeting is important for all co-I's and science team members. All EVE, AIA, and
HMI science team members are invited and expected to attend. We also welcome all
other members of the community who plan to significantly contribute to the science of
SDO.
SDO Teams Meeting
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Tuesday @ 8:30 a.m.
SDO Project Status & Plans
Leader: Dean Pesnell
The opening session of the meeting will feature status reports from the SDO instrument
teams the the SDO project.
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8:30 SDO Project Status, Dean Pesnell
8:40 LWS Program Status, Lika Guhathakurta
8:50 SDO Program Update, Alex Pevtsov
9:00 Q&A, Moderated by Dean Pesnell
9:15 EVE Investigation Status, Tom Woods
9:30 HMI Investigation Status, Phil Scherrer
9:45 AIA Investigation Status, Alan Title
Tuesday @ 10:30 a.m.
Science & EPO Plenary
Leader: A. Kosovichev
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10:30 Presentation of SDO Project E/PO Plans, Emilie Drobnes
10:45 Looking to the Future of Space Weather Specification and Geospace
Forecasting, Dan BakerLooking to the Future of Space Weather
Specification and Geospace Forecasting
Daniel N. Baker
Laboratory for Atmospheric and Space Physics, University of Colorado,
Boulder, CO
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Recent international space science programs have made a concerted effort to
study activity on the Sun, the propagation of energy bursts from the Sun to nearEarth space, energy coupling into the magnetosphere, and its redistribution and
deposition in the upper and middle atmosphere. Extreme solar, geomagnetic and
solar wind conditions can be observed by a large international array of satellites
and ground-based sensors. We briefly discuss the types of space weather-related
problems that have been identified in recent years and consider examples of space
weather-induced spacecraft (and ground-based) anomalies and failures that affect
both civilian and military systems. In this context, we discuss near-term plans to
consolidate and integrate results from these many international programs and
campaigns. An important component of this community effort is to propose
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technical and operational solutions to space weather problems that can be
achieved in the next 5-10 years. This talk will focus on new scientific
understanding that is needed for successful space weather programs and will
describe actions that can help assure a good future integrated space weather
program. We will particularly try to anticipate what observations and models will
be needed within the geospace domain to enable successful forecasting
capabilities.
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11:25
Sources of Solar Irradiance Variability, Harry Warren
NRL
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The physical conditions in the Earth's upper atmosphere, such as the particle
density or the state of ionization, are largely determined by the magnitude and
variability of the solar irradiance. As our presence in space has expanded, so has
our need for timely and accurate information on the upper atmosphere.
Atmospheric density measurements, for example, are needed to forecast satellite
drag and predict the motion of space debris. Information on the ionosphere is
needed to assess the accuracy of GPS measurements. One of the primary goals of
the SDO mission is to understand the sources of irradiance variability using
combined observations from EVE, AIA, and HMI. In this talk we will discuss the
relationship between photospheric magnetic fields, solar features in the
chromosphere, transition region, and corona, and changes in the solar radiative
output at UV, EUV, and soft X-ray wavelengths. At the most basic level, changes
in the solar irradiance can be understood in terms of changes in the total unsigned
magnetic flux. Understanding irradiance variability in detail, however, requires
determining how various solar features contribute to the radiative output of the
Sun.
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11:50 Recent Progress Toward Incorporating Observational Data into
Theoretical Models of the Sun's Magnetic Field, Bill Abbett
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In recent years, significant progress has been made in our ability to model the
Sun's magnetic field over a wide range of spatial and temporal scales, and over
many physically-distinct regions of the solar atmosphere and interior. A wide
range of numerical models of varying complexity are available to the
Heliophysics research community, including magnetostatic models such as
potential field and force-free extrapolations, and dynamic models such as
radiative hydrodynamic solvers, and MHD codes. In addition, the quality and
quantity of observational data continues to improve. These efforts do not proceed
independently: synthetic data is routinely used to validate helioseismic and
velocity inversion techniques, and observational data is used to validate, initiate,
and in some cases drive numerical models. With an eye toward motivating
discussion on how best the SDO data can be used to facilitate these investigations,
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I will briefly review recent progress toward assimilating data into models, and
will describe some the theoretical challenges inherent to this process.
Tuesday @ 1:30 p.m.
Magnetic Field and Coronal Models I: Synoptic Maps
and Potential Field Models
Leaders: Bill Abbett & Todd Hoeksema
In this opening session of the Magnetic Field/Coronal Modeling thread, we will begin by
introducing the goals and objectives of the upcoming sessions from the perspective of the
three teams HMI, AIA, and EVE. Once we have laid the groundwork for the upcoming
discussions, we will then move on to a detailed discussion of how best to implement
some of the more traditional models and data products into the software pipeline. In
particular, we will focus on the generation of synoptic maps, farside maps, and
PFSS/CSSS models.
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1:30 - Introduction (Hoeksema)
1:35 - Instrument Team Needs & Plans
o HMI
o AIA
o EVE
2:00 - Synoptic Maps (Various)
o Synchronic & Synoptic Maps
o Synoptic Frames
o Far Side Simultations
2:40 - Potential and Current Sheet Models (Various)
Tuesday @ 1:30 p.m.
Thermal Structure: Recent Observations
Leader: Harry Warren
New observations from STEREO, XRT, and EIS have greatly expanded our ability to
observe the thermal structure of the solar corona. These observations are likely to have
important implications for the analysis of AIA observations.
Brief Talks on Recent Results (50 minutes)
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STEREO Observations of 1 MK Loops in 3D - Aschwanden (12 min)
EIS Observations of Overdense 1 MK Loops - Warren (12 min)
EIS Observations of Hot Lines - Patsourakos (12 min)
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XRT Observations of Active Regions - Reeves (12 min)
Discussion (40 minutes)
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What are the main observational questions that need to be pursued with AIA and
how can they be achieved? For example, how can we best determine the physical
parameters (e.g., density, temperature, pressure, and filling factor) of loops as a
function of time with AIA? Will we need other observations (e.g., EIS density
diagnostics or different vantage points from STEREO)? Are special codes needed
(e.g., loop identification codes)?
Tuesday @ 1:30 p.m.
Helioseismology 1: HMI Initial Science Goals and
Targets
Leaders: Juri Toomre & Sasha Kosovichev
Agenda (90 min)
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Large-scale and global MHD dynamics - Juri Toomre (15 min)
Solar Magnetism and Dynamo - Jan Stenflo (15 min)
Emerging Flux and Sunspots - Valentin Martinez Pillet (15 min)
Links to coronal activity; flare and CME initiation - Brian Welsch (15 min)
Solar shape and irradiance sources - Jeff Kuhn (15 min)
General discussion (15 min)
Tuesday @ 1:30 p.m.
Education & Public Outreach
Leader: Emilie Drobnes & Deborah Scherrer
How do we make SDO memorable to the media and the public eye?
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Sun in 3D = STEREO
Astronauts and pretty pictures = Hubble
Moon = LRO
? = SDO
We need your help to fill in the blank!
During this break-out session we will brain storm possible media messages for SDO.
These exciting and attention grabbing messages will become synonymous with our
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mission and help us reach out to the media and the public. This will allow us to not only
share our excitement for the science being performed using SDO but help share its
importance to our community and to our daily lives. We will also hold discussions on the
mechanisms for getting our messages and press releases out and how best to take
advantage of any and all opportunities to spread the word.
Tuesday @ 3:30 p.m.
Grand Ballroom: Cabernet & Zinfandel
Vector Field Production, HMI vs MDI intercalibration
Session Leader: Yang Liu
Vector B (3:30-5:00)
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3:30 Intro. (Liu)
3:31 Update: Observing plan (J. Schou/J. Borrero)
3:41 Update: Calibration (J. Schou)
3:51 Intercalibration Discussion
4:01 Update: Inversion Technique (J. Borrero)
4:11 Update: 180-degree Disambiguation (TBD)
4:21 Overview: Data Processing and Products with SOLIS (C. Henney)
4:31 Summary of HMI Vector Field Products (T. Hoeksema)
4:36 Community discussion
HMI plans to provide vector field data in four categories: quick-look, standard, ondemand and on-request.
Basically, quick-look data products are mostly used for helping operating instruments and
predicting space weather. Standard data products are served as monitor and reference to
meet basic research needs.
On-demand data products are completed for a small fraction of data when interesting
things happen or whenever requested. It is expected that this kind of data products will
serve most research purposes.
On-request data products are completed when system resources allowed. The discussion
is mainly focused on defining the four kinds of products.
Possible topics for discussion
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1. Quick-look data products: Which products are needed for these purposes?
Whatresolution and cadence of data are needed?
2. Requirements on the other three kinds of data products.
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3. Since changes of the horizontal field could occur in fairly short time-scale, any
strategies to make synoptic maps of vector magnetic field physically meaningful?
4. Plans for intercalibration of HMI line-of-sight fields with other instruments
1. Given the performance of these data-processing codes, what are the best cadence
and resolution of the data production that fit both data processing capability and
research goal?
2. Given the difference of the processing and requirement of the active regions and
quiet Sun, what is the best strategy to process the full disk data?
3. What is the best way to present full disk vector field maps?
4. How to produce synoptic maps of vector magnetic field, and what kind of maps
makes physics meaningful and technique doable?
Tuesday @ 3:30 p.m.
Thermal Structure: Theory
Leader: Harry Warren
This will be a session on the forward modeling of active region emission.
* Brief Talks on the Current status of Forward Modeling (30-45 minutes total)
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MHD modeling, Zoran Mikic
Hydrodynamic Modeling, Robert Walsh
Hydrostatic Modeling, Harry Warren
* Discussion (60-45 minutes total)
We will address several lines of questioning during the discussion:
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When will we be able to model the field, add atmospheres, compute emissions,
and compare with observations?
Is that likely to succeed in the coming few years as a routine procedure?
Will it stay a research-grade and time-consuming thing for years to come?
If we succeed, how do we go about learning from that?
We will also consider the various inputs to this modeling (such as magnetic field
extrapolations or the instrumental temperature response functions) and consider if the
MHD and hydrodynamic modeling has any special needs that need to be addressed
before the data pipelines are completed. Finally, we will also discuss the status of various
MHD and hydrodynamic codes.
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Tuesday @ 3:30 p.m.
Local HS 2: Techniques & Comparisons, Simulations &
Validations
Leaders: Deborah Haber & Tom Duvall (Part 1), Bob Stein & Konstantin
Parchevsky (Part 2)
Part 1: Techniques and Intercomparison (45 minutes)
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1. Systematic errors, Deborah Haber
2. Random error estimates - time-distance, Sebastien Couvidat
3. MDI ring diagram frequency variations, Rachel Howe)
4. Comparison of ring diagram and tine-distance results, Brad Hindman
5. Comparison of MDI, GONG with HMI, Tom Duvall
Part 2: Numerical Simulations and Validation of Local Helioseismology
(45 minutes)
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1. Realistic Non linear simulations
o Supergranulation Scale Solar Surface Convection Simulations, (8 min)
Dali Georgobiani
o Realistic numerical simulations of solar magneto-convection, (8 min)
Laetitia Jacoutot
2. Linear Wave Modeling
o Far Side Modeling (TBC), (8 min) Thomas Hartlep
o MHD simulations (TBC), (8 min) Shravan Hanasoge
3. General Discussion, Konstantin Parchevski
o What data are already available?
o What is being planned to be done?
o List of standard tests.
Tuesday @ 5:30 p.m.
Poster Session 1
Session Leader: Todd Hoeksema
This poster session will include a JSOC Demo and focus on Poster Group 1: SDO
Science Topics
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Wednesday @ 8:30 a.m.
Science Plenary + JSOC / Data Handling / Informatics
Leader: Phil Scherrer
8:30 Validating Time-Distance Helioseismology Results by Use of Numerical
Simulations , Junwei Zhao, et al.
Stanford University
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Authors: Junwei Zhao1, Alexander G. Kosovichev1, Robert F. Stein2, Dali
Georgobiani2, Ake Nordlund3, Thomas Hartlep4, and Nagi N. Mansour4
o 1 W.W.Hansen Experimental Physics Laboratory, Stanford University,
Stanford, CA94305-4085
o 2 Department of Physics and Astronomy, Michigan State University, East
Lansing, MI48824
o 3 Niels Bohr Institute, Copenhagen University, DK-2100 Copenhagen,
Denmark
o 4 NASA Ames Research Center, Mailstop 230-2, Moffett Field, CA94035
Because helioseismology is to derive solar properties that cannot be directly
observed, to examine helioseismology techniques on numerically simulated data
is essentially an effective way to validate these techniques. By use of realistic
numerical simulation of solar convections in small scales, i.e., 96Mm in
horizontal dimension and 20 Mm in vertical dimension, we have demonstrated
that time-distance can satisfactorily invert flow fields up to 8 Mm or so into the
interior. By use of numerical simulation of solar acoustic wavefields in global
scales, we have validated the time-distance far-side imaging technique. We also
demonstrate that with the help of numerical simulations, we are able to image
acoustic structures in the solar tachocline area, a crucial area for solar dynamo
operations.
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9:00
Magnetic Fields on Multiple Scales , Sami Solanki
MPI
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The part of the Sun's magnetic field accessible to observations is structured on a
large variety of scales in space as well as in time. In space they reach from the
highest spatial resolution currently achievable to nearly the entire solar surface.
Timescales of magnetic field variation range from minutes to millenia. After a
description of the current knowledge of magnetic field structuring on multiple
scales some of the physical processes leading to such a structure are introduced.
10:00 The SDO Joint Science Operations Center, Phil Scherrer
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Wednesday @ 10:30 a.m.
SDO Knowledge Base
Leader: Karel Schrijver
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10:30 CCMC Capabilities and SDO, Peter MacNiece
10:45 SDO Knowledge Base - Introduction, Karel Schrijver
By about the end of 2008, SDO will give us over 2TB of data per day. That is too much
for almost all of us to retrieve, store, or review on a routine basis. Finding data of interest
within the vast archive of SDO data therefore requires a largely automated system to
identify events, and an efficient system to find and retrieve the metadata on these events
and, ultimately, link to the observations themselves.
As you hopefully know, we are developing a meta-data knowledge base
(http://www.lmsal.com/helio-informatics/hpkb/) that contains information that describes
what happened on the Sun. During the SDO teams meeting, we will demonstrate the
developing system, and discuss with you, the user community, how the system should
function, how it should present its findings in response to your queries, and what kinds of
'events' it should contain. And then, of course, we shall have to discuss which of the
aspects that we would like to have are actually affordable and implementable within the
coming year, and how we make optimal use with work done within the project and in the
community.
Specifically:
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In the morning of Wednesday, March 26, we will present our thoughts on the
system (including how our initial system focused on the Sun can grow into a
broad-reaching Heliophysics system and how it complements the Virtual
Observatories), demonstrate its first incarnation, discuss how features and events
may be found by the analysis of the data flowing into the archive, and start a
discussion on the fundamentals of the system.
Wednesday @ 2:30 p.m.
Knowledge Base Tools - Browse, Search & Output
Leader: K. Schrijver
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Visualization tools
Interfacing with the knowledgebase
Output: options, layout
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Wednesday @ 2:30 p.m.
Space Weather - Plasmas
Leader: Frank Eparvier
This Session will focus on solar-driven particles and fields impacts on the geospace
environment with the following guiding questions:
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What are the plasma forecasting/nowcasting needs of operational community?
What's missing that SDO can provide?
What tools need to be developed for SDO data to be used for space weather?
Tentative agenda (90 minutes total):
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Introduction - Eparvier (5 min)
Currently Planned AIA SWx Products - (10 min)
Currently Planned HMI SWx Products - (10 min)
Potential EVE Plasma-related SWx Products - Eparvier (5 min)
The NOAA/SWPC Perspective - Viereck/Onsager/Biesecker (10 min)
The CCMC Perspective - Mac Neice/Hesse (10-15 min)
CISM ?
Others ?
Discussion (30-35 min)
Confirmed participants:
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Eparvier, Woods, Chamberlin, Woodraska, & Hock from EVE instrument team
Viereck, Tobiska, MacNeice or Hesse, Didkovsky, HMI SWx reps, AIA SWx
reps, Others
Wednesday, 2:30 p.m.
Vector Magnetic Field Inversions - Technical Splinter
Leaders: Steve Tomczyk & Juan Borrero
Technical working session for small group involved in vector magnetic field inversions
with HMI data.
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2:30 How to choose the most adequate inversion technique for spectropolaimetric
data, Basilio Ruiz
2:45 Community Spectro-polarimetric Analysis Center (CSAC), Bruce Lites
3:00 Quick-look vector field data products: emphasis on Space Weather
forecasting, Steven Tomczyk
SDO Teams Meeting
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3:15 Standard vector field data products: HMI inversion algorithm, Juan M
Borrero
3:30-4:00: Discussion
o Quick-look data products for space weather forecasting
o What are the important data products?
o To what accuracy are they needed?
Wednesday @ 4:15 p.m.
Knowledge Base Tools INPUT: Surface-to-Heliosphere
Events
Leader: K. Schrijver
Focus on: surface-to-heliosphere events
Products: prioritized list, working groups, tasked co-Is
This session discusses events from the solar surface into the heliosphere.
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What kinds of events should be identified?
What tools exist or need to be developed to identify the events and quantify their
properties?
What parameters should be derived/measured?
The outcome of the sessions should be a prioritized list of events that will be of most use
for the community, plus plans on how to incorporate, find, and validate these.
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10 min. Schrijver: Discussion: what types of events are needed, and what kinds of
metrics/attributes should quantify them?
10 min. Nitta: Flares and CMEs
10 min. De Pontieu: Oscillation events
5 min. Ireland: The SIPWORK community: activities and tools
10 min. Berghmans: Feature finding and catalogs in Brussels
5 min. Eparvier: Feature needs from the irradiance perspective
Remainder: open discussion
Wednesday -4:15 p.m.
Knowledge Base Tools - Model Events
Leader: Mark Cheung
As demonstrated in the Wednesday morning session for the Heliophysics Knowledge
Base, we have laid down the infrastructure for a unified repository of features and events
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detected in solar and heliospheric observations. For the purposes of comparison between
models and observations, and for forecasting applications, it is equally important that the
Knowledge Base be able to support features and events from data-driven simulations.
In this session, we will
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Provide examples of how some `model events' can naturally be included into the
current implementation of the Knowledge Base
Explore possible improvements in design to accommodate further categories of
model events and features
Discuss how to link the Knowledge Base to existing and upcoming model
repositories such as the CCMC.
Wednesday @ 4:15 p.m.
Local HS 3: Subsurface Flows; Near-surface and
Magnetic Effects
Leaders: Brad Hindman, Charlie Lindsay, & Junwei Zhao
1. Helioseismic Signatures of Near-Surface Magnetic Fields (Doug Braun)
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What are the helioseismic signatures of near-surface anomalies?
What are the effects of these on diagnostics of underlying thermal structure,
flows, magnetic fields and other local physical anomalies in the solar interior?
What are the effects of various filtering and other analytical techniques applied to
seismic observations containing the signatures of near-surface anomalies?
What can the above effects tell us about active region structure and dynamics
(mode conversion, for example)?
What can/should be done about prospective artifacts caused by near-surface
anomalies?
2. Further Magnetic Effects in Helioseismic Signatures (Paul Rajaguru)
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What helioseismic signatures can be caused by variations in line profiles due to
Zeeman splitting?
What supporting research can/needs to be done to separate these signatures from
those of flows, sound-speed anomalies and other objects of helioseismic
diagnostics?
What are the effects of phase-speed filtering on helioseismic diagnostics of
thermal structure and flows beneath active regions?
Can these be credibly accounted for? If so, by what means?
3. The Role of MHD Simulations in Helioseismic Diagnostics (Konstantin Parchevsky)
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What is the practicality of credible simulations of near-surface acoustics in the
quiet Sun and active regions?
What kinds of seismic environments can be simulated?
What is the role of fully compressible simulations of convection with and without
magnetic fields?
4. Large-Scale Flows (Rudi Komm)
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What is needed for diagnostics of large-scale flows in the HMI era?
What are the effects of surface magnetic regions on seismic diagnostics of large
scale flows, and how can we devise a realistic account for them?
What resources do we need to understand what drives large-scale flows?
5. Testing Helioseismic Methods for HMI (Aaron Birch)
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What are the major control issues surrounding flows and near-surface and
magnetic effects as presently understood?
What can MHD simulations give us for testing helioseismic models of local solar
interior anomalies?
What is needed to derive realistic artificial data from simulations?
What control facilities can be developed without recourse to detailed MHD
simulations?
--A Closely Related Topic in Session on KB Tools - Helioseismic & Magnetic Events
(Friday @ 10:30 a.m.)
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What can seismic emission from flares tell us about the mechanics of flares in the
HMI era?
What control facilities does seismic emission from flares offer for helioseismic
diagnostics?
What can seismic emission from flares tell us about the thermal structure and
dynamics of the solar interior underlying magnetic regions?
What supporting observations of acoustically active flares would be useful?
What is the prospective utility of a white light flare alarm from the HMI pipeline
in the solar and space-weather community at large?
What is the practicality of such a flare alarm?
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Thursday @ 8:30 a.m.
Science Plenary
Leader: Alexander Kosovichev
8:30 Links Between Internal Processes and the Dynamics of the Corona and
Heliosphere , Rudi Komm
NSO
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Active regions (magnetic fields, in general) provide a point of contact between
helioseismic studies of the upper convection zone and studies of the solar
atmosphere. Helioseismic observations allow us to derive in detail subsurface
flows and sound-speed structures associated with active regions. Recent
helioseismic studies have shown, for example, that subsurface flows associated
with active regions are very complex and highly twisted and that their twisted
nature is related to the flare production of active regions. In this context, it is of
interest, for example, to find out how the kinetic helicity of subsurface flows
relates to the magnetic helicity of flux tubes. Helicity-loaded fields are very
probably responsible for the most geoeffective solar phenomena such as coronal
mass ejections and flares. Events in the solar atmosphere can, on the other hand,
produce seismic responses such as sunquakes, acoustic events generated by flares.
These sunquakes appear to be related to the acceleration and propagation of
electrons and ions during the impulsive phase of solar flares. Inclined magnetic
field lines can provide, quite literally, a link between interior and atmosphere
acting as magnetoacoustic `portals' that allow waves, which are evanescent in a
non-magnetic atmosphere, to propagate into the chromosphere. I will discuss
some of the latest results and what SDO can do for understanding these links.
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9:00
Energy Storage & Release in Solar Flares , Terry Forbes
UNH
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Most present-day models of flares are based on the principle that the energy that
drives them comes from the magnetic energy associated with stressed magnetic
fields in the solar corona. A primary question regarding models of this type is the
nature of the mechanism that triggers the energy release. One attractive possibility
is that onset is triggered by a combination of ideal (e.g. loss of equilibrium) and
non-ideal (e.g. magnetic reconnection) processes acting together. The first process
can explain the rapid onset of the eruption, but the second is needed to explain the
large scale of the energy release. Although quite a few models are currently being
developed, many important questions about flares remain unanswered. For
example, how are the currents in the corona created, and what form do they take
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in a three-dimensional configuration? Can models of the above type account for
the acceleration of energetic protons and electrons? What kind of interaction
occurs between the erupted field and the surrounding non-erupted field and can
such interactions be detected?
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9:30 Evolution, Dynamics and Heating of Coronal Magnetic Flux Ropes , Aad
van Ballegooijen
SAO
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The coronal magnetic field is anchored in the photosphere and continually
evolves in response to changes in the photospheric boundary conditions. At the
photosphere the field is concentrated into discrete flux elements that exhibit
various random and systematic motions, and these elements frequently split-up or
merge with each other. New flux emerges in the form of twisted bipoles that
reconnect with preexisting coronal fields, and magnetic flux may be removed
from the corona by submerging below photosphere. All of these effects cause
electric currents to be induced in the corona, producing a complex magnetic field
that deviates significantly from a potential field. The strongest deviations occur
near polarity inversion lines where highly sheared, weakly twisted magnetic fields
can exist for long periods of time. These "coronal flux ropes" contain large
amounts of magnetic free energy and helicity. Occasionally the flux ropes erupt,
causing helicity to be ejected into the heliosphere.
In this talk I describe various models for the structure, dynamics and heating of
coronal flux ropes. Global models describe the evolution of the coronal field on
time scales of many months, and are important for understanding how the helicity
that emerges in active regions is spread over the quiet Sun. Local models describe
how coronal flux ropes interact with the dynamic flux elements in the
photosphere. I also discuss a new theory for plasma heating in coronal flux ropes.
According to this theory, the energy dissipated in flux ropes has two distinct
contributions: one from photospheric footpoint motions, and another from the
magnetic free energy of the flux rope. It is assumed that flux ropes contain
stochastic magnetic fields, and that small-scale reconnection occurs at many sites
with the flux rope. The effect of such reconnection on the mean magnetic field is
described in terms of hyperdiffusion, a type of magnetic diffusion in which the
magnetic helicity of the mean field is conserved (Taylor relaxation). Initial results
from modeling the hyperdiffusive heating of coronal flux ropes are presented.
SDO Teams Meeting
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Thursday @ 10:30 a.m.
Coronal Magnetic Field Tools and Models II: Nonlinear
Force-Free Models
Leader: Marc DeRosa
In this session we will discuss non-linear force-free coronal magnetic field models. The
candidate models will be discussed, along with the associated issues of how to perform
the preprocessing and validation of these models. We would like to determine which
model to run, and how often, taking into account the uncertainties in the resulting
magnetic field models.
Schedule




10:30 Session intro (DeRosa)
10:40 NLFFF preprocessing/methods overview (Wiegelmann)
11:00 Loop tracing methods overview (Aschwanden)
11:15 Community discussion (DeRosa)
Possible topics for the discussion session:
1. Given the current state of NLFFF modeling and validation, which model results are
useful to the science community? Should the results be available, warts and all?
2. How often should the NLFFF models be run? Given the currently budgeted
computational resources, we will likely have to trade off between the methods and the
regions of interest.
3. Do we need additional resources to develop better H-alpha data (for the
preprocessing), better loop tracing algorithms (for automated validation)?
Thursday @ 10:30 a.m.
EVE and the Solar Spectral Irradiance
Leader: Harry Warren
This will be a discussion of the data products and modeling needed to derive the next
generation of solar EUV and soft X-ray irradiance models. Here we will also consider the
status of the EVE calibration algorithms and the cross calibration between EVE and AIA.
The relationship between EVE and other long term data sets (e.g., TIMED/SEE) will also
be discussed.
SDO Teams Meeting
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Brief Talks (40-50 minutes total)




Status of EVE calibration and data processing algorithms (Frank Eparvier)
o If EVE started returning data today would we be able to produce
calibrated data products?
Cross Calibration of EVE and AIA (Harry Warren)
o This presentation will discuss several algorithms for cross calibrating the
AIA imagers with the EVE spectral irradiance measurements.
Overview Talk: Recent EUV and XUV Irradiance Measurements and Models
(Phil Chamberlin)
o This talk will focus on the strengths and weaknesses of recent solar
irradiance measurements and the irradiance variability models derived
from them.
Sources of EUV Irradiance Variability (Tom Woods)
o This talk will give a brief overview of some previous work on associating
solar variability with the evolution of photospheric, chromospheric, and
coronal features.
Discussion Topics (50-40 minutes total)


Requirements for future model development
o How will we use SDO observations from EVE, AIA, and HMI to produce
the next generation of solar irradiance models? What will the main
approaches be? Pixel-by-pixel DEM? Proxies for solar activity?
Decomposition of solar features? What SDO data products will we need
and what development needs to be pursued to bring them together?
Documenting Operational EUV Models (Kent Tobiska)
Thursday @ 10:30 a.m.
HS 4: SDO Helioseismology Pipeline & Data Products
Leaders: Rick Bogart & Sasha Kosovichev
Agenda (90 min)

Data preparation: tracking, remapping, processing strategy,data for testing and
validation (25 min)
o Status and plans: R. Bogart (10 min)
o Discussion (15 min)
o Data types:
 a) synoptic
 b) AR
 c) events (emerging flux, flares, CMEs, etc)
 d) validation
 e) intercomparison with MDI and GONG
SDO Teams Meeting
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



Ring-diagram pipeline: Status & Schedule (25 min)
o Organization and data products - R.Bogart (10 min)
o Techniques and discussion (15 min)
Time-Distance Helioseismology (TDH) pipeline Status & Schedule (25 min)
o Organization and data products - A.Kosovichev (5 min)
o Techniques, performance and testing - J.Zhao (10 min)
o Discussion (10 min)
Far-side Imaging pipeline Status & Schedule (5 min)
o Data products and implementation - P. Scherrer (5 min)
General discussion (10 min)
Thursday @ 10:30 a.m.
Technical Session on Coronal Oscillations - I
Leader: Bart DePontieu
First of three technical discussion group focused on developing software that
automatically finds locations of significant oscillatory power in the corona.
Introduction on issues facing automated software that searches for locations of significant
oscillatory power (reliability, false positive, CPU load, distinguishing
longitudinal/transverse/moss oscillations, etc...) [10 min, Bart De Pontieu]
Brief talks by Valery Nakariakov, Jack Ireland, Ineke De Moortel, Bart De Pontieu on
results of their codes [15 min each]
Discussion of first results
Thursday @ 2:30 p.m.
Coronal Magnetic Field Tools and Models III: MHD
Models
Leader: Bill Abbett
This session will focus on dynamic models. We will first describe several promising
techniques that allow photospheric flows and electric fields to be determined from timesequences of magnetograms. We will then discuss the utility and efficiency of these
methods, how they are validated, and how they might be included as pipeline products.
Next, we will focus on the available MHD models --- their capabilities and limitations,
how they are validated, and how best to incorporate these models into the suite of user
tools.
SDO Teams Meeting
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




2:30 - Introduction, W. Abbett
2:35 - Determining Surface Flows & Electric Fields from Vector Magnetograms,
G.H. Fisher
2:55 - Discussion & Planning, B.T. Welsch
3:05 - MHD Models
o 3:05 Deducing Active Region Fields and Plasma Properties Using 3D
MHD Models with Measurements as Input, S.T. Wu
o 3:25 Global MHD Modeling in Support of SDO, J. Linker
3:45 - Discussion & Planning
Thursday @ 2:30 p.m.
Space Weather - Photons
Leader: Frank Eparvier
This session will focus on solar irradiance impacts on the geospace environment with the
following guiding questions:



What are the irradiance forecasting/nowcasting needs of operational community?
What's missing that SDO can provide?
What tools need to be developed for SDO data to be used for space weather?
Agenda (90 minutes)








Introduction, Eparvier (5 min)
Currently Planned EVE SWx Products, Eparvier (10 min)
Special topic: EVE helping with the current NOAA XRS crisis,
Eparvier/Viereck/Woods (10 min)
AIA/HMI Potential Irradiance-Related SWx Products, HMI rep/AIA rep (10 min)
The NOAA/SWPC Perspective, Viereck (10 min)
An Operational Irradiance Modeler's Perspective, Tobiska (10 min)
The GAIM Perspective, Tobiska/Viereck (10 min)
Discussion (25 min)
Thursday @ 2:30 p.m.
Global Helioseismology 5: Harmonics & Peak Bagging
Leader: Jesper Schou
Spherical Harmonic Generation


To what maximum degree, l, do we go?
Time series length?
SDO Teams Meeting
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

Both V and I?
Gapfilling?
Contributions welcome!
Peakbagging




Which methods will run in the pipeline by launch (in addition to J. Schou's) ?
What length time-series and degrees?
What other options?
What are the advantages of the alternate methods at various degrees.
Likely speakers: Rachel Howe, Tim Larson, Ed Rhodes, Sylvain Korzennik/Cristina
Coares
Additional contributions welcome!
Thursday @ 2:30 p.m.
Technical Session on Coronal Oscillations - II
Leader: Bart DePontieu
Continuation of small technical discussion group focused on developing software that
automatically finds locations of significant oscillatory power in the corona.
This session focuses on discussion of the effects of rebinning (how much can we rebin
before losing crucial information), derotating data, despiking data, time range, etc... on
finding locations with significant oscillatory power with the various codes.
Thursday @ 4:15 p.m.
Coronal Magnetic Field Tools and Models IV: Topology
Leader: Y. Liu
This session will focus on determination of topology structure in solar active regions.
Recent studies show that topology structure can effectively classify active regions and
pinpoint locations where magnetic reconnection occurs that leads to occurrence of solar
eruption. Many techniques have been reported to be able to determine topology using
observational data, and some of them shows potential to be robust and automatic. In this
session, we will first describe several promising techniques. We will then discuss the
tools to effectively present the topology result in a way that people can easily understand.
Next we will discuss any possibilities for putting this structure into the pipeline as a
product. We will also discuss matrix for validation of the results. We end up with a
SDO Teams Meeting
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discussion whether or not we need a working group on this topic, and what the plan will
be if we want to have one.
Schedule:




4:15 Coronal Magnetic Topology: How to Characterize it --- and Why (D.
Longcope)
4:45 Topological Evolution & Magnetic Reconnection (C. Parnell)
5:05 The structure of eruptive magnetic fields and its relation to observational
features" (V.S. Titov, Z. Mikic, J.A. Linker, and R. Lionello)
5:25 Community discussion (Y. Liu)
Discussion topics:
1.
2.
3.
4.
5.
6.
Find the best way to present topology structure
Which algorithm potentially to be automated
Validation
Ready to be a pipeline product?
Need a working group?
Plan toward a pipeline module
Thursday @ 4:15 p.m.
Vintner's Ballroom
DEM - Differential Emission Measure - Part 1
Leaders: Mark Weber and Paul Boerner
This is the first of two sessions on using AIA data for thermal (especially DEM) analysis.
In this session, we will discuss the techniques and challenges of constraining a DEM
using AIA, including instrumental calibration; atomic and plasma physics; spectral codes;
and inversion techniques.
Brief Talks



Regina Soufli (~10 min + discussion): Calibration of the EUV bandpasses on AIA
Vinay Kashyap (~20 min + discussion): Overview of atomic physics issues;
statistical uncertainties in DEM inversion
Additional brief talks on DEM inversion techniques/applications welcome
Discussion Topics
In addition to the discussion of the specific issue raised in the talks, we will attempt to
cover some of the broader issues, such as:
SDO Teams Meeting
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


What is the best way to identify and track the uncertainties in DEMs obtained
from AIA data?
What can be done to reduce the uncertainties involved in the instrument
calibration, abundances, line strengths, and other atomic/plasma physics issues
that go into DEM analysis?
What inversion techniques are likely to prove most appropriate for AIA?
Thursday @ 4:15 p.m.
Global Helioseismology 6: Inversions and the MDI>HMI Transition
Leader: Jesper Schou
Inversions


Which code are we going to have running?
How automated?
Likely speakers: Sarbani Basu/Charles Baldner
Additional contributions welcome!
The MDI to HMI Transition


What types of comparisons/validations do we do?
Dopplergrams? Time-series? Power spectra? Mode parameters? Inversions?
Likely Speaker: Rachel Howe
Additional contributions welcome!
Thursday @ 4:15 a.m.
NVB:Stag's Leap
Trying out the Heliophysics Knowledge Base
Leader: KB Team
Get some hands on experience with the Knowledge Base as it is currently implemented.
SDO Teams Meeting
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Friday @ 8:30 a.m.
Collaborative Science - SDO's contribution to the Great
Observatory
Leader: Mark Cheung
This brief introduction to a discussion of Collaborative Science will include two 10minute talks


S. Gibson - Science Planning of Coordinated Observing Campaigns: Lessons for
the SDO Era
K. Reeves - Coordinating observations: Lessons Learned and Wish List
We will then break into three splinter sessions to discuss ways to organize collaborative
science.
SDO will make a key contribution to coordinated solar/heliospheric observational
campaigns. Although SDO will provide continuous full-disk coverage, there is still a
critical role for the active participation of SDO science teams in the planning of
coordinated science campaigns. The reason is simple: given the immense data volume
expected from SDO, one must plan in advance the best way to extract data from the
archive not already delivered by the standard data pipeline (e.g. disambiguated vector
magnetograms at a very high cadence, DEM inversions at full AIA resolution for a
subregion etc.). In short, one must plan to "observe the SDO data archive."
Friday @ 9:00 a.m.
Heliophysics Observatories Bulletin Board: Design and
implementation
Leaders: Mark Cheung
The aim of setting up a Heliophysics Observatory Bulletin Board is to encourage
coordinated Heliophysics observations even when no joint observing programs have been
planned and agreed upon. The concept of the Bulletin Board is to allow observers using
different instruments/observatories to post up-to-date information (e.g. field of view of
telescope) about their most recent (e.g. last 24 hours), current and planned upcoming (e.g.
next 24 hours) observations. The anticipation is that if everyone knows what everyone
else is/was observing, there will be a better chance of matching up complementary data
sets for collaborative science studies.
One possible design of the Bulletin Board may simply be a webpage with an SDO image
of a solar disk, overlaid with bounding boxes indicating the fields of view of different
SDO Teams Meeting
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observatories in the same time period. Latest events and features from the Heliophysics
Knowledge Base may also be included to provide context.
Everyone is invited to participate in the discussion to help design this system.
Friday @ 9:00 a.m.
Campaign Coordination in the SDO Era
Leaders: Sarah Gibson & Kathy Reeves
SDO will routinely provide comprehensive synoptic support for observing campaigns,
but also has specific contributions it can make to campaigns. These include helpful
resources for the planning process (daily summary observations etc.) but also special
methodologies for observing the SDO data archive in ways that may be different than
routine data processing pipeline.
In this splinter session we will discuss the state of the art in terms of resources for
planning and coordinating observing campaigns, and assess what works well (or doesn't
work well) already. We will consider what resources are missing or should be developed
in light of the unique demands of future observations (e.g. high volume, etc.).
Friday @ 9:00a.m.
Technical Session on Coronal Oscillations - III
Leader: Bart DePontieu
Conclusion of small technical discussion group focused on developing software that
automatically finds locations of significant oscillatory power in the corona.
We wrap up with discussions of how to proceed with interfacing with the knowledgebase,
how to distinguish longitudinal/transverse/moss oscillations in an automated fashion, how
to analyze properties of oscillations/waves in an automated fashion, etc...
Friday @ 10:30 a.m.
Magnetic Connections to the Heliosphere
Leader: Kelly Korreck
Likely presenters: Barbara Thompson, Kelly Korreck
SDO Teams Meeting
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In order to utilize the SDO data to the fullest, the solar data must be linked through
modeling and observation to the heliosphere. Several models already exist and are readily
available at the CCMC. The goals of this session:




To identify complementary data sets that can be used with SDO- EVE, AIA, and
HMI data (for example, ACE SWICS data, Stereo or Ground based radio
observations)
Identify the science topics that can reap the most benefit from the collaboration
o Source Regions of the solar wind
o CME initiation, liftoff and propagation
o Composition and Temperature of unprocessed solar wind
To identify the current and/or future models (MHD, energetic particle transport
etc) that will aid in this comparison
To determine ways in which the CCMC can become involved with the larger
effort
Agenda






10:30-10:35 Introduction to Session (Korreck)
10:35-10:50 Links of SDO data products to Heliosphere (Thompson)
10:50-11:05 LWS Capabilities (Marc DeRosa)
11:05-11:20 CISM plans (TBC)
11:20-11:40 Identify the SDO/Heliospheric data links and responsible individuals
for their creation
11:40-12:00 Identify the SDO/Heliospheric coding connections and the
responsible individuals
The last two items will be open discussions to look specifically at the goals of this session
and identify the next action steps.
Friday @ 10:30 a.m.
Vintner's Ballroom
DEM - Differential Emission Measure - Part 2
Leaders: Mark Weber and Paul Boerner
Thermal studies with AIA
This is the second of two sessions on using AIA data for thermal (especially DEM)
analysis. In this session, we will focus on the application of DEMs or related thermal data
products from AIA. In particular, we will focus on two questions:

How can DEMs be used to gain a deeper understanding of the physics of the solar
atmosphere? How do they interface with physical models of coronal structures?
SDO Teams Meeting
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
Should there be an "automated DEM data product" that continuously produces
thermal maps or shorthand DEMs at some substantial fraction of the AIA cadence
and resolution? If so, what should that automatic DEM data product look like?
What would it be used for?
Brief Talks


Markus Aschwanden (~10 minutes + discussion): forward-modeling of theoretical
DEMs (based on hydrodynamic evolutions of heating and cooling processes) to
observations
Mark Weber/Paul Boerner (~20 minutes + discussion): the Automated DEM data
product; responses to a survey of potential end-users, and presentation of a
strawman data product concept
Discussion Topics
In addition to the discussion of the specific issues raised in the talk, we will cover the
broader issues of how DEMs can be used to do science, and how DEM-related thermal
data products can be used to enhance the value of the AIA data
Friday @ 10:30 a.m.
Grand Ballroom: Syrah & Merlot
Knowledge Base Tools INPUT: Helioseismic &
Magnetic Events
Leader: S. Kosovichev
This session discusses events below the solar surface that will be identified and analyzed
with helioseismic tools, and related to the surface events and features. What kinds of
events should be identified? What tools exist or need to be developed to identify the
events and quantify their properties? What parameters should be derived/measured? The
outcome of the sessions should be a prioritized list of events that will be of most use for
the community, plus plans on how to incorporate, find, and validate these.








A.Kosovichev, Introduction (5 min)
A. Pevtsov, Characterization of magnetic properties of active regions (10 min)
M. Hagenaar, Identification of emerging and ephemeral active regions (10 min)
D. Haber, Characterization of sub-surface flows of emerging and evolving active
regions (10 min)
R. Nightingale, Detection and characterization of rotating sunspots (10 min)
H. Wang, Characterization of pre-flare magnetic structures and flows (10 min)
I. Gonzalez Hernandez, Identification of far-side events (10 min)
C. Lindsey, Detection of flare oscillations and white-light flares (10 min)
SDO Teams Meeting
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
General discussion (15 min)
Friday @ 1:30 p.m.
AIA Early Observing Modes
Leader: Alan Title
Discussion of early modes of observation with the AIA instrument
Friday @ 1:30 p.m.
Knowledge Base: Technical Session on Keywords,
Metadata, and IDs
Leaders: Neal Hurlburt


Reports from Weneday KB Sessions, Session 'secretaries'
Task list
This session will collect the results from the earlier knowledgebase sessions, and translate
the discussions into lists of event types, their attributes, and properties.
A task list will be compiled along with an implementation plan for the next 12 months.
Friday @ 3:30 p.m.
SDO Science Working Group
Leaders: Dean Pesnell
Publication of Instrument Papers and other SDO science team project and programmatic
topics
SDO Teams Meeting
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
Author: Markus J. Aschwanden
Institution: LMSAL
Email: aschwanden@lmsal.com
Poster Title:
Coronal Loop Modeling with non-equilibrium hydrodynamic models
Abstract:
We approximate the hydrodynamic evolution of the heating and cooling
phase of coronal loops with analytical models that reproduce the nonequilibrium states, which allows us to model data analysis of EUV data
from SOHO, TRACE, STEREO, HINODE, and SDO/AIA. Using these models we
retrieve information onthe non-equilibrium heating and cooling phases.
SDO Teams Meeting
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Author: Auchere, F., Soubrie, E., Bocchialini, K.
Institution: Institut d'Astrophysique Spatiale
Email: frederic.auchere@ias.u-psud.fr
Poster Title:
FESTIVAL: A Multiscale Vizualisation Tool for Solar Images
Abstract:
We present here FESTIVAL, a SSW package originally developed to be able
to map the SECCHI data into dynamic composite images of the sky as seen
by the STEREO and SOHO probes. The five SECCHI instruments image the
solar corona and the heliosphere on a wide range of angular scales,
which causes a data visualization challenge. Similarly, the very large
format of AIA data will prevent them from being visualized at once on a
computer display. With FESTIVAL, the user can quickly and easily (with
the mouse) zoom in and out and pan through these composite images to
explore all spatial scales from EUVI to HI2 while keeping the native
resolution of the original data. A large variety of numerical filters
can be applied, and context data (i.e. coordinate grids, stars
catalogs, etc.) can be overlaid on the images.
SDO Teams Meeting
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Author: V. Barra, V. Delouille, J.-F. Hochedez, J.M. Krijger
Institution: SIDC, Royal Observatory of Belgium ; LIMOS, Université
Blaise Pascal Clermont II
Email: krijger@sidc.be
Poster Title:
SPoCA: A Spatial Possibilistic Clustering Algorithm for EUV images
Abstract:
The study of the variability of the solar corona and the monitoring of
its traditional regions (Coronal Holes, Quiet Sun and Active Regions)
are of great importance in astrophysics as well as in view of the Space
Weather and Space Climate applications.
We propose 'SPoCA', a Spatial Possibilistic Clustering Algorithm that
automatically segments EUV solar images into Coronal Holes, Quiet Sun
and Active Regions. The use of fuzzy logic allows to manage the
imprecision in the definition of the above mentioned regions. The
process is fast and automatic. Moreover, when combined with a movement
estimation method it allows to track Active Regions and Coronal Holes.
SPoCA is applied to SoHO-EIT images taken from January 1997 till May
2005, spanning thus almost a full solar cycle. Results in terms of
areas and intensity estimations are consistent with previous knowledge.
The method reveal the rotational and other mid-term periodicities in
the extracted time series across solar cycle 23. Further, such an
approach paves the way to bridging observations between spatially
resolved data from imaging telescopes and time series from radiometers.
SDO Teams Meeting
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Author: J.G. Beck, J Zhao, T.L. Duvall, Jr
Institution: Stanford Solar Observatories Group
Email: Beck@Sun.Stanford.EDU
Poster Title:
Time-Distance Errors Due to Data Gaps
Abstract:
Time-distance measurements have provided a wealth of information about
the layers beneath the photosphere. Cubes of tracked data are analyzed
to find cross-correlations in the wave signals at different spatial
locations. These cross-correlations yield travel times for wave
packets which can be interpreted as various properties of the plasma
through which the wave propagate. Often there are images which are
missing or of low quality which must affect the cross-correlations and
travel-time measurement. We examined the errors in travel time (and
dependent quantities) due to data gaps in the time-series and compare
common gap-filling techniques.
SDO Teams Meeting
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Author: Kelly Beck
Institution: Haas Center for Public Service, Stanford University
Email: kbeck@stanford.edu
Poster Title:
Science in Service: Developing Leadership in Science Outreach
Abstract:
As part of their SDO outreach efforts Phil Scherrer and the Stanford
Solar Observatories Group partnered with Stanford University's Haas
Center for Public Service to develop a k-12 outreach program that
involved the University's undergraduate science students. This paper
will describe the resulting program called Science in Service, through
which Stanford students are trained in best practices for teaching
science and in principles of effective public service. The students
then mentor science to children in local after-school programs.
Details of the program will be described.
SDO Teams Meeting
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Author: Kevin Belkacem, Reza Samadi, Marie-Jo Goupil
Institution: Observatoire de Paris - Meudon
Email: kevin.belkacem@obspm.fr
Poster Title:
On the Amplitude of High-Angular-Degree P Modes
Abstract:
We have recently generalized the formalism of stochastic excitation of
radial p modes to non-radial ones, which enables us to estimate the
energy supplied to high-angular degree acoustic modes. We present the
theoretical results obtained for those modes and emphasize the
necessity to obtain accurate enough observational data for both the
height and line-width of modes so as to get physical constraints on the
upper-most layers of the solar
convection zone.
SDO Teams Meeting
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Author: Elena E. Benevolenskaya
Institution: Stanford University
Email: elena@sun.stanford.edu
Poster Title:
Relationship between EUV corona and phospheric magnetic activity.
Abstract:
Solar Dynamic Observatory is coming to provide us EUV coronal and
vector magnetic field data. It helps more detaily understand a
relationship of the coronal and photospheric activity in the new solar
cycle 24. Because of, the solar corona in Extreme-Ultraviolet emissions
is visible on the solar disk, it is a good opportunity to investigate
the coronal and magnetic activity, simultaneously.
Now, the EUV data of Extreme Ultraviolet Telescope (EIT) on board SOHO
are available since 1996 up to the present time. And, here, we have
represented the EUV data from SOHO/EIT in four wavelengths (171A, 195A,
284A, and 304A) in the form of coronal synoptic maps for 1996-2006.
Our results reveal that the evolution of the coronal structure is
closely related to the changing of the topology the magnetic activity.
EUV synoptic investigations also find a strong solar cycle dependence
which is presented in high and mid latitude.
SDO Teams Meeting
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Author: T. E. Berger
Institution: Lockheed Martin Solar and Astrophysics Lab
Email: berger@lmsal.com
Poster Title:
Hinode/SOT Observations of plume upflows, cascading downflows, and
oscillations in quiescent solar prominences
Abstract:
The Solar Optical Telescope (SOT) instrument on the recently launched
Hinode satellite has obtained new observations of solar prominences in
both the Ca II 396.8 nm “H-line” and the H I 656.3 nm Balmer-alpha
(Hα) spectral bandpasses. The SOT prominence observations are
characterized by spatial resolutions from 170 to 220 km, temporal
resolutions of 30 to 40 seconds, and unprecedented temporal stability :
5 hour duration, diffraction-limited, movies of prominences are
regularly obtained by the SOT. Here we show preliminary analyses of
the prominence dynamics observed by SOT. One of the most striking SOT
discoveries to date is the observation of impulsive dark upflows
frequently seen ascending with ~20 km/sec speeds in quiescent
prominences. The upflows originate below the prominence, show turbulent
flow structuring, and rise to heights of 10--20 Mm above the
photosphere. The dynamics of the flows implies that they are buoyant
thermal plumes generated by an episodic mechanism in the photosphere or
lower chromosphere. The existence of the plumes has implications for
the prominence and cavity mass balance.
SDO Teams Meeting
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Author: T. E. Berger, G. L. Slater, R. Shine, T. D. Tarbell, A. M.
Title, B. Lites, J. Okamoto, Y. Katsukawa, K. Ichimoto, Y. Suematsu, T.
Sekii, T. Shimizu, S. Tsuneta
Institution: LMSAL, NAOJ
Email: berger@lmsal.com
Poster Title:
Hinode/SOT Observations of Plume Upflows, Cascading
Downflows, and Oscillations in Quiescent Solar Prominences
Abstract:
We present the latest findings on quiescent prominence structure and
dynamics from the Hinode/SOT instrument. The data show that quiescent
prominences appear in two broad classes: vertically and horizontally
structured. The reason for the delineation in appearance is not clear
but may be related to line-of-sight angle and/or magnetic field
strengths. In vertically structured prominences SOT observations reveal
constant downflow streams with speeds of ~10 km/sec, frequent vortex
flows, large scale "body" oscillations with periods on the order of 10
minutes and propagation speeds of ~10 km/sec, and, most surprisingly,
episodic dark turbulent plume upflows with speeds of ~20 km/sec. The
dark plumes originate below the base of the prominence and propagate
upward to typical heights of 10 Mm or more. The speed of the plumes is
relatively constant, as expected for thermal plumes balanced by fluid
dynamic drag. The plumes represent a new source of prominence mass and
may play a significant role in maintaining prominence structure against
gravitational draining in the downflows.
SDO Teams Meeting
38
Author: D. Berghmans and the SWAP team
Institution: Royal Observatory of Belgium
Email: david@oma.be
Poster Title:
SWAP, yet another EUV imager launched soon
Abstract:
SWAP is a small EUV imager onboard PROBA2, an ESA technology
demonstration platform. SWAP will image the solar corona in 17.5nm on a
1024x1024 CMOS APS detector at a 1 min cadence. PROBA2 was originally
planned for launch in 2005 and would have been a useful addition to EIT
(but with higher time resolution) and EUVI (but Earthbound). However,
due to several delays, PROBA2 will now be launched in mid 2009 and will
thus fully overlap with the SDO/AIA lifetime. In this poster we will
explore the potential of SWAP and its possible synergies with the AIA
imagers.
SDO Teams Meeting
39
Author: D. Berghmans, B. Nicula, C. Marque
Institution: Royal Observatory of Belgium
Email: david@oma.be
Poster Title:
The Solar Weather Browser, Recent Progress and Usage for AIA
Abstract:
We present version 1.2 of the Solar Weather Browser (SWB). The main
innovation is its capability to combine data and metadata from multiple
sites. This is important in relation to data distributed over
different servers at different sites, as in Virtual Observatory
networks. For example, the SWB will be the reference visualization
platform for SOTERIA, a network of solar ground-based observatories
funded by the EU. In this poster we will address in particular, our
plans for visualizing AIA data and combining with metadata extracted
from feature recognition processing chain developed at ROB.
SDO Teams Meeting
40
Author: Luca Bertello, Roger K. Ulrich, John E. Boyden, and L.Webster
Institution: University of California, Los Angeles
Email: bertello@ucla.edu
Poster Title:
Calibration of the magnetic field Strength
Abstract:
Photospheric magnetic field maps are the primary drivers of coronal and
heliospheric models, and their calibration will ultimately test the
diagnostic capabilities of these models. The determination of the solar
magnetic field strength is one of the most difficult tasks in the
construction of these maps. It is however a critical step to proper
model the heliosphere. The solar physics group at UCLA has dedicated an
extensive effort to this task, in particular with the interpretation of
MDI and MWO magnetic field strength observations.
In an effort to improve our knowledge for the calibration of the future
magnetic observations made by the HMI instrument aboard SDO, we have
carried out a new series of observations aimed at establishing a more
complete understanding of the scale factors relating different
observing methodologies for determining the photospheric field
strength.
During the interval 18 April 2007 to 8 May 2007 a set of five special
magnetograms were obtained using the 24-channel system at the 150-foot
solar tower telescope on Mount Wilson. The special spectrograph
configuration used for these observations allowed us to compute the
magnetic field from five different spectral sampling pairs of FeI 5233,
in addition to the standard sampling of FeI 5250 usedas a part of the
Mount Wilson synoptic program of magnetic observations. The analysis
of these measurements and the main results are described in this
poster. In particular, we derived a new scale factor to obtain
unsaturated estimates from FeI 5250 magnetic field measurements which
would have been measured at FeI 5233.
SDO Teams Meeting
41
Author: S. Buhr, M. McCaffrey, M. Murillo, F. Eparvier
Institution: CIRES, St. Vrain School District and MESA program, LASP
Email: mark.mccaffrey@colorado.edu
Poster Title:
A Partnership Between English Language Learners and a Team of Rocket
Scientists: EPO for the NASA SDO Extreme Ultraviolet Variability
Experiment
Abstract:
Extreme-Ultraviolet Variability Experiment (EVE) project. The students
were enrolled in a pilot course as part of the Math, Engineering and
Science Achievement MESA) program. For many of the students, this was
the only science option available to them due to language limitations.
The English Language Learner (ELL) students doubled their achievement
on a pre- and post-assessment on the content of the course. Students
learned scientific content and vocabulary in English with support in
Spanish, attended field trips, hosted scientist speakers, built and
deployed space weather monitors as part of the Stanford SOLAR project,
and gave final presentations in English, showcasing their new computer
skills. Teachers who taught the students in other courses noted gains
in the students' willingness to use English in class and noted gains in
math skills. The MESA-EVE course won recognition as a Colorado MESA
Program of Excellence and is being offered again in 2007-08. The course
has been
Broken into modules for use in shorter after-school environments, or
for use by EVE scientists who are outside of the Boulder area. Other
EVE EPO includes professional development for teachers and content
workshops for journalists.
SDO Teams Meeting
42
Author: R Burston, L Gizon, Y Saidi
Institution: Max-Planck-Institut für Sonnensystemforschung
Email: burston@mps.mpg.de
Poster Title:
German Data Center for the Solar Dynamics Observatory
Abstract:
The German Data Center (GDC) for the Solar Dynamics Observatory (SDO),
hosted by the Max Planck Institute for Solar System Research, will
provide SDO data access to the German solar physics community. The GDCSDO will make available all the relevant HMI data for helioseismology
and smaller selected AIA data sets. This project is funded by the
German Aerospace Center (DLR) until 2012.
An important component of the GDC-SDO is the Data Record Management
System (DRMS), developed and distributed by the Stanford/Lockheed Joint
Science Operations Center (JSOC). The DRMS is currently fully
operational at the GDC-SDO. Efforts are underway to design a GDC-SDO
data processing pipeline. The GDC-SDO hardware will comprise 2x 16 CPU
core machines to run the DRMS software and deliver rapid searches
through a PostgreSQL database, a 16 CPU core machine for preprocessing
the data, and 3x 48 TB hard disks for storage, which all communicates
over a fast InfiniBand network. A 160 TB tape library/robot will
provide near-line data storage. Additional information about the GDCSDO can be found at
http://www.mps.mpg.de/projects/seismo/GDC1/index.html.
SDO Teams Meeting
43
Author: O. Burtseva and F. Hill
Institution: NSO/GONG, 950 N. Cherry Ave., Tucson, AZ 85719
Email: burtseva@noao.edu
Poster Title:
Lifetimes of high-l solar p-modes: effect of surface activity
Abstract:
We study effect of surface activity on measurements of lifetimes of
high-l solar p-modes with SOHO/MDI data using time-distance technique.
Active regions were masked out and lifetimes with and without masking
of active regions were compared. Obtained results will be discussed.
SDO Teams Meeting
44
Author: B.W. Caplins (1), D.A.N. Mueller (1), J. Ireland (2),
G.Dimitoglou (1), B. Fleck (1)
Institution: (1) European Space Agency at NASA GSFC, (2) ADNET Systems
at NASA GSFC
Email: dmueller@esa.nascom.nasa.gov
Poster Title:
J HelioViewer -
A JPEG 2000 Solar Image Browser
Abstract:
We present a prototype of a novel solar data browser geared towards
SDO's AIA data. It is based on the JPEG 2000 compression standard for
highly efficient browsing in time and space. Our approach is both
flexible, scalable and platform-independent. The random code stream
access of the JPEG 2000 interactive protocol minimizes data transfer
and can encapsulate meta data as well as multiple spectral channels in
one data stream. This approach is therefore perfectly suited for
dealing with the large volume of AIA data.
We present progress made in developing the required technologies to
enable the various interacting components of J HelioViewer. We discuss
the synergy and eventual merging with the tile-based HelioViewer (see
poster of J. Ireland et al.) and the feasibility of making the full
SOHO and SDO science data catalogs intuitively browsable with this new
tool.
SDO Teams Meeting
45
Author: Phillip C. Chamberlin, Thomas N. Woods, Francis G. Eparvier
Institution: LASP/U. of Colorado
Email: phil.chamberlin@lasp.colorado.edu
Poster Title:
SDO EVE Contributions and Improvements to the Flare Irradiance Spectral
Model (FISM)
Abstract:
The Flare Irradiance Spectral Model (FISM) is a model of the solar
spectral irradiance from 0.1-190 nm with a temporal resolution of 1minute. FISM daily values are currently based on measurements from
TIMED SEE, UARS SOLSTICE, and SORCE XPS. SDO EVE will provide daily
measurements of the solar XUV and EUV (0.1-105 nm), as well as Lyman
Alpha (121.6 nm), at a much higher accuracy and spectral resolution,
especially below 27 nm, than these aforementioned measurements. EVE
will allow FISM to make more accurate irradiance estimations, and will
also allow FISM to improve its spectral resolution to 0.1nm. The FISM
flare estimations are currently based only on 39 flares at various
stages in the flare evolution from TIMED SEE and SORCE XPS. SDO EVE,
with its ~100% duty cycle, will observe a large number of flares during
solar cycle 24, and will observe the entire evolution of the flares
concurrently at all wavelengths. Therefore, SDO EVE will also help
lower the uncertainties of the FISM flare estimations. FISM will also
be updated to use the SDO EVE space weather product as its proxies,
which will also provide more representative, multiple wavelength flare
proxies besides the GOES XRS and its derivative.
SDO Teams Meeting
46
Author: Sebastien Couvidat
Institution: HEPL, Stanford University
Email: couvidat@stanford.edu
Poster Title:
Thermal or Magnetic Origin of the Sound-Speed Perturbations Below
Sunspots?
Abstract:
We apply the time-distance formalism on Doppler velocity data of 12
solar active regions observed by SOHO/MDI between 1997 and 2006.
Maps of the travel-time perturbations of acoustic waves are produced
for 36 distances between source and receiver, and inverted for soundspeed perturbations below the solar surface down to 26.8 Mm.
The well-known two-region subsurface structure of a sunspot (a shallow
region of decrease in sound-speed immediately below the surface
followed by a region of increase in sound-speed deeper inside the Sun)
is observed for every active region. We observe strong relations
between surface line-of-sight magnetic flux, surface umbral
temperature, and amplitudes of the sound-speed perturbation below the
surface and transition depth between the two regions. These relations
are used to comment on the hypotheses that the two-region structure is
a thermal effect or a magnetic one.
SDO Teams Meeting
47
Author: Ashley Crouch, Graham Barnes, KD Leka
Institution: NWRA/CoRA
Email: ash@cora.nwra.com
Poster Title:
Ambiguity Resolution for the HMI Pipeline
Abstract:
We will give a status report on the tools that will be used to
disambiguate the vector magnetogram data produced by the HMI pipeline.
These are based on one of the best available methods for single height
data and involve the global minimization of the "energy" over the field
of view (here "energy" is a combination of the current and the
divergence of the field). We test these methods on artificial data for
active region patches and full-disk.
SDO Teams Meeting
48
Author: J.L. Culhane, E.C. Auden, Y. P. Elsworth, A. Fludra, M.
Thompson
Institution: Mullard Space Science Laboratory, University College
London,
Email: jlc@mssl.ucl.ac.uk
Poster Title:
eSDO: Algorithms, Visualization Movie Tool, and AstroGrid Data
Integration
Abstract:
The UK-based SDO e-Science consortium has been funded by PPARC, now
STFC, as a three year project to work with US SDO investigation teams
to extract data products and enable data access by the UK Solar Physics
community. Following a year of research into meeting the UK solar
community’s needs through algorithms, data centre access and
visualization tools, two years of eSDO development and implementation
began in October, 2005. For more details, please visit
http://www.mssl.ucl.ac.uk/twiki/bin/view/SDO.
The final project report and all code will be available from 1 October
2007 at http://www.mssl.ucl.ac.uk/twiki/bin/view/FinalDeliverables.
SDO Teams Meeting
49
Author: I. De Moortel (1), S.J. Bradshaw (2)
Institution: (1) School of Mathematics and Statistics, University of St
Andrews, UK; (2) Space and Atmospheric Physics Department, Imperial
College London, UK
Email: ineke@mcs.st-and.ac.uk
Poster Title:
Estimating Damping Rates of Intensity Oscillations Observed with
AIA/SDO
Abstract:
Forward modelling is used to investigate the relation between given
temperature and density perturbations and the resulting (synthesised)
intensity perturbations. Complex and highly non-linear interactions
between the components which make up the intensity (density, ionisation
balance and emissivity) mean that it is non-trivial to reverse this
process, i.e. obtain the density and temperature perturbations
associated with observed intensity oscillations. In particular, it is
found that the damping rate does not often 'survive' the forward
modelling process, highlighting the need for a very careful
interpretation of observed (intensity) damping rates. Although we use
TRACE intensity oscillations as an example, the same effects are likely
to be present in observations made by AIA/SDO.
SDO Teams Meeting
50
Author: J. de Patoul, B. Nicula, J.M. Krijger, D. Bergmans, O.
Podladchikova, S. Willems, B. Inhester, T. Wigelman, M. Kretzschmar
Institution: SIDC, Royal Observatory of Belgium ; Max Planck Institute
for Solar System Research, Germany ; LPCE/CNRS Université d'Orleans,
France
Email: krijger@sidc.be
Poster Title:
SOFLEX, SOlar FLare EXtractor
Abstract:
The SOlar FLare EXtractor (SOFLEX) is built in order to study flare
events: to have a better understanding of the time profile of the event
itself in different wavelengths and to have the full understanding of
the behaviors of the flares through the solar cycle. In the first hand
SOFLEX is a software package able to detect EUV flares in EUV data
images, such as available from EIT and STEREO and soon SDO, with its
principal characteristics. In the second hand, it allows of improving
significantly our understanding of EUV flares phenomena with respect to
better studied X-ray flaring processes.
SDO Teams Meeting
51
Author: B. De Pontieu [1], S. McIntosh [2], V. Hansteen [3,1], M.
Carlsson [3], T. Tarbell [1]
Institution: [1] LMSAL, [2] HAO, [3] University of Oslo
Email: bdp@lmsal.com
Poster Title:
Hinode and the Corona's lower boundary: Spicules and Alfven Waves
Abstract:
Recently, observations with the Solar Optical Telescope (SOT) onboard
Hinode and ground-based telescopes combined with advanced numerical
simulations have provided us with unprecedented views and a better
understanding of the dynamics of the chromosphere and how the lower
boundary couples to the corona and solar wind.
We provide an overview of these results, with a focus on spicules and
Alfven waves and the implications for SDO observations. We show that
the dynamics of the magnetized chromosphere are dominated by at least
two different types of spicules -- dynamic jets of plasma that shoot
upward at velocities of order 20-150 km/s. We show that the first
type involves up- and downward motion that is driven by shock waves
that form when global oscillations and convective flows leak into the
chromosphere along magnetic field lines on on 3-7 minute
timescales. The second type of spicules is much more dynamic, forming
on timescales of 10s, and is most likely formed as a consequence of
magnetic reconnection, and may have a significant impact on the
coronal energy balance.
Our analysis of Hinode data also indicates that the chromosphere is
permeated by strong Alfven waves. Both types of spicules are observed
to carry these Alfven waves, which have significant amplitudes of
order 20 km/s, transverse displacements of order 500-1,000 km and
periods of 150-400 s. Estimates of the energy flux carried by these
Alfven waves and comparisons to advanced radiative MHD simulations
indicate that these waves most likely play a significant role in the
acceleration of the solar wind. We will discuss the implications of
these waves on the energy balance of the lower atmosphere.
SDO Teams Meeting
52
Author: DeForest, C.E.
Institution: SwRI
Email: deforest@boulder.swri.edu
Poster Title:
The Importance of Scattering and Deconvolution in EUV Observations
Abstract:
I have estimated the TRACE PSF scattering wings in the 171 A channel
using the Venus occultation data. The results, and their effect on
TRACE images, are surprising. I conclude that stray light analysis
using the lunar limb or other external occulter will be important for
correct interpretation of AIA images.
SDO Teams Meeting
53
Author: Ed Deluca, R. Bruce Ward, and Mary Liscombe
Institution: Harvard-Smithsonian Center for Astrophysics and the
Christa McAuliffe Challenger Learning Center (Framingham, MA)
Email: bward@cfa.harvard.edu
Poster Title:
Integrating a Space-Weather Station into Challenger Learning Center
Space Flight Simulations
Abstract:
The Harvard-Smithsonian Center for Astrophysics and the Christa
McAuliffe Challenger Learning Center in Framingham, MA, have created
discovery-based space-weather activities, both for use with student or
general audiences, and particularly for those planning to take part in
a mission simulation at a Challenger Learning Center (CLC). The
simulation includes features related to effects the Sun could have on
manned space missions. Currently both the CLC simulation scenarios for
Return to the Moon and Voyage to Mars include a space-weather
component.
SDO Teams Meeting
54
Author: Leonid Didkovsky, Darrell Judge, and Seth Wieman
Institution: Space Sciences Center, University of Southern California,
Los Angeles, USA
Email: leonid@usc.edu
Poster Title:
Completely Restored Bastille Day Solar Flare EUV (26-34 nm) Profile
from SOHO/CELIAS/SEM Measurements Using a New High Fidelity Restoration
Algorithm
Abstract:
High-energy particles affect EUV measurements during strong solar flare
events by significantly increasing the Particle Background Signal
(PBS), and may exceed the measured EUV peak of the flare by more than
an order of magnitude, and last tens of hours. SEM EUV measurements of
the Bastille Day (BD) solar flare (July 14, 2000) in the first order
channels (26 – 34 nm) were substantially contaminated by the PBS. A
previous PBS restoration algorithm for the SEM first order channel data
was based on using the GOES XL (0.1 – 0.8 nm) profile to approximate
the post flare variability of the SEM EUV flux. That algorithm included
some uncertainty due to different (and unknown) spectral variability in
the EUV band-pass. Here we propose a new restoration algorithm for
removing the PBS based on using the different particle response of the
two SEM first order channels as an internal, accurate, particle
reference signal, for the SEM data analysis. This new algorithm allows
us to obtain a significantly improved, full restoration of the BD solar
flare EUV (26 – 34 nm) profile, and will be used to remove the PBS from
other strong solar flare event measurements.
SDO Teams Meeting
55
Author: Emilie Drobnes
Institution: ADNET Systems, inc./NASA GSFC
Email: emilie.drobnes@nasa.gov
Poster Title:
Family Science Night: Changing Perceptions one Family at a Time
Abstract:
The NASA Goddard Space Flight Center Family Science Night program
invites middle school students and their families to explore the
importance of science and technology in our daily lives by providing a
venue for families to comfortably engage in learning activities that
change their perception and understanding of science - making it more
practical and approachable for participants of all ages.
The Family Science Night program runs a monthly two-hour event
throughout the academic year at the Goddard Visitor Center. Unlike
most youth science programs, this is an event where the entire family
must participate in all activities. Family Science Night strives to
change the way that students and their families participate in science,
within the program and beyond.
SDO Teams Meeting
56
Author: Emilie Drobnes
Institution: ADNET Systems, inc./NASA GSFC
Email: emilie.drobnes@nasa.gov
Poster Title:
The Sunday Experiment
Abstract:
Science is part of our daily lives. Through hands-on science activities
and one-on-one interaction with scientists, engineers and Education and
Public Outreach professionals, we can change attitudes toward science
as well as inform the general public about the great work that is being
done at Goddard Space Flight Center. Community members generally do not
realize the role science plays in our every day lives. They may think
science is too complicated to understand, not realizing that science is
everywhere and in everything we do. The Sunday Experiment aims to make
science and engineering more approachable and fun so that visitors feel
more comfortable being engaged ins science activities, ultimately
improving their perception of science, technology, engineering and
math.
SDO Teams Meeting
57
Author: George H. Fisher, Brian T. Welsch, William P. Abbett, David J.
Bercik
Institution: Space Sciences Lab, UC Berkeley
Email: fisher@ssl.berkeley.edu
Poster Title:
A New Technique for Finding Electric Fields from Sequences of Vector
Magnetograms
Abstract:
The advent of extensive ground-based and space-based vector magnetogram
data will greatly improve our quantitative understanding of how
magnetic fields evolve in the solar atmosphere. A problem of current
interest is the derivation of electric fields or velocity fields from
vector magnetogram data, as this is the crucial link between
observation and future physics-based time-dependent models of the solar
atmosphere.
Most previous techniques for deriving E or v have used only the normal
component of the magnetic induction equation, as it is generally
believed that depth derivatives contained in the magnetic induction
equation cannot be derived from vector measurements taken within a
single layer.
We will show that in fact, sufficient information exists within a
sequence of vector magnetograms to determine a 3-dimensional electric
field whose curl reproduces the observed changes in all 3 components of
B. While this is certainly a major step forward, it is also true that
the electric field E itself, as opposed to its curl, is underconstrained by the data. We will discuss how additional constraints may
be used to uniquely determine all 3 components of the electric field.
SDO Teams Meeting
58
Author: Manolis K. Georgoulis
Institution: JHU/APL
Email: manolis.georgoulis@jhuapl.edu
Poster Title:
ARIA and NPFC: Automatic Active Region Identification and Azimuth
Disambiguation Methods for the SDO/HMI Full-Disk Vector Magnetograms
Abstract:
The Non-Potential magnetic Field Calculation (NPFC) method is proposed
for the automatic azimuth disambiguation of the vector magnetograms to
be acquired by the Helioseismic and Magnetic Imager (HMI) on board the
Solar Dynamics Observatory (SDO). The NPFC method relies on firm
physical grounds and has been tested extensively on data from various
magnetographs. It was concluded that the NPFC method exhibits strong
insensitivity to noise, accuracy, stability, and automatic
functionality, all combined with remarkable computational speed. For
the above, it is the method of choice for the disambiguation of the
full-disk vector magnetograms acquired by the Vector
Spectromagnetograph (VSM) of the NSO's SOLIS facility. While the NPFC
method was originally conceived for azimuth disambiguation of activeregion fields and is accompanied by an Active Region Identification
Algorithm (ARIA) that allows to automatically pick up active regions
from the solar disk, recent efforts suggest that it can be used just as
effectively for full-disk disambiguation in SOLIS/VSM data, following a
proper geometrical partitioning of the solar disk in individual tiles.
Given the unprecedented ability of both SOLIS/VSM and SDO/HMI
magnetograms to capture the magnetic field vector in the entire visible
solar disk, we are confident that the ARIA/NPFC package will serve the
best interests of SDO/HMI, as well, and will provide the user community
with the state-of-the-art full- and partial-disk magnetic field
solutions for further scientific applications.
SDO Teams Meeting
59
Author: Sarah Gibson
Institution: NCAR/HAO
Email: sgibson@ucar.edu
Poster Title:
Space weather implications of partially-ejected flux ropes
Abstract:
The structure and evolution at the source of solar activity directly
affects the nature of the space weather disturbance that reaches the
Earth. We employ a three-dimensional numerical magnetohydrodynamic
simulation of a coronal mass ejection (CME) to show how, in the course
of its eruption, a coronal flux rope may writhe and reconnect both
internally and with surrounding fields in a manner that alters its
magnetic connectivity, helicity, orientation, and topology.
Moreover,
because the rope breaks in two during eruption, the surviving portion
of the rope is a candidate for future eruptions. These changes would
complicate how interplanetary CME (ICMEs) embedded in the solar wind
relate to their solar source. In particular, the location and
evolution of transient coronal holes, topology of magnetic clouds
(``tethered spheromak''), and likelihood of interacting ICMEs would
differ significantly from what would be predicted for a CME which did
not undergo writhing and partial ejection during eruption.
SDO Teams Meeting
60
Author: S. Gissot, J.-F. Hochedez, J.M.Krijger
Institution: SIDC, Royal Observatory of Belgium
Email: krijger@sidc.be
Poster Title:
Velociraptor, a motion estimation algorithm analyzing the dynamics in
EUV movies of the solar atmosphere
Abstract:
Velociraptor is a multiscale motion estimation algorithm able to
estimate simultaneously the apparent motion vector and the variation in
brightness from two successive frames in a sequence of solar EUV
images.
Here, we extend our motion analysis tool to the SDO multi-wavelength
capabilities. The objective is to monitor the multi-wavelength
evolution of the solar atmospheric plasma, including e.g. oscillation
analyses of the loop systems in active regions, or trackings of
erupting filaments. Because of the rapid evolution of solar atmospheric
features, as observed in the TRACE data, we propose to apply the
Velociraptor processing algorithm on SDO high-cadence and multiwavelength data. Using the brightness variation maps, it also permits
the identification and the quantification of multi-wavelength intensity
variations, and can be applied to precise flare detection and
localization, as well as to dimming identification such as transient
coronal holes.
SDO Teams Meeting
61
Author: Mandy Hagenaar, Marc DeRosa, and Karel Schrijver
Institution: Lockheed Martin Solar and Astrophysics Laboratory
Email: hagenaar@lmsal.com
Poster Title:
The Dependence of Ephemeral Region Emergence on local Flux Imbalance
Abstract:
We investigate the distribution and evolution of existing and emerging
magnetic network elements in the quiet-Sun photosphere. The ephemeral
region emergence rate is found to depend primarily on the imbalance of
magnetic flux in the area surrounding its emergence location, such that
the rate of flux emergence is lower within strongly unipolar regions by
at least a factor of three relative to flux-balanced quiet Sun. As
coronal holes occur over unipolar regions, this also means that
ephemeral regions occur less frequently there, but we show that this is
an indirect effect - independent of whether the region is located
within an open-field coronal hole or a closed-field quiet region. We
discuss the implications of this finding for near-photospheric dynamo
action and for the coupling between closed coronal and open
heliospheric fields.
SDO Teams Meeting
62
Author: Hanasoge, S. M. & Larson, T. P.
Institution: W. W. Hansen Experimental Physics Laboratory, Stanford
University, CA 94305
Email: shravan@stanford.edu
Poster Title:
Global effects of local sound-speed perturbations in the Sun: A
theoretical study
Abstract:
We study the effect of localized sound-speed perturbations on global
mode frequencies by applying techniques of global helioseismology on
numerical simulations of the solar acoustic wave field. Extending the
method of realization noise subtraction (e.g. Hanasoge et al. 2007) to
global modes and exploiting the luxury of full spherical coverage, we
are able to achieve very highly resolved frequency differences that are
used to study sensitivities and the signatures of the thermal
asphericities. We find that (1) global modes are almost twice as
sensitive to sound-speed perturbations at the bottom of the convection
zone as in comparison to anomalies well in the radiative interior
($r\lesssim0.55 R_\odot$), (2) the $m$-degeneracy is lifted ever so
slightly, as seen in the $a$ coefficients, and (3) modes that propagate
in the vicinity of the perturbations show small amplitude shifts ($\sim
0.5\%$).
SDO Teams Meeting
63
Author: Thomas Hartlep1, Junwei Zhao2, Nagi N. Mansour1, Alexander G.
Kosovichev2
Institution: ^1 NASA Ames Research Center, Moffett Field, CA; ^2 W.W.
Hansen Experimental Physics Laboratory, Stanford University, CA
Email: thomas.hartlep@nasa.gov
Poster Title:
Validation of Far-Side Imaging of Solar Active Regions through
Numerical Simulations
Abstract:
Helioseismology provides important tools for understanding the solar
interior as well as for space weather forecasting. Using observation
data from instruments such as MDI (Michelson Doppler Imager) aboard the
SOHO (Solar and Heliospheric Observatory) spacecraft, helioseismic
inferences have tremendously advanced our knowledge and understanding
of the interior structure and dynamics of the Sun. In general, the
methods used for analyzing observations are based on simplified models
of wave propagation such as ray or Born approximation, but have not
been validated by more sophisticated models or numerical simulations.
Here, we evaluate one technique, far-side imaging of solar active
region by time-distance helioseismology, by using artificial
oscillation data derived from numerical simulations of wave propagation
in the Sun. The simulations are performed for the full spherical Sun.
Active regions are modeled by locally modifying the speed of sound. We
evaluate the performance of the far-side imaging technique by varying
the size and location of the artificial active region, and analyze the
appearance of ghost images and artifacts.
This research is supported by NASA's Living with a Star program. The
support of the NASA Postdoctoral Program administered by Oak Ridge
Associated Universities is gratefully acknowledged. Simulations have
been performed on the Columbia Supercomputer at NASA Ames Research
Center.
SDO Teams Meeting
64
Author: Keiji Hayashi
Institution: HEPL, Stanford University
Email: keiji@sun.stanford.edu
Poster Title:
MHD simulation of the solar corona using the daily-updated solar
surface magnetic field data in synoptic chart
Abstract:
We will present the MHD simulation of the global solar corona using the
daily-updated synoptic map of the solar surface magnetic field. The
presented simulation uses the SOHO/MDI EOF data and can be regularly
conducted on daily basis. The simulation results are displayed on the
public-accessible web site.
SDO Teams Meeting
65
Author: HMI Calibration Team
Institution: Stanford University and other places
Email: schou@sun.stanford.edu
Poster Title:
HMI Calibration and Performance
Abstract:
We have recently finished the ground based calibration of the HMI
instrument.
In this poster we will describe some of the calibrations performed and
show selected results.
We will also briefly discuss the on-orbit calibrations
and the expected performance of the instrument.
SDO Teams Meeting
66
Author: Rachel A. Hock, Francis G. Eparvier
Institution: LASP, University of Colorado
Email: rachel.hock@lasp.colorado.edu
Poster Title:
Cross-Calibration of SOHO-EIT and TIMED-SEE Irradiances
Abstract:
Absolutely calibrated solar images are necessary for a variety of solar
physics problems, such as the identification of solar variability
sources and the derivation of differential emission measure (DEM) maps.
SOHO-EIT is absolutely calibrated using TIMED-SEE spectra to provide a
method of determining physical values of irradiance for EIT images.
EIT images from 1 April 2002 to 15 March 2005 in the 28.4 nm and 30.4
nm channels are compared to SEE daily spectra from the same time
period. The resulting fitted EIT irradiances are well correlated to
SEE irradiance measurements and are within the uncertainties of both
instruments. The new cross-calibration results are compared to the
currently used calibration based on UARS-SUSIM Mg II Index.
SDO Teams Meeting
67
Author: J. Todd Hoeksema & The HMI Magnetic Team
Institution: Stanford University and Elsewhere
Email: todd@sun.stanford.edu
Poster Title:
The HMI Magnetic Field Measurement Program
Abstract:
The Helioseismic and Magnetic Imager (HMI) instrument on the Solar
Dynamics Observatory (SDO) spacecraft will begin observing the solar
photospheric magnetic field continuously after commissioning in early
2009. This paper describes the HMI magnetic processing pipeline and the
expected data products that will be available. The full disk line-ofsight magnetic field will be available every minute with 1" resolution.
Comparable vector measurements collected over a three-minute time
interval will ordinarily be averaged for at least 10 minutes before
inversion. Useful Quick Look products for forecasting purposes will be
available a few minutes after observation. Final products will be
computed within 36 hours and made available through the SDO Joint
Science Operations Center (JSOC). Three kinds of magnetic data
products have been defined - standard, on-demand, and on-request.
Standard products, such as frequently updated synoptic charts, are made
all the time on a fixed cadence. On-demand products, such as high
cadence full-disk disambiguated vector magnetograms, will be generated
whenever a user asks for them. On-request products, such as highresolution time series of MHD model solutions, will be generated as
resources allow. This paper describes the observations, magnetograms,
synoptic and synchronic products, and field model calculations that
will be produced by the HMI magnetic pipeline.
SDO Teams Meeting
68
Author: R. Howe (1), F. Hill (1), R. W. Komm (1), J. Schou (2), M. J.
Thompson (3)
Institution: (1) National Solar Observatory (2) Stanford University (3)
University of Sheffield
Email: rhowe@noao.edu
Poster Title:
Rotation and Zonal Flows in Global Helioseismology: Merging Data Sets
Abstract:
During solar cycle 23, MDI and GONG have both provided near-continuous
monitoring of the solar rotation and its temporal variations, revealing
for example the profile of the migrating zonal flow pattern deep within
the convection zone.
The overlap of HMI with MDI and GONG could be a year or less, after
which HMI could be the only instrument taking near-continuous highresolution helioseismology observations. Continued study of variations
of solar properties, such as the migrating zonal flow bands, over
periods of a solar cycle or more will therefore require the "stitching
together" of data from HMI and MDI/GONG.
We already know that GONG and MDI data have different random and
systematic errors, and those for HMI are likely to be different again.
We will need to act quickly to make the transition between the two
datasets as seamless as possible; therefore, we should start now to
learn how best to do this.
In this poster, we make a start by attempting to find the best way to
combine GONG and MDI data sets.
SDO Teams Meeting
69
Author: J. Ireland(1), M.S. Marsh(2), T. Kucera(3), C. A. Young(1)
Institution: (1) ADNET Systems, Inc., at NASA's GSFC, (2) OURA at
NASA's GSFC. (3) NASA's GSFC
Email: Jack.Ireland@nasa.gov
Poster Title:
Development of an automated oscillation detection algorithm for SDO-AIA
Abstract:
We discuss progress towards the development of an algorithm to
automatically detect oscillating regions in SDO-AIA data. Several
different time series analyses are considered in terms of their
detection rate, false alarm rate and computational speed. We study
their efficacy on test data and on TRACE data, and compare our results
to interactively found oscillations.
SDO Teams Meeting
70
Author: L. Jacoutot, G. Balarac.
Institution: Center for Turbulence Research
Email: jacoutot@stanford.edu
Poster Title:
Evaluation of turbulence models for solar MHD simulations
Abstract:
Direct numerical simulations (DNS) of the realistic Reynolds MHD
turbulent motions are not achievable in many astrophysical simulations
such as for simulations in the convective solar zone. Thus, recent
developments have been made on adapting the large eddy simulation (LES)
method to MHD turbulence. In this work, we have evaluated the
performance of three different magnetic sub-filter models: the
extension of the classic Smagorinsky model, the cross-magnetic-helicity
based model, and a model based on a Taylor series expansion. The three
models have been evaluated a priori using DNS data. From the optimal
estimation theory, we have compared the models with their optimal
estimator (the best possible model for a given set of quantities). It
has been shown that a 'Clark-type' model based on Taylor series
expansions leads to the best results. The models have been compared for
different regimes such as decaying and small-scale dynamo.
SDO Teams Meeting
71
Author: L. Jacoutot 1, A. G. Kosovichev 2, N. N Mansour 3, A. Wray 3
Institution: 1 Stanford University (CTR), 2 Stanford University (HEPL),
3 NASA Ames Research Center
Email: jacoutot@stanford.edu
Poster Title:
Realistic numerical simulations of the upper solar photosphere
Abstract:
The objective of this research is to improve understanding of the
interior structure and dynamics of the sun by means of realistic
numerical simulation. This investigation is carried out in
collaboration with Stanford Solar Physics and NASA Ames Research
Center. The goal of this research is to investigate how well various
turbulence models can describe the physical properties of the upper
convective boundary layer of the Sun. We have carried out realistic
numerical simulations using a hyperviscosity approach and various
physical Large-Eddy Simulation (LES) models (Smagorinsky and dynamic
models) to investigate how the differences in turbulence modeling
affect the damping and excitation of the oscillations and their
spectral properties and to compare with observations.
SDO Teams Meeting
72
Author: Joey Shapiro Key, Adam Kobelski, Tyson B. Littenberg, David E.
McKenzie
Institution: Montana State University
Email: mckenzie@solar.physics.montana.edu
Poster Title:
The Space Public Outreach Team (SPOT):
Bringing Current NASA Missions to Montana K-12 Classrooms
Abstract:
The Space Public Outreach Team at Montana State University and the
University of Montana provides free presentations about current NASA
science to classrooms across the state of Montana. Undergraduate
presenters from a variety of majors are trained by MSU Physics graduate
students to give 45 minute interactive presentations. The SPOT program
has reached over 10,000 students in Montana already this academic year,
at the low cost of about $4 per student. The SPOT model is easily
exportable to other institutions, and a package of start-up material is
offered by the current SPOT managers.
SDO Teams Meeting
73
Author: E. Khomenko (1,2), K. Parchevsky (3), M. Collados (1), A.
Kosovichev (3) and V. Olshevsky (2)
Institution: (1) Instituto de Astrofisica de Canarias, 38205, Spain;
(2) Main Astronomical Observatory, 03680, Ukraine; (3) Stanford
University, CA 94305, United States
Email: khomenko@iac.es
Poster Title:
Numerical simulations of waves in a sunspot model
Abstract:
We present numerical simulations of magneto-acoustic wave propagation
in a magnetic sunspot-like structure. A thick flux tube, with
dimensions typical of a small sunspot, is perturbed by a vertical or
horizontal velocity pulse at photospheric level. Two cases are
considered: (i) the waves sources are located inside the sunspot and
(ii) the wave sources are located outside the sunspot in the weakly
magnetized atmosphere. The type of modes generated depends on the
location and type of the acoustic source. Mode conversion is observed
to occur in the region where both characteristic speeds have similar
values. We calculate the time-distance and amplitude characteristics of
wave propagation, and compare with helioseismic measurements.
SDO Teams Meeting
74
Author: Shukur Kholikov
Institution: NSO/GONG
Email: kholikov@noao.edu
Poster Title:
GONG Time Distance Pipeline
Abstract:
We describe GONG time distance pipeline structure.
Some key points and preliminary results will be presented.
SDO Teams Meeting
75
Author: I.N. Kitiashvili and A.G. Kosovichev
Institution: Center for Turbulence Research and HEPL, Stanford
University
Email: irinasun@stanford.edu
Poster Title:
Dynamical Models of Solar Dynamo and Data Assimilation Methods
Abstract:
Dynamical models which provide a simple description of non-linear
behaviour of the solar dynamo are important for investigating the
relationship between the basic physical parameters (e.g. rotation rate
and helicity) and the cyclic and stochastic properties of the systems.
The main properties of the dynamo systems are investigated by using
qualitative methods of dynamical systems and numerical solutions. In
addition, the data assimilation methods developed in meteorology and
Earth science makes possible efficient and accurate estimations of
physical properties, which cannot be observed directly.
SDO Teams Meeting
76
Author: Michael Kirk; Dean Pesnell
Institution: Adnet Systems, NASA GSFC; NASA GSFC
Email: michael.s.kirk@gmail.com
Poster Title:
Automatic Detection of Polar Coronal Holes in the EUV
Abstract:
A new method for automatically detecting and measuring Polar Coronal
Holes in the EUV is presented. We use a series of full solar disk
images over solar cycle 23 to measure the perimeter of polar coronal
holes as they appear on the limbs. This method utilizes 171, 195, and
304 Å solar images from the Extreme ultraviolet Imaging Telescope (EIT)
on SOHO. We are able to more accurately define the size and shape of
the polar hole by taking measurements on the limb and making two
measurements per image rather than the one used to construct synoptic
maps. This method also minimizes line-of-sight obscurations caused by
the emitting plasma of the various wavelengths. Perimeter tracking
allows for the polar coronal rotation period to emerge organically from
the data as 33 days. We have called this the Harvey Rotation rate and
count Harvey Rotations starting July 1, 1989. From the measured
perimeter we are then able to fit a curve to the data and derive an
area within the line of best fit. This method should help to improve
our estimates of the size and location of polar coronal holes.
SDO Teams Meeting
77
Author: S.G. Korzennik (1) and A. Eff-Darwich (2,3)
Institution: (1) Harvard-Smithsonian Center for Astrophysics,
Cambridge, MA; (2) Dpto. Edafologia y Geologia, (3) Instituto de
Astrofisica de Canarias, Tenerife, Spain
Email: skorzennik@cfa.harvard.edu
Poster Title:
On the dependence of our inferences about the solar internal rotation
with the frequency splittings fitting methodology
Abstract:
We present how inferences of the solar internal rotation rate depends
on different aspects of the peak fitting procedure. The stability with
time of the rotation rate is studied through inversions of frequency
splittings datasets computed from fitting 364, 728 and 2088-day long
MDI time series. In particular, we attempt to assess the extent of the
solar torsional oscillations to the deepest layers of the convection
zone and the radiative zone.
The frequency splittings obtained from the 2088-day long MDI timeseries through two different fitting techniques are also inverted to
analyze the effect of the fitting methodology on the inferred rotation
rate. In particular, we present inversions based on either individual
frequencies (as derived by the fitting technique developed by Korzennik
2005), or frequency splittings parametrized in terms of Clebsh-Gordon
(CG) coefficients. The effect of using either CG or individual
frequencies to estimate the rotational splittings is studied in details
through its effect on the inversion results.
SDO Teams Meeting
78
Author: Sylvain Korzennik
Institution: Harvard-Smithsonian Center for Astrophysics
Email: skorzennik@cfa.harvard.edu
Poster Title:
Results from fitting long and very-long MDI time series of spherical
harmonics coefficients, at low and intermediate degrees.
Abstract:
I present results from fitting long and very-long MDI time series of
spherical harmonics coefficients, at low and intermediate degrees. The
fitting methodology used, initially developed for very-long time
series, incorporates several key aspects not present in the
"production" MDI (or GONG) fitting methodologies. The fitting has since
been extended to higher degrees and applied to shorter time series.
I present results from fitting 20088-day long, as well as, 728, 364
and182-day long time series, covering nearly 11 years of observations.
The 2088-day long time series has been fitting up to l=120. Nine
overlapping 728-day long time series have been fitted up to l=95, while
nineteen and thirty nine overlapping 364 and 182-day long time series,
respectively, have been fitted up to l=47.
I present and discuss remaining "issues" with the fitting, namely
fitting at very low frequencies, leakage mismatch, and a careful
assessment of the error bar estimates. I also present inferred results
for rotation and sound speed and some of the characteristics of the
observed temporal changes.
SDO Teams Meeting
79
Author: A.G. Kosovichev and HMI Science Team
Institution: Stanford University
Email: sasha@sun.stanford.edu
Poster Title:
Helioseismology Program for Solar Dynamics Observatory
Abstract:
The Helioseismic and Magnetic Imager (HMI) investigation encompasses
three primary objectives of the Living With a Star Program: first, to
determine how and why the Sun varies; second, to improve our
understanding of how the Sun drives global change and space weather;
and third, to determine to what extent predictions of space weather and
global change can be made and to prototype predictive techniques.
Helioseismology provides unique tools to study the basic mechanisms of
the Sun's magnetic activity and variability. It plays a crucial role in
all HMI investigations, which include convection-zone dynamics and the
solar dynamo; origin and evolution of sunspots, active regions and
complexes of activity; sources and drivers of solar activity and
disturbances; links between the internal processes and dynamics of the
corona and heliosphere; and precursors of solar disturbances for spaceweather forecasts.
HMI will open new opportunities for helioseismology studies, in
combination with data from the other SDO instruments, Atmospheric
Imaging Assembly (AIA) and Extreme-ultraviolet Variability Experiment
(EVE), and also from various space and ground-based observatories.
SDO Teams Meeting
80
Author: Masahito Kubo
Institution: High Altitude Observatory, National Center for Atmospheric
Research
Email: kubo@ucar.edu
Poster Title:
Disintegration of Magnetic Flux in Decaying Sunspots
Abstract:
Recent Hinode observations reveal that convective motions around
the penumbral outer boundary are related to disintegration of
magnetic flux in the decaying sunspot.
The penumbral spines, which have stronger and more vertical magnetic
fields than their surroundings, elongate toward the moat region
in concert with outward motions of penumbral bright features.
Granule-like structures appear one after another in the outer penumbra
while moving magnetic features (MMFs) are separating from the penumbral
spines.
It was also found that the detachment of such MMFs from the penumbral
spines
are often observed in the neighborhood of the elongating dark penumbral
filaments, which are associated with Evershed flows.
These results suggest that investigation of convection motions in and
below
the sunspots is crucial for understanding of the decay of sunspots.
SDO Teams Meeting
81
Author: D. A. Lamb; C. E. DeForest
Institution: University of Colorado; Southwest Research Institute
Email: Derek.Lamb@colorado.edu
Poster Title:
Magnetic Flux Emergence Around Network Concentrations
Abstract:
The presence of a magnetic guide field may alter the local dynamo
process near the solar surface in one of two ways. Areas of strong
field may suppress dynamo action by modifying the turbulent convective
flows, resulting in reduced magnetic flux emergence. Conversely, these
guide fields may enhance dynamo action by providing additional field
that is stretched and brought up to the surface, resulting in increased
flux emergence. Hypothesizing that network concentrations provide a
guide field on spatial scales much smaller than a coronal hole, we
analyze the emergence pattern around several network concentrations
observed in Hinode NFI magnetograms. We determine if flux emergence
around network concentrations is altered in the form of a suppression
or an enhancement.
SDO Teams Meeting
82
Author: Larson, T P and Schou, J
Institution: Stanford University
Email: tplarson@stanford.edu
Poster Title:
Advances in Global Mode Analysis
Abstract:
As with any data analysis, the standard MDI medium-l analysis pipeline
is based on several approximations. Physical effects such as line
asymmetry, horizontal displacement at the solar surface, and distortion
of eigenfunctions have been ignored, as well as cubic distortion in the
optics and instrumental errors in the plate scale and orientation of
the CCD. Furthermore, we see several systematic errors in the results
of the analysis, most notably an annual variation in f-mode frequencies
and a bump in the normalized residuals of the a-coefficients around 3.4
mHz, which may relate to polar jets in the inversions. We have
reprocessed several years of data applying the above corrections, and
made improvements in the pipeline algorithm itself by recomputing the
locations of bad data points and using updated routines for detrending
and gapfilling. Updated values for the mode parameters are now
available for the entire mission. The pipeline has also been almost
entirely automated. Here we discuss the changes in mode parameters
resulting from our improvements and their effect on the magnitude of
systematic errors.
SDO Teams Meeting
83
Author: Robert Leamon
Institution: ADNET Systems Inc./ NASA GSFC
Email: robert.j.leamon@nasa.gov
Poster Title:
SDISPLAY: An EPO Video Wall and Desktop Analysis Tool for SDO.
Abstract:
Part of the Education & Public Outreach (EPO) effort for SDO involves
installing a "video wall." The installation will require six 30"
monitors to display the full 4096x4096 SDO images. It is intended to
first install the system in the atrium of a building at GSFC so that
"anyone" can view the latest results from SDO.
We present a working prototype of the software using the 4 EUV channels
of SOHO/EIT, magnetograms SOHO/MDI and ground-based H-alpha. SDISPLAY
is capable of zooming and panning around a large image, and selecting
either the latest images or from an arbitrary date from the (VSO)
archive.
The software was written using IDL objects, as transparency is only
supported in IDL using object graphics. The superposition of
translucent images is not just an outreach gimmick, but can be a
serious tool for comparing loops in different wavelengths (i.e.,
temperatures), or readily determining which magnetic elements on a
magnetogram the footpoints of a coronal loop tracks to.
SDO Teams Meeting
84
Author: Y. Li, B. J. Lynch, G. Stenborg, J. Luhmann, E. Huttunen, B.
Welsch, P. Liewer, A. Vourlidas
Institution: SSL, NASA, Caltech, NRL
Email: yanli@ssl.berkeley.edu
Poster Title:
The solar eruption from AR10965 on 2007 May 19
Abstract:
The solar eruption on 2007 May 19 from AR10956 (N03W01) was observed by
the STEREO mission, when The twin STEREO spacecraft were at a
separation angle of 8.5˚, within the optimal range for 3D anaglyph
viewing of the corona. We report analysis of the source region
photospheric magnetic field and its pre-eruption evolution using MDI
magnetograms, the source region coronal magnetic field topology
estimated via PFSS modeling, and the observed coronal dynamics of the
eruption through STEREO EUVI wavelet-enhanced anaglyph movies. Despite
its moderate magnitude and size, AR10956 was a complex and highly nonpotential active region with a multipolar configuration. In the two
days prior to the May 19 eruption, the total unsigned magnetic flux of
the region decreased ~17%. We interpret the photospheric magnetic field
evolution, coronal field topology, and the observed coronal dynamics in
the context of current models of CME initiation an
SDO Teams Meeting
85
Author: C. Lindsey
Institution: NorthWest Research Associates; 3380 Mitchell Lane;
Boulder, CO 80301; USA
Email: clindsey@cora.nwra.com
Poster Title:
Simulations of the Near-Surface Interaction Between Waves Magnetic Flux
Tubes
Abstract:
Magnetic fields greatly complicate the problem of modeling of the
thermal structures of active regions beneath their photospheres based
on seismic observations. Magnetic effects involve both refraction and
mode conversion, and are strongly dependent not only on the strength of
the magnetic field but its inclination as well. In linear acoustics, it
is possible, at least in principle, to separate what can be
characterized as the magnetic anomaly from the thermal anomaly, where
the magnetic anomaly is represented by the effects of magnetic forces
and the thermal anomaly represents the effect of the anomalous modulus
of the medium on the incident wave. The problem of how to separate the
two diagnostically is complicated, in general. An important question,
in our opinion, is the influence of the magnetic field on the seismic
signature in response to low-degree seismic waves in regions where the
field is vertical, with the direction of propagation also nominally
vertical. There are strong intuitive arguments to suggest that the
seismic signature at this point is very close to that of a horizontally
uniform, non-magnetic thermal anomaly with the same thermal structure
as that along the vertical magnetic field line. If this is the case,
then the region of nearly vertical field offers an important control
resource for discriminating the thermal anomaly in sunspot umbrae.
Simulations offer the prospect of testing the foregoing hypothesis at
length. The ability of the HMI to provide high-quality Stokes magnetic
observations will be critical to the more general problem of separating
the thermal and magnetic anomalies where the field is significantly
inclined.
SDO Teams Meeting
86
Author: C. Lindsey
Institution: NorthWest Research Associates; 3380 Mitchell Lane;
Boulder, CO 80301; USA
Email: clindsey@cora.nwra.com
Poster Title:
What is the Practicality of a Prompt White-Light Flare Alarm from the
HMI Pipeline?
Abstract:
One of the most important developments in local helioseismology has
been the discovery by Kosivichev & Zharkova of a seismic transient
transmitted into the solar interior by the flare 1996 July 9. This was
signified by outward-propagating surface ripples observed by SOHO/MDI
following the impulsive phase of the flare. Major advances in our
understanding of this phenomenon were made by benefit of supporting
observations from other observing facilities, such as RHESSI, TRACE,
GONG, and ISOON. These have established, among other things, that
seismic emission from flares, when it does occur, generally comes from
the sites of sudden white-light emission, meaning the sudden, compact
component of white-light flares. In a few cases, valuable supporting
observations have come from ground-based facilities that can be
dedicated neither to flares nor to helioseismology on anything like a
full-time basis. It has also been discovered that white-light flares
from which detectable seismic e mission occurs are far more common than
previously thought. These and other developments, not necessarily
related to helioseismology, motivate the question of how useful a
prompt white-light flare alarm would be to the solar community at
large. There are good reasons to project that such an alarm could
inform prospective users of the probable existence and location of a
white-light flare within five minutes of its onset. There are
significant uses for such information even if the white-light flare is
over by the time an observing facility can observe the active region
from which it emanated. Examples include the study of magnetic
evolution of the region in the hour following the flare and possibly
the chemical dynamics of molecular recombination following dissociation
during the flare radiative environment.
SDO Teams Meeting
87
Author: M. McCaffrey, R. Vachon, S. Buhr
Institution: CIRES- CU Boulder
Email: mark.mccaffrey@colorado.edu
Poster Title:
HD for SDO EPO: The Use of High Definition Video for Solar Dynamic
Observatory Education and Public Outreach
Abstract:
The EPO team for the Extreme Ultraviolet Variability Experiment (EVE)
of the Solar Dynamic Observatory mission have been capturing the
development process of the mission in general and experiment in
particular using high definition video technology. We will present some
initial products, including a tour of LASP, interviews with members of
the science team, and examples of how students at Skyline High School
who are English Second Language leaners are learning about solar
dynamics, space weather, the ionosphere and EUV variability. The video
products will be used on websites, in classroom, for teacher
professional development and as virtual tours.
SDO Teams Meeting
88
Author: J.M. McTiernan, B.T. Welsch, G.H. Fisher, D.J. Bercik, W.P.
Abbett
Institution: Space Sciences Lab, University of California
Email: jimm@ssl.berkeley.edu
Poster Title:
Reducing the Divergence of Optimization-Generated Magnetic Fields
Abstract:
Optimization methods (OMs) are often used to extrapolate non-linear,
force-free (NLFF) coronal magnetic fields from measurements of the
vector magnetic field at the Sun's photosphere.
Unfortunately, OM algorithms typically generate a magnetic field that
is not as divergence-free as methods that are explicitly divergencefree (for example, methods that describe the field using a vector
potential).
Here we describe multiple approaches to deriving a correction that can
be added to an arbitrary vector field with a non-zero divergence to
cancel that divergence.
We then apply one technique to OM magnetic fields extrapolated from
magnetograms, within the framework of a particular OM implementation.
We also briefly discuss necessary initial conditions for specifying a
well-posed extrapolation problem.
SDO Teams Meeting
89
Author: Kaori Nagashima(1), Takashi Sekii(1), Alexander G.
Kosovichev(2), Theodore D. Tarbell(3), and Hinode/SOT team
Institution: (1)National Astronomical Observatory of Japan, (2)
Stanford University, (3)Lockheed Martin Solar and Astrophysics
Laboratory
Email: kaorin@solar.mtk.nao.ac.jp
Poster Title:
Initial analyses of non-magnetic Dopplergrams obtained by Hinode/SOT
Abstract:
We report initial analyses of Dopplergrams obtained by the Solar
Optical Telescope (SOT) on Hinode. The Narrowband Filter Imager (NFI)
of SOT provides us with Dopplergrams with 0.2-arcsec spatial resolution
(pixel size 0.16 arcsec) at several wavelengths. Although the field of
view of NFI is limited to 328”x164”, the high resolution enables us to
observe the waves with the spherical harmonic degree l of up to 4000 or
higher. Moreover, using the Fe I 557.6 nm line (Lande g=0), we can take
'non-magnetic' photospheric Dopplergrams. These are not affected by
magnetic field and, therefore, are useful in exploring magnetic
structure, such as sunspots. Various aspects of the non-magnetic
Dopplergrams are examined. We also compare them with the intensity
oscillation data, obtained by the Broadband Filter Imager (BFI) of SOT
and with SOHO/MDI Dopplergrams.
SDO Teams Meeting
90
Author: V.M. Nakariakov
Institution: University of Warwick
Email: V.Nakariakov@warwick.ac.uk
Poster Title:
Coronal Periodmapping
Abstract:
The method of coronal periodmapping, designed for the automated
detection of oscillatory phenomena in imaging time-dependent datasets,
is presented. The method creates a sequence of static 2D maps of the
corona sampled over overlapping time intervals. The colour of each
pixel or a macropixel corresponds to the period of the highest spectral
peak in the time signal of the pixel. The presence of blobs of the same
colour is indicative of a coherent spatially extended oscillatory
process. The application of this technique allows us to produce fast
reduction of imaging dynamical datasets to 2D static maps, which
highlight the regions and times of interest. The coronal periodmapping
technique has been tested on the TRACE, Hinode/XRT and Nobeyama
Radioheliograph datasets.
SDO Teams Meeting
91
Author: Richard W. Nightingale, Alex Ji*, and Stuart Mayo**
Institution: Lockheed Martin Advanced Technology Center, Palo Alto, CA;
*Stanford University, Palo Alto, CA; **University of Berkeley,
Berkeley, CA
Email: nightingale@lmsal.com
Poster Title:
Preliminary Results of a Study of Rotating Sunspots in Active Regions
Utilizing SOHO/MDI Magnetograms During the Solar Maximum in Cycle 23
Abstract:
As part of a statistical study of sunspots that rotate about their
umbral centers in active regions, we have begun to analyze SOHO/MDI
full-disk, synoptic magnetogram movies on a daily basis during solar
maximum in cycle 23. We are analyzing these active regions when they
are least distorted, within approximately ± 30 degrees longitude of
disk center. Many such active regions containing rotating sunspots have
been identified. For example, our preliminary study found such active
regions near disk center with one or more rotating sunspots for
approximately two-thirds of the days in year 2000. Rotating sunspots
result from looking temporally at perpendicular slices of a large,
twisted magnetic flux tube penetrating through the photosphere from
below the solar surface out into the solar corona. The twisted tube, or
loop, carries energy via the Poynting flux density up into the corona,
where some or all of the energy may be stored in the non-potentiality
of the magnetic field to empower flares and coronal mass ejections.
Coupling these findings of the presence of rotating sunspots on a
majority of days during solar maximum with those from previous studies
showing rotating sunspots associated with almost all of the X-flares
since April 1998, and many of the M-flares, suggests that rotating
sunspots could be providing much of the energy needed by the multitude
of large X-ray flares occurring during the solar maximum period.
Preliminary results of this study to date will be presented.
SDO Teams Meeting
92
Author: Clare E. Parnell(1), Craig E. Deforest(2), Hermance J.
Hagenaar(3), Derek Lamb(2)
and Brian Welsch(5)
Institution: (1) Uni. of St Andrews, Scotland, (2)SWRI, Boulder, CO,
(3) LMATC, Palo Alto, CA (4) Uni. of Colorado, Boulder, CO, (5) Uni.
of California, Berkeley, CA
Email: clare@mcs.st-and.ac.uk
Poster Title:
The Distribution of Photospheric Fluxes
Abstract:
Using SOT, MDI (high-resolution and full disk) magnetograms magnetic
flux features are identified in the photosphere. It is found that by
using a 'clumping' algorithm, which counts a single 'flux massif' as
one feature, that all feature fluxes regardless of flux strength follow
the same distribution - a power-law - between $2\times 10^{17}$ and a
few times $10^{21}$ Mx. This result suggests that the mechanism
producing magnetic features on all current observable scales appears to
be the same. Furthermore, the power-law index of this distribution was
found to be $-1.85\pm0.15$, which suggests that the larger features
contribute more flux to the total flux of the Sun than the smaller
fragments. The value of $-1.85$ is not equal to either the Kolomogrov
$-5/3$rds slope of hydrodynamic turbulence nor the Chrichenen $-2$
slope of magneto-hydrodynamic turbulence, although both of these
numbers maybe within the error bars of our analysis.
SDO Teams Meeting
93
Author: Clare E Parnell, Andrew L Haynes, Stephane Regnier, Rhona C
Maclean
Institution: University of St Andrews
Email: clare@mcs.st-and.ac.uk
Poster Title:
New Robust Method for Finding Magnetic Null Points
Abstract:
Null points are important locations within magnetic fields. In twodimensions they are the only locations at which reconnection can occur.
In three-dimensions they are key points within the 'true' or
'topological' magnetic skeleton. In particular, one must first find the
null points within a volume, so-called coronal nulls, before separatrix
surfaces or separators may be found.
For many years a null finding method based on the Poincare index
(Greene 1988) has been used to find coronal nulls. However, recently
(Haynes & Parnell 2007) have shown that this method produces false
results for weakly non-linear fields. They have proposed a new method
which is designed to work on 3D numerical grids of magnetic fields in
different geometries. We present this new method here, including a
series of examples (eg numerical MHD experiment, Earth's magnetosphere,
non-linear force-free field extrapolations from observed active-region
magnetograms) where this method has been applied. In a couple of these
examples, we compare the results from Greene's and Haynes' methods
explaining where Greene's method fails.
SDO Teams Meeting
94
Author: William D. Pesnell, Barbara J. Thompson, and the SDO team
Institution: NASA GSFC
Email: barbara.j.thompson@gmail.com
Poster Title:
The SDO Mission
Abstract:
The Solar Dynamics Observatory is a sun-pointing semi-autonomous
spacecraft that will allow nearly continuous observations of the Sun
with a continuous science data downlink rate of 130 Megabits per second
(Mbps). The spacecraft is 4.5 meters high and over 2 meters on each
side, weighing a total of 3100 kg (fuel included). SDO's inclined
geosynchronous orbit was chosen to allow continuous observations of the
Sun and enable its exceptionally high data rate through the use of a
single dedicated ground station. This poster will detail the status of
the Solar Dynamics Observatory, focusing on the development,
integration, and preparation for the launch of the spacecraft.
SDO Teams Meeting
95
Author: M.C. Rabello-Soares1, S.G. Korzennik2, J. Schou1
Institution: ^1 Stanford University,
^2 Harvard-Smithsonian Center
for Astrophysics
Email: csoares@sun.stanford.edu
Poster Title:
Analysis of MDI high-degree mode frequencies and their rotational
splittings
Abstract:
Here we present a detailed analysis of solar acoustic mode frequencies
and their rotational splittings for modes with degree up to 900. They
were obtained by applying spherical harmonic decomposition to full-disk
solar images observed by the Michelson Doppler Imager (MDI) on board
the Solar and Heliospheric Observatory (SOHO) spacecraft.
Global helioseismology analysis of high-degree modes is complicated by
the fact that the individual modes cannot be isolated, which has
limited so far the use of high-degree data for structure inversion of
the near-surface layers (r > 0.97 R). In this work, we took great care
to recover the actual mode characteristics using a physically motivated
model which included a complete leakage matrix.
We included in our analysis the following instrumental characteristics:
the correct instantaneous image scale, the radial and non-radial image
distortions, the effective position angle of the solar rotation axis
and a correction to the Carrington elements.
We also present variations of the mode frequencies caused by the solar
activity cycle. We have analyzed seven observational periods from 1999
to 2005 and correlated their frequency shift with four different solar
indices. The frequency shift scaled by the relative mode inertia is a
function of frequency alone and follows a simple power law, where the
exponent obtained for the p modes is twice the value obtained for the f
modes. The different solar indices present the same result.
SDO Teams Meeting
96
Author: M. Cristina Rabello-Soares1, Richard S. Bogart1, Sarbani Basu2
Institution: (1) Stanford University, (2) Yale University
Email: csoares@sun.stanford.edu
Poster Title:
Analysis of the characteristics of solar oscillation modes in active
regions
Abstract:
We analyze the characteristics of high-degree solar acoustic modes in
the vicinity of magnetic active regions and compare with those of
magnetically quiet regions at the same latitude and at nearly the same
time. We applied ring-diagram analysis to GONG+ and MDI data, using the
13-parameter mode-fitting model of Basu & Antia (1999). We explore the
correlations of variations in mode frequencies, amplitudes, widths, and
asymmetries with the total magnetic flux of the analyzed regions.
SDO Teams Meeting
97
Author: S.P. Rajaguru
Institution: Indian Institute of Astrophysics
Email: rajaguru@iiap.res.in
Poster Title:
Systematics and artifacts in helioseismic travel times over active
regions.
Abstract:
We discuss the following known sources of systematics and artifacts in
time-distance helioseismic measurements over active regions: (1)
measurement-specific phase shifts arising from, (a) the altered height
range of spectral line formation and the propagating character of pmode waves in penumbrae and, (b) Zeeman broadening and splitting, (2)
phase-speed filter effects induced by strong spatial modulation of
oscillation amplitudes. The extent to which the circular polarization
line profiles of FeI (6173 A, used by HMI/SDO) would be subject to the
systematics from (1) above are also examined.
SDO Teams Meeting
98
Author: D. Salabert (1), J. Leibacher (1,2), T. Appourchaux (2), F.
Hill (1)
Institution: (1) National Solar Observatory, (2) Institut
d'Atrophysique Spatiale
Email: dsalabert@nso.edu, jleibacher@nso.edu,
Thierry.Appourchaux@ias.u-psud.fr, fhill@nso.edu
Poster Title:
How low can we go? Pushing down the lower boundary of the mode
frequency analysis in 72 and 108-day time series
Abstract:
We have developed a new mode-fitting analysis technique using the
rotation-corrected, m-averaged spectrum. The frequency shift of each of
the 2\ell+1 m spectra of a given (n, \ell) multiplet is chosen that
yields the narrowest mode in the m-averaged spectrum. In the case of
spatially-resolved helioseismic data (such as HMI, MDI, and GONG
observations), m-averaged spectra appeared to offer a powerful tool,
since for a given multiplet (n, \ell), there exist 2\ell+1 individual-m
spectra, so that even if the individual-m spectra have a very low SNR,
which would preclude finding modes, once the individual-m spectra are
corrected for the rotation- and structure -induced shifts the maveraged spectrum can result in a SNR
1. Moreover, thanks to an enhanced SNR, the observed mode parameters
are measured with a greater accuracy, and the resulting inversions are
therefore more precise. Initially developed to measure low-frequency
solar p modes with low- and intermediate-angular degrees (1 \leq \ell
\leq 35) in long time series of GONG and MDI data (Salabert et al
2007), this technique is applied here to the canonical 72-day MDI and
108-day GONG time series. We compare the acoustic modes below 2000\muHz
with 1 \leq \ell \leq 35 measured with the m-averaged spectrum
technique and with the fitted modes obtained through the MDI and GONG
peak-fitting pipelines, for the same time intervals. We show that the
m-averaged spectrum technique, beside being an alternative approach to
measure solar oscillations, gives us access to a whole new range of
predicted (low SNR) modes but which had not been successfully fitted by
the current MDI and GONG peak-fitting pipelines in the low-frequency
range for low and intermediate angular degrees.
SDO Teams Meeting
99
Author: Deborah Scherrer, Anna Kosovicheva, Shannon Lee, Sean Liu,
James Mason, Bryan Scherrer, Scott Winegarden
Institution: Stanford Univerity, UC Berkeley, Cal State U at San
Francisco, UC Berkeley, UC Santa Cruz, high school, UC Irvine
Email: dscherrer@solar.stanford.edu
Poster Title:
Encouraging Summer Students in Science by Involving them with EPO:
Case Studies
Abstract:
You have a bevy of high school and undergraduate students showing up
for a summer "science experience". What are you going to do with them
to stimulate their interest and encourage them to continue in science?
We chose to involve our summer students in our education and public
outreach projects, training them in inquiry-based methods, hands-on
activities, and collaborative learning, along with providing
opportunities for them to acquire knowledge of solar science. Our
poster highlights, in their own words, projects our students undertook,
their trials, tribulations, and learning experiences.
SDO Teams Meeting
100
Author: Deborah Scherrer
Institution: Stanford Solar Center
Email: dscherrer@solar.stanford.edu
Poster Title:
Space Weather Monitoring for the IHY:
Involving Students Worldwide in the Research Process
An EPO Project of the HMI Instrument Team
Abstract:
The Stanford Solar Center, EPO arm of the SDO/HMI team, NASA, and NSF
have joined forces to distribute space weather monitors to high schools
worldwide for the International Heliophysical Year. Our international
collaboration involves researchers, educators, and students who are
collecting and analyzing research-quality scientific data to understand
how the ionosphere responds to output from the Sun and to internal
disturbances.
SDO Teams Meeting
101
Author: P.H. Scherrer & The HMI Team
Institution: Stanford Universtity
Email: phil@sun.stanford.edu
Poster Title:
HMI - The Helioseismic and Magnetic Imager on SDO
Abstract:
The HMI investigation will study the origin of solar variability and
will characterize and understand the Sun’s interior and the various
components of magnetic activity. The HMI instrument is part of the
Solar Dynamics Observatory (SDO) mission scheduled for launch in 2009.
HMI measures the motion of the solar photosphere to study solar
oscillations and measures polarization to study the Sun’s vector
magnetic field. HMI will help establish the relationships between the
internal dynamics and magnetic activity in order to understand solar
variability and its effects, leading to reliable predictive capability,
one of the key elements of the Living With a Star (LWS) program.
The Michelson Doppler Imager (MDI) instrument has been making
helioseismic and magnetic field observation of the Sun for most of
solar cycle 23. HMI will continue these important measurements from
space into the next solar cycle. The HMI instrument is an evolution of
the successful MDI design with key improvements in resolution, image
cadence and vector magnetic field measurement capabilities.
Measurements of the Fe I spectral line at 617.3 nm with the HMI tunable
narrow band filter determine motions of the solar photosphere to study
solar oscillations. Measurements of the polarization in this same
spectral line enable determination of all three components of the
photospheric magnetic field.
SDO Teams Meeting
102
Author: Takashi Sekii(1), Kaori Nagashima (1), Alexander Kosovichev(2),
Junwei Zhao(2), Urmila Mitra-Kraev(3)
Institution: (1)NAOJ, (2)Stanford University, (3)University of
Sheffield
Email: sekii@solar.mtk.nao.ac.jp
Poster Title:
First results from Hinode/SOT helioseismology programme
Abstract:
We are reviewing first results from the Hinode/SOT helioseismology
programme that exploits the stable high-resolution observation
capability of the Solar Optical Telescope on the Hinode satellite. The
focus will be on those results from the Broad-band Filter Imager,
obtained before the Narrow-band Filter Imager Dopplergrams became
available. The issues these results raise, and the follow-up
observations that are required to resolve these issues, particularly
now that the NFI Dopplergrams are available, will be discussed.
SDO Teams Meeting
103
Author: Robert Sych, Valery Nakariakov and Sergey Anfinogentov
Institution: Institute of Solar-Terrestrial Physics SB RAS, Irkutsk,
Russia; CFSA, Warwick University, Coventry, UK
Email: sych@iszf.irk.ru
Poster Title:
Interactive remote data processing using the Pixelised Wavelet
Filtering and Periodmapping methods
Abstract:
Wavelet analysis is routinely used for investigating waves and
oscillations in the solar atmosphere, which are limited in both time
and frequency. The analysis of spatially resolved low quality multimodal wave phenomena can be performed by the recently designed
Pixelised Wavelet Filtration method (PWF-method) (Sych & Nakariakov,
Solar Phys. DOI: 10.1007/s11207-007-9005-7; 2008). This method allows
us to obtain information about the presence of propagating and standing
waves in the imaging data cubes, and localise them precisely in time
and in space. The algorithm has been extensively tested, and the
results on the coronal wave detection were found to be consistent with
those obtained in some limiting cases by other methods (e.g. the
empirical mode decomposition). The PWF method can be well complimented
by the Periodmapping technique (Nakariakov & King, Solar Phys. 241,
397, 2007), as a pre-analysis tool.
The procedure for the detection of coronal waves in large imaging
datacubes, in particular, generated by SDO/AIA, can include two steps:
firstly, the periodmap analysis is performed, identifying the time
intervals and spatial fields-of-interest, which are likely to contain
coronal waves and oscillations. Secondly, the sub-cubes identified by
the periodmapping method or otherwise, will be processed with the PWF
method. This approach can be implemented either in the automatic or in
the hands-on operation modes.
As a proof-of-principle of the proposed approach, we have developed the
remote data processing web-based system at the Institute of SolarTerrestrial Physics, Irkutsk. The system is based upon the data
processing server - http://pwf.iszf.irk.ru. The main aim of this
resource is the creation, in remote access through the local and/or
global network (the Internet), narrowband maps of wave sources both in
the whole spectral band and at certain chosen spectral bands. In
addition, the system allows for the creation of the movies (in the mpeg
format) of temporal dynamics of the main oscillation characteristics:
amplitude, power and phases, in a prescribed frequency band. The system
also allows for the quick period mapping of the submitted data.
The on-line system is based upon applications ION-scripts, the
algorithmic languages IDL and PHP, and Apache WEB server.
SDO Teams Meeting
104
Author: Barbara J. Thompson and William D. Pesnell
Institution: NASA GSFC
Email: barbara.j.thompson@gmail.com
Poster Title:
Data Access and Browse Pages for the SDO Home Page
Abstract:
This poster will review possible options for data access and browse
interfaces from the SDO home page. Ideally, this would be a relatively
simple access point that leads users to the necessary resources as
efficiently as possible. The site will include links to the instrument
data, browse data, ancillary data, software, analysis tools, the
Virtual Solar Observatory, helioinformatic tools, as well as other
sources of data or information of use to the broad SDO user community.
SDO Teams Meeting
105
Author: Gerard Thuillier, Steven Dewitte, Werner Schmutz
Institution: Service d'Aeronomie du CNRS, Royal Meteorological
Institute of Belgium, Physikalisch-Meteorologisches Observatorium Davos
Email: Gerard.Thuillier@aerov.jussieu.fr
Poster Title:
The Picard Mission
Abstract:
The Picard mission will measure the total and spectral solar
irradiance, solar diameter, limb shape, solar asphericity, and
helioseismic waves. These measurements, which represent key inputs to
validate solar models and to understand the origin of the solar
activity, will be carried out by absolute radiometers, sunphotometers,
and an imaging telescope onboard a microsatellite built by the French
Space Agency CNES, with launch foreseen for 2009. Picard and the NASA
Solar Dynamics Observatory will be in space at the same period for
complementary, simultaneous measurements. Given the specific
observations of each mission, a strong synergy exists between these two
programs. Past and present solar diameter measurements reveal
discrepancies among results with solar activity consisting of
correlation, anticorrelation, or no variation. To understand the role
of the atmosphere, ground-based instruments will be also run during the
mission allowing Picard to extent its domain of interest to atmospheric
physics by comparing ground and space simultaneously.
SDO Teams Meeting
106
Author: Alan Title
Institution: Stanford Lockheed Institute for Space Research
Email: title@lmsal
Poster Title:
AIA
Abstract:
The AIA instrument has been through all of its testing at the
laboratory and is currently integrated with the SDO spacecraft at GSFC.
The first comprehensive test of the entire SDO system as been completed
successfully. By the time of the meeting the pre-environmental review
will have been completed and EMI-EMC and thermal testing of the
completed instrumented instruments and spacecraft will begin. While
there are some minor problems with EVE and the spacecraft there are
currently no major problems. The poster will illustrate the current
state of the instrument.
SDO Teams Meeting
107
Author: W. Kent Tobiska
Institution: Space Environment Technologies
Email: ktobiska@spacenvironment.net
Poster Title:
Use of SDO solar data products for operational systems
Abstract:
Precision satellite orbit determination, constellation station-keeping,
debris avoidance, reentry timing, and communication link enhancement
are among the major technological activities that are affected by space
weather. We report on progress towards providing applications and
services for operational systems that mitigate adverse effects caused
by space weather. These applications and services will use SDO solar
data products. In particular, Space Environment Technologies (SET) has
developed new solar indices that reduce 1-sigma uncertainty by 50% in
atmosphere density calculations and new solar irradiances that capture
solar flare effects on transionospheric communications. These solar
products have been developed and tested for: 1) daily time resolution
for historical, now cast, and intermediate-term forecast periods (1-day
granularity, 1-hour cadence, and 1-hour latency extending 4.5 months);
2) high time resolution for recent, now cast, and short-term forecast
periods (3- hour granularity, 1-hour cadence, and 1-hour latency
extending 96 hours); and 3) precision time resolution for recent,
current epoch, and near-term forecast periods (1-minute granularity, 2minute cadence, and 5-minute latency extending 6 hours). We describe
how these indices and solar irradiances will be improved using SDO data
and how applications serving space systems users in orbit planning,
satellite operations, and communication activities will be enhanced.
SDO Teams Meeting
108
Author: Vial, J.-C., Appourchaux, T., Auchère, F., Buchlin, E.,
Bocchialini, K., Quémerais, E., Soubrié, E.
Institution: Institut d'Astrophysique Spatiale (I.A.S.), Orsay, France
Email: jean-claude.vial@ias.u-psud.fr
Poster Title:
I.A.S. contribution to SDO
Abstract:
The Institut d'Astrophysique Spatiale has various interests in the
Solar Dynamics Observatory because of the unique features of its
instrumentation and mission profile which provide observational
opportunities for its on-going activities. The AIA (and HMI)
instruments will enable to detect and characterize prominence
oscillations whose changes can be the precursors of eruptions
(Régnier et al. 2001; recently, Chen et al. 2008). The detection
depends on the interpretation in changes of emissivity and morphology
that we plan to characterize with the help of Non-LTE modelisation
(Labrosse et al.2008). In collaboration with SAO, we plan to build
codes including the detection of such events, their datation and their
cataloging for use by the community at large. We also want to use the
exceptional high temperature coverage of AIA for building statistics on
micro-nano-events in order to validate recent models coupling
hydrodynamics and radiation (Buchlin et al. 2008). The EVE data will
allow to compute the H and He photoionization rates in the
interplanetary medium, at all latitudes (Quemerais et al. 2006).
The 3D UV and EUV flux in the heliosphere will be modelized on the
basis of the AIA images along the method of Auchère et al. (2005). We
also envisage to use the HMI data for detecting very low-frequency p
modes with unprecedented accuracy that will provide the structure of
the interior of the Sun (Salabert, Leibacher and Appourchaux, 2007).
SDO Teams Meeting
109
Author: R. Wachter, S. P. Rajaguru
Institution: Stanford University
Email: richard@sun.stanford.edu
Poster Title:
Helioseismology with Spectro-Polarimetric Data: Data processing and
first results from IBIS observations in Fe 6173 and Fe 7090
Abstract:
Spectrally resolved images of a sunspot have been obtained in June 2007
with the IBIS instrument installed at Dunn Solar Telescope at
Sacramento Peak. We got full line scans in a magnetic (Fe I 6173) and a
nonmagnetic (Fe I 7090) line with a cadence of 47.5 seconds
continuously for almost 8 hours.
Standard-sized helioseimology data cubes for a number of observables
can be obtained. In particular, the nonmagnetic line provides reliable
Dopplergrams in the umbral region.
We describe the data processing and show first results. We discuss the
scientific potential of these data.
SDO Teams Meeting
110
Author: R. W. Walsh, A. Sarkar & J. Noglik
Institution: University of Central Lancashire
Email: rwwalsh@uclan.ac.uk
Poster Title:
Multi-stranded, nanoflare-heated coronal loops: implications for and
possible discrimation by SDO instrumentation
Abstract:
There is a growing body of evidence that active region loops observed
with current instrumentation (such as EIT, TRACE and XRT) may actually
consist of numerous sub-resolution elements. Thus, the total emission
we observe is the cumulative result of the radiative losses from
numerous evolving plasma strands.
This poster presents a "global loop" as many (100's to 1000's)
individual strands where each fundamental element is modeled
independently by a one-dimensional hydrodynamic simulation. The energy
release mechanism across the strands consists of localized, discrete
heating events (nanoflares) and the strands are "coupled" together
through the frequency distribution of this energy input which follows a
given power law distribution.
As well as examining the implications for the spatial preference the
heat input, the simulated data is folded through the response functions
for the range of spectral lines to be observed by SDO AIA. The
resulting line intensities, DEM curves and filling factor calculations
will be presented. The implications of these results on subsequent
analysis of the SDO AIA datasets will be outlined.
SDO Teams Meeting
111
Author: B.T. Welsch, C.E. DeForest, H.J. Hagenaar, J.A. Klimchuk, D.A.
Lamb,C.E. Parnell, T.D. Tarbell
Institution: SSL-UCB, SWRI-Boulder, LMSAL, NASA-GSFC, SWRI-Boulder,
Univ. St. Andrews, LMSAL
Email: welsch@ssl.berkeley.edu
Poster Title:
On the Motions of Quiet-Sun Features Tracked in Hinode/SOT Magnetograms
Abstract:
We have identified and tracked convex magnetic features in a sequence
of Na-D line-of-sight magnetograms, recorded by the Solar Optical
Telescope (SOT) on Hinode. We first analyze the spatial distribution
of features --- e.g., distances to nearest neighbors of like and
opposite polarity --- and find that like-polarity features are
clustered, consistent with the concentration of magnetic flux in
granular and supergranular downflow lanes. Next, we present a
statistical analysis of the properties of displacements of tracked
features --- e.g., typical step sizes, typical changes in direction
between steps, and integrated displacements --- on the smallest scales
yet observed from space. Generally, we find that the features we track
do not maintain their integrity long enough to be observed to wind
around other features. A popular coronal heating model, advocated by
Parker, is that random convective motions "shuffle" the photospheric
footpoints of magnetic fields that thread the corona, thereby inducing
electric currents (perhaps current sheets) in the coronal magnetic
field, and that dissipation of these currents then heats the coronal
plasma. Our results suggest that, if such shuffling of field lines
does occur, it must take place on scales smaller than features resolved
by Hinode/SOT.
SDO Teams Meeting
112
Author: B. T. Welsch, G. H. Fisher, W. P. Abbett, D. J. Bercik
Institution: Space Sci. Lab, UC-Berkeley
Email: welsch@ssl.berkeley.edu
Poster Title:
Using Photospheric Flows Estimated from Vector Magnetogram
Sequences to Drive MHD Simulations
Abstract:
Dynamic models of magnetic field above the solar photosphere show
promise as space weather forecasting tools.
Such models should be driven by velocities or electric fields derived
from sequences of photospheric vector magnetograms, the only routine
measurements of the solar magnetic field currently available.
Previous efforts have focused on deriving flows --- or, equivalently,
ideal electric fields --- consistent with evolution of the normal
photospheric field, which could be used in "component driving" of an
MHD model, i.e., enforcing consistent evolution of the observed and
modeled normal magnetic fields.
Here, we present an extension of the flow-based, component-driving
approach: we demonstrate how to derive flows (or, equivalently, ideal
electric fields) consistent with the observed evolution of both the
normal magnetic field and normal electric current, to determine
velocities that can be used for "ideal vector driving" (IVD), i.e.,
enforcing consistency between the evolution of all three components of
the observed and model photospheric magnetic vectors.
While IVD does not require tracking magnetograms to derive flows or
ideal electric fields, it can incorporate tracking results.
Driving an MHD model via IVD requires specification of both the
velocity vector and its vertical derivative at the model's bottom
boundary.
SDO Teams Meeting
113
Author: T. N. Woods and 14 co-authors
Institution: LASP / University of Colorado
Email: tom.woods@lasp.colorado.edu
Poster Title:
SDO EUV Variability Experiment (EVE):
Plans
Instrument Overview and Science
Abstract:
The highly variable solar extreme ultraviolet (EUV) radiation is the
major energy input into the Earth’s upper atmosphere and thus impacts
the geospace environment that affects satellite operations,
communications, and navigation. The Extreme ultraviolet Variability
Experiment (EVE) aboard the NASA Solar Dynamics Observatory (SDO) will
measure the solar EUV irradiance from 0.1 to 105 nm with unprecedented
spectral resolution (0.1 nm), temporal cadence (10 sec), and accuracy
(20%). The EVE program will provide solar EUV irradiance data for the
NASA Living With the Star (LWS) program, including near real-time data
products to be used in operational atmospheric models that specify the
space environment and to assist in forecasting for space weather
operations. The EVE program is expected to make significant progress
towards real understanding of the physics of the solar EUV irradiance
variations on time scales from flares to the solar cycle. This
progress, which includes providing better predictions, will be made
through utilizing simultaneous measurements of the solar EUV irradiance
and full Sun images of magnetic fields and brightness at wavelengths
emitted from the chromosphere, transition region, and corona, which are
obtained by other SDO instruments.
SDO Teams Meeting
114
Author: A.R. Yeates, D.H. Mackay, A.A. van Ballegooijen
Institution: University of St Andrews, University of St Andrews,
Harvard-Smithsonian Center for Astrophysics
Email: anthony@mcs.st-and.ac.uk
Poster Title:
EVOLUTION OF CURRENT HELICITY IN FULL-SUN SIMULATIONS
Abstract:
Current helicity quantifies locations of magnetic stress in the corona,
and thus the likely source regions of flare and CME activity. It may be
determined locally from high-resolution vector magnetic field
measurements, which will be routinely made for the first time over the
full visible disk by the HMI instrument on SDO. These new observations
will be ideal for comparison with our recently-developed simulations of
the global coronal magnetic field evolution over a period of 30 months.
In our model helicity originates from (1) shearing by photospheric
motions and (2) the emergence of twisted magnetic bipoles throughout
the simulation. We calculate global averages of current helicity
showing a systematic variation with latitude, but our model also allows
us to study the distribution of helicity within a single active region
as it moves across the disk. In our nonlinear force-free model local
values may be much higher than found in linear force-free fields (which
have constant current helicity).
SDO Teams Meeting
115
Author: Young (1), Ireland (1), McAteer (2), Gallagher (2), and Byrne
(2)
Institution: (1) ADNET Systems Inc, NASA/GSFC (2) School of Physics,
Trinity College Dublin
Email: c.alex.young@nasa.gov
Poster Title:
Multiscale feature enhancement and detection in solar image data
Abstract:
The information contained in solar image data exists at many different
scales. This makes multiscale transforms such as wavelets and curvelets
a near optimal choice to represent this data. We present examples of
these transforms applied to solar image data to enhance and detect
features of interest.
SDO Teams Meeting
116
Author: Vasyl Yurchyshyn, Phil Goode
Institution: Big Bear Solar Observatory of New Jersey Institute of
Technology
Email: pgoode@bbso.njit.edu
Poster Title:
The New Solar Telescope
Abstract:
Progress in building the NST (New Solar Telescope) will be reported.
The NST is a 1.6 m clear aperture, off-axis solar telescope. The
telescope is scheduled to see first light at Big Bear Solar Observatory
(BBSO) in Spring 2008. First light will be fed to the Gregorian focus
on the Nasmyth bench.
The telescope is off-axis to optimize low-contrast imaging, and will
have a 3 arcminute field of view. Figuring and testing the figure of
the large off-axis primary mirror presented unique problems. The NST
will have wavefront sensor controlled, real-time active optics, and
ultimately its light will feed BBSO’s adaptive optics (AO) system,
which in turn feeds infrared and visible light Fabry-Perot based
polarimeters, as well as a real-time image processing system utilizing
parallel processing and a spectrograph. The polarimeters, AO image
reconstruction systems, and spectrograph will reside in the Coude Room
below and all but the spectrograph have already been tested with light
fed from the old BBSO telescope.
The NST replaces the old 0.6 m solar telescope at BBSO, and required a
new, larger, vented dome with new thermal and telescope control
systems.
The complementary value of the telescope for upcoming space missions,
such as SOLAR-B, STEREO and SDO will be shown.
SDO Teams Meeting
117
Author: X. P Zhao, J. T. Hoeksema, Y. Liu, P. H.
Institution: Stanford University
Email: xuepu@sun.stanford.edu
Poster Title:
Inverting three components of large-scale photospheric magnetic vectors
using observed line-of-sight components and a new least square
fit
approach
Abstract:
The large-scale photospheric magnetic field is often assumed to
beradially pointed in extrapolating it into the corona. Using a leastsquare fit of observed line-of-sight component to a simple projection
model, the angle between the field line and its local radial vector, as
projected onto the plane of the latitude and line-of-sight, has been
determined, however, to be not zero in general [Shrauner and Scherrer,
1994].
We extend this approach into 3-D from 2-D and show that all three
components of photospheric magnetic fields that form a line-of-sight
component can be well inverted from the line-of-sight component using
the extented approach if photospheric fields are stable in a time
interval of several days.
We plan to use the extended approach to HMI observations of line-ofsight components to improve the HMI synoptic chart of radial
components, and to see if the inverted three components are helpful in
solving the problem ofthe 180-degree ambiguity in vector magnetograms,
especially for large-scale fields outside active regions.
SDO Teams Meeting
118