Soundings from Current and Future
Geostationary Satellites
Timothy J. Schmit
NOAA/NESDIS, SaTellite Applications and Research
(STAR), Advanced Satellite Products Branch (ASPB)
Madison, WI
The United States Geostationary Operational Environmental Satellite (GOES) Sounders (GOES-8/9/10/11/12) have provided hourly infrared (IR) radiances and derived products over the continental
U.S. (CONUS) and adjacent oceans for over 14 years. The GOES-10 sounder now also provides hourly coverage over South America. The products derived include: clear-sky radiances; temperature
and moisture profiles; Total Precipitable Water vapor (TPW) and layer PW; total column ozone; atmospheric stability indices such as Lifted Index (LI); cloud-top properties; and water vapor motion
vectors. These products are used in numerical weather prediction (NWP), short range forecasts and nowcasts that include severe weather forecasts.
While broadband geo-sounding has proven useful, it has been demonstrated that geo hyperspectral IR sounding would provide measurements that serve user requirements much better. Studies with
available aircraft and polar-satellite data have illustrated the usefulness of hyperspectral IR radiances and products, and the importance of high spatial, high temporal and high spectral resolutions. High
spectral resolution would enhance support of regional and convective-scale NWP, as it will provide unprecedented detail in 3D fields of wind, temperature, and humidity. Nowcasting/very-short range
forecasting will benefit from the improved monitoring of moisture convergence and convective instability. On the next generation series of Geostationary Operational Environmental Satellite (GOESR/S), the ABI will have to be used to provide ‘legacy sounder products'. The need for an (IR) sounder dedicated to acquiring high vertical resolution atmospheric temperature and humidity profiles will
James J. Gurka
NOAA/NESDIS, GOES-R Program Office, Greenbelt, MD have to be addressed on subsequent GOES.
Jun Li
Cooperative Institute for Meteorological Satellite Studies
(CIMSS), University of Wisconsin-Madison, Madison, WI
Jaime Daniels and Mitch Goldberg
1. Current GOES Sounders
NOAA/NESDIS, STAR, Camp Springs, MD
Level 1 to Level 2
W. Paul Menzel
Level 2 to applications
Description: GOES-I(8)/P Sounders
CIMSS, University of Wisconsin-Madison, Madison, WI
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Thanks also to…
Gary S. Wade, NOAA/NESDIS/ASPB
Zhenglong Li, CIMSS
Jinlong Li, CIMSS
Xin Jin, CIMSS
Jim Nelson, CIMSS
Scott Bachmeier, CIMSS
Steve Ackerman, CIMSS
Many others
View from space
1800 UTC
19 channels (18 Infrared; 1 Visible)
Spatial resolution: ~ 10km
Hourly scanning over CONUS and adjacent waters
Products include standard imagery and derived, Level-2 products
Hourly LI indicates instability
5 hours before
OK tornado 3 May 99
View from ground
530 CDT (2330 UTC)
Lifted Index
Total Precipitable Water
2300 UTC
Current GOES sounder obtains 18 broad spectral IR bands
Current GOES Sounder spectral coverage.
GOES Sounder Product Operational Use within the NWS
Surface Skin Temperature
Cloud-Top Height
2. Current GOES Sounder Products and Applications
Clear-sky Radiances
Assimilation into NCEP operational regional & global
NWP models over water
Layer & Total Precipitable
Water
Assimilation into NCEP operational regional global NWP
models; display and animation within
NWS AWIPS for use by forecasters at
NWS WFOs & National Centers in
forecasting precipitation and severe
weather
Cloud-top retrievals (pressure,
temperature,
cloud amount)
Real Time Mesoscale Analysis
(RTMA)
Assimilation into NCEP operational regional NWP
models; display and animation within
NWS AWIPS for use by forecasters at
NWS WFOs; supplement to
NWS/ASOS cloud measurements for
generation of total cloud cover product
at NWS/ASOS sites
Surface skin temperature
Image display and animation within NWS AWIPS for use
by forecasters at NWS WFOs
Profiles of temperature &
moisture
Display (SKEW-Ts) within NWS AWIPS for use by
forecasters at NWS WFOs in
forecasting precipitation and severe
weather
Atmospheric stability indices
Image display and animation within NWS AWIPS for use
by forecasters at NWS WFOs in
forecasting precipitation and severe
weather
Water Vapor Winds
Image display and animation within NWS AWIPS for use
by forecasters at NWS WFOs
Air mass tracking 22 UTC, 13 April 2006
Air mass tracking 00 UTC, 14 April 2006
Clustering using 15
Sounder radiances
Air mass tracking 03 UTC, 14 April 2006
Clustering using 15
Sounder radiances
Dry air
Dry air
Dry air
Conditionally
Unstable
Super Cell
22 UTC to
00 UTC
14 April 2006
GOES
Sounder
retrieved RH
Conditionally
Unstable
Super Cell
GOES
Sounder
retrieved RH
Potentially convective unstable43
Hail Storm (April 13 – 14, 2006),
Madison, WI
23 UTC, 13 April
To 03 UTC,
14 April 2006
Super Cell
GOES
Sounder
retrieved RH
44
45
The hail storm of April 13 – 14, 2006 caused damage to many houses in and near Madison, Wisconsin. The storm produced large hail. The GOES-12 Sounder 11 µm image at 22 UTC on 13 April shows that a
super cell is likely to develop. The multispectral band classification (Li et al. 2003, JAM) shows that there are typical four classes of clear air mass surrounding the super cell, two hours later (00 UTC, 14 April
2006) the dry air moves toward east while the moist air moved north. The clear sky atmosphere is very unstable from 22 UTC to 00 UTC, and the super cell starts to develop. From 00 UTC on 14 April to 03
UTC on 14 April, the air masses continue to move, the super cell develops fast and becomes convective system. The soundings observed by GOES Sounder proved useful for short range storm forecasts.
Operational Products from the current GOES Sounder.
Pressure (mb)
AIRS (green) and GOES (red)
Relative Humidity (RH)
retrievals.
High-spectral resolution
instrument is in much better
agreement with in situ
measurement.
Relative Humidity (%)
The improved vertical
resolution identifies unstable
environments, which is
critical for both nowcasting
and NWP applications
GOES-12 Sounder Bands
Smooth over required absorption lines
Independent IASI and AIRS retrievals show similar
temperature and moisture distributions
IASI Retrievals (15:48 UTC April 29, 2007)
(a) Temperature deviation from granule mean (K)
(b) Relative humidity (%)
Radiosonde
Dropsondes
AIRS Retrievals Interpolated to IASI FOV (19:30 UTC April 29, 2007)
(a) Temperature deviation from granule mean (K)
Compared to broadband sounders, observing absorption lines is
mandatory to meeting requirements for temperature and moisture
structure needed to improve weather forecasting
(c) Cross section track on surf. temp. (K)
(c) Cross section track on surf. temp. (K)
(b) Relative humidity (%)
(1) To depict water vapor, the key indicator for severe thunderstorms, in detail as never before. Large variations in atmospheric water vapor occur over a scale of 10
km or finer in the horizontal and 1 km in the vertical. Large variations in water vapor occur over 10s of minutes. Thunderstorms form or decay in 10s of minutes.
Severe thunderstorms form mostly over land, but accurate temperature and moisture profiles from satellite are challenging due to land emissivity variations.
(2) To support regional and convective-scale NWP over CONUS through unprecedented detail in 3D fields of wind, temperature and humidity at high temporal
resolution.
(3) To support nowcasting and very-short range forecasting (VSRF), for example in monitoring moisture convergence and convective instability to help improve
warnings of location and intensity of convective storms.
(4) To provide soundings and wind profiles that are critical for meso-scale NWP and short range forecasts. These would enable 3D depiction of moisture with the
temporal and spatial scales necessary to forecast thunderstorms. Hyperspectral coverage will show the variations in surface emissivity as well as low level
temperature inversions necessary for deriving accurate temperature and moisture profiles as well as enable radiance data assimilation over land.
Acknowledgements: This study is partially supported by the GOES-R program office. The views, opinions, and findings contained in this report are those of the
authors and should not be construed as an official National Oceanic and Atmospheric Administration or U.S. Government position, policy, or decision.
Analysis courtesy of Dan Zhou, NASA
Profile Information Content
Number of Pieces of Information .
Dropsonde is an in situ
observation of the atmosphere
from an aircraft (blue)
Analysis courtesy of Justin Sieglaff,
CIMSS.
3. Needs for Geostationary Hyperspectral IR Sounding System
Comparison of Vertical
Profiling Capabilities.
20
Temperature information
Water Vapor (relative humidity) Information
16
12
8
4
0
RAOB (to 100
hPa)
HES
GOES Sounder ABI + Forecast GOES Sounder
+ Forecast
ABI (5x5)
The relative vertical information is shown for
radiosondes, a high-spectral infrared sounder, the
current broad-band GOES Sounder and the ABI. The
high-spectral sounder is much improved over the
current sounder. This information content analysis
does not account for any spatial or temporal
differences.
Clear sky AIRS SFOV temperature retrievals, each pixel
provides vertical temperature and moisture soundings
(K)
High temporal and spatial
resolutions of geostationary
advanced sounder could
monitor unique aspects
regarding severe weather
forecast by
• depicting important water
vapor variations spatially and
temporally;
• improving thunderstorm
predictions;
• providing better emissivity
determination over land; and
• enabling better detection of
low level inversions.
Tracks of ensemble mean analysis on Hurricane Ike
CTL run: Assimilate radiosonde, satellite
cloud winds, aircraft data, and surface data.
AIRS
NCAR WRF/DART ensemble assimilation (36 km)
NCEP 1 degree global analysis is used as initial conditions
Analysis from 06 UTC 6 to 00UTC 8 September 2008
500 hPa Temperature on 06 September 2008
(K)
CIMSS/UW
Hui Liu (NCAR) and Jun Li (CIMSS)