Weather on Other Planets
Abstracts and biographies from the speakers
Prof Raymond T. Pierrehumbert
From Snowball Earth to Rock Vapour Atmospheres: The diversity and unity of planetary weather
Abstract:
Planetary climate is governed by a relatively few basic principles of physics, primarily those related to thermodynamics, radiative
transfer and classical mechanics (in the form of fluid dynamics). Yet, the same few principles can combine in different ways to
produce a striking variety of weather and climate behaviour. In this talk I will provide a glimpse of this diversity, drawing on
examples from the Solar system and from hypothetical climates of some of the newly discovered exoplanets. Examples will
include the similarities between the climates of Snowball Earth and Early Mars, the fundamental resemblance of Titan’s climate
(with surface temperatures of around 100K) to a hotter version of Earth’s tropics, the application of circulation concepts familiar
from the Earth’s tropics to tide-locked exoplanets, and transonic atmospheres occurring on icy bodies like Triton and on highly
illuminated rocky planets where rock-vapour atmospheres and permanent magma oceans are expected. I will also discuss some of
the special features of planetary atmospheres under the illumination of M-dwarf stars and show how familiar concepts like the
greenhouse effect and ice-albedo feedback play out when the spectrum of stellar illumination is different from that of our Sun.
Bio
Raymond T. Pierrehumbert is the Halley Professor of Physics at University of Oxford, having previously the Louis Block
Professor in Geophysical Sciences at the University of Chicago. During 2014/2015 he held the Kung Carl XVI Gustaf visiting
chair in environmental science at Stockholms Universitet. His research interests cover a variety of problems in planetary climate
from a theoretical and modeling perspective, including deep-time paleoclimate, anthropogenic climate disruption, the
Anthropocene, Venus, Mars, Titan and hypothetical climates of the newly discovered exoplanets. He is the author of Principles of
Planetary Climate, published by Cambridge University Press. Prof. Pierrehumbert is a Fellow of the American Geophysical Union
and the American Academy of Arts and Sciences, a Chevalier de l'Ordre des Palmes Academiques, and holder of a doctorate
honoris causa from Stockholms Universtet.
Dr John Rogers
Weather Measurements on Jupiter from the ground
Abstract
Jupiter displays a wide variety of distinctive weather patterns, constrained within a fixed framework of alternating eastward and
westward jets. Most of the important weather features are large enough to be readily observable from Earth, and have been
monitored for more than a century. With the use of modern video cameras and software, amateur images now enable monitoring
at higher spatial and temporal resolution than ever before. They make it possible, for example, to determine zonal wind profiles
and measure internal circulation of the Great Red Spot. They also allow detailed study of infrequent large-scale climatic
disturbances which unfold over several years; so by integrating modern ground-based observations with the historical record and
with physical insights from spacecraft data, it is possible to interpret these disturbances in terms of meteorological processes.
Bio
Dr John Rogers is author of ‘The Giant Planet Jupiter’ (CUP, 1995) and director of the Jupiter Section of the British
Astronomical Association. In this capacity he coordinates and analyses observations of Jupiter by amateur imagers around the
world, producing reports posted on the BAA web pages, and liaising with planetary scientists. Professionally, he was a lecturer in
neurobiology at the University of Cambridge until his retirement last year.
Dr. Leigh Fletcher
Weather Measurements on Jupiter and Saturn from Space Missions
Abstract
Giant planet atmospheres present unique conditions for the exploration of planetary climate and meteorology, free from the
complicating influence of terrestrial. Much of our knowledge of Jovian weather comes from only a narrow slither of atmosphere
accessible to remote sensing (the weather layer), and the long timescales required to understand climate variability over a Jupiter
or Saturn year means that the gas giants still present an extreme challenge for observers. Planetary orbiters, such as
Galileo (1995-2003), Cassini (2004-2017) and Juno (2016-2018), carry a suite of remote sensing instrumentation from the
microwave to the ultraviolet that provide sounding from the churning cloud decks to the overlying stratosphere, allowing us to
investigate the processes governing the transport of energy and material both horizontally and vertically. We will review the
contribution of these missions to our growing understanding of gas giant climatology – from Hadley-type circulation
patterns, powerful upwelling and quasi-periodic stratospheric oscillations at tropical latitudes; to vortex genesis and
storm eruptions at temperate latitudes; and to long-lived waves, polar cyclones and extreme seasonal variability at planetary
poles. Finally, we will look ahead to novel new instrumentation on the NASA/Juno and ESA/JUICE missions that will further
expand our knowledge of the forces shaping planetary weather on a giant scale.
Bio
Dr. Leigh Fletcher is a Royal Society Research Fellow and Lecturer at the University of Leicester, specialising in remote sensing
of the climates and environmental conditions within giant planet systems, both in our solar system and around other stars. He
earned a PhD in Planetary Physics from Oxford, and has since worked as a NASA fellow at the Jet Propulsion Laboratory and as a
Research Fellow at Oxford, before moving to Leicester in 2015. He is actively involved in remote sensing of the Saturn system
from Cassini, ground-based planetary astronomy, and is an Interdisciplinary Scientist (IDS) on the science team for Europe’s first
mission to Jupiter (JUICE). You can follow his research on Twitter (@LeighFletcher).
Dr Chris Arridge
Weather measurements on Uranus and Neptune
Abstract
The Ice Giant worlds of Uranus and Neptune are fundamentally different to the Gas Giants. Uranus in particular presents the
fascinating challenge to our understanding of planetary bodies with its extreme 98° obliquity, poorly constrained interior structure,
negligible internal heat flux, and sluggish atmospheric circulation. Uranus’ atmosphere is unique in that it receives a negligible
flux of heat from the deep interior but experiences extremes of seasonal forcing, with each pole spending decades in darkness. The
resulting cold temperatures and enrichment of heavy elements yield physicchemical conditions that are unique in our Solar
System. Uranus presents an extreme test of our understanding of planetary atmospheric dynamics, energy and mass transport,
seasonal variability, and cloud microphysics. Neptune presented itself to be an active world yet Uranus appeared bland in Voyager
images. Recent observations of Uranus have shown the planet to be more dynamically active, with a banded structure, clouds,
vortices, and transient plumes. In this talk we will explore the physical processes on these distant planets and examine how we
might further study weather on these planets using space- and ground-based instrumentation. A large proportion of the giant
worlds orbiting other stars are Uranus/Neptune-mass planets, yet Uranus and Neptune are poorly understood and are the missing
link between the gas giants and the terrestrial planets. The talk will also argue for their exploration in the coming decades.
Bio
Dr. Chris Arridge is a Royal Society Research Fellow and Lecturer at Lancaster University’s Department of Physics. He studies
the giant planets of our solar system, working particularly on Saturn using NASA's Cassini spacecraft. He’s also involved in
preparations for ESA’s JUICE mission to Jupiter and Ganymede, and is active in developing ideas for new mission concepts for
spacecraft to go to Uranus and Neptune. Some of his recent work has involved trying to understand how the Sun’s 11-year solar
cycle affects the magnetospheres of Jupiter and Saturn, trying to understand the origin of Saturn’s aurorae, examining how tiny
charged ice grains move near Saturn’s enigmatic moon Enceladus, and understanding how energy is stored in Saturn’s magnetic
field and then explosively released. Dr. Arridge studied Physics with Planetary and Space Physics at the University of Wales,
Aberystwyth, Applied Mathematics and Theoretical Physics at the University of Cambridge, and got his PhD in Space Physics
from Imperial College London. He worked at University College London’s Mullard Space Science Laboratory until taking up a
position at Lancaster University in 2014. You can follow him on Twitter (@ChrisArridge).
Professor Andrew Coates
Interplanetary Space Weather
Abstract
The effects of solar, energetic particle and electromagnetic events on the Earth and our technological systems are what is meant by
space weather in the terrestrial context. This is principally an application of the ‘science behind space weather’, solar-terrestrial
physics. Space weather forecasts are used by several sectors including satellite operators, airlines and utility distribution
organisations. On Earth, space weather forecasting is becoming routine (e.g. SWPC, Met office). In planetary science, we are still
exploring solar-planetary physics and space weather is less developed, and has only been defined and discussed relatively
recentl;y (Lilensten, Coates et al., 2014). Our exploration of the solar system is now leading us to consider space weather at other
objects as well (e.g. Jovian radiation belt predictions for JUICE). In this talk we will explore space weather at the Earth and other
planets, and consider the ‘state of the art’ in interplanetary space weather forecasting and effects.
Bio
Professor Andrew Coates gained a BSc in Physics from UMIST in 1978, and MSc (1979) and D.Phil. (1982) in plasma physics
from Oxford University. He is Deputy Director and Head of Planetary Science at UCL’s Mullard Space Science Laboratory
(MSSL). He is Principal Investigator for the PanCam instrument on the ExoMars 2018 rover. Other space mission involvements
include Cassini (leading the team providing the CAPS electron spectrometer), JUICE, Venus Express, Mars Express and Giotto.
Scientific interests include the solar wind interaction with planets and comets, planetary surfaces, plasma interaction with moons
including Titan, Enceladus, Ganymede and Europa, and space instrumentation.
Dr Manuel Grande
Europlanet Space Weather Service
Abstract
The Cospar Space Weather Roadmap and the new Europlanet Planetary Space Weather Service.
“Space weather refers to the variable state of the coupled space environment related to changing conditions on the Sun and in the
terrestrial atmosphere.”
The COSPAR/ILWS RoadMap
• focuses on high-priority challenges in key areas of research
• leading to a better understanding of the space environment and
• a demonstrable improvement in the provision of timely, reliable information
• pertinent to effects on civilian space- and ground-based systems,
• for all stakeholders around the world.
The Europlanet Planetary Space Weather Service
The RoadMap prioritizes those advances that can be made on short, intermediate and decadal time scales, identifying gaps and
opportunities from a predominantly, but not exclusively, geocentric perspective.
The overall objectives of the JRA will therefore be to review, test, improve and adapt methods and tools available within the
partner institutes in order to make prototype planetary event and space weather services operational in Europe at the end of the
programme
PSWS will make five entirely new ‘toolkits’ accessible to the research community and to industrial partners planning for space
missions:
1. General planetary space weather toolkit, as well as three toolkits dedicated to the following key planetary environments:
2. Mars (in support of the ESA ExoMars missions to be launched in 2016 and 2018),
3. comets (building on the expected success of the ESA Rosetta mission), and
4. outer planets (in preparation for the ESA JUICE mission to be launched in 2022).
5. Novel “event-diary” toolkit aiming at predicting and detecting planetary events like meteor showers and impacts.
Bio
Head of Solar System Physics Aberystwyth Univ; formerly Director of the Institute of Maths and Physics, Aberystwyth, visiting
professor at the Open University, and Warwick Univ.
PI for the X-ray spectrometers C1XS on Chandrayaan-1 and D-CIXS on SMART-1,
Co- PI on BepiColombo SIXS and Cluster/Rapid,
Co-I roles in JUICE, Bepicolombo(4 instruments), Cassini/CAPS and Cassini/CDA, Cluster/Peace, POLAR Cammice and
Ceppad, IMAGE MENA, Venus Express ASPERA4, Mars Express ASPERA3, SELENE
Executive chair of European Planetary Science Congress (EPSC). Chair Institute of Physics of Wales, Europlanet Coordinator for
Scientific Dissemination. Former President of European Geoscience Union for Planetary Science and served on council of Royal
Astronomical Society, Executive Committee of the French Centre for Plasma Physics Data (CDPP) and a number of ESA and
NASA committees.
UK representative on COSPAR, Vice Chair of COSPAR panel on Space Weather.
Dr Manish Patel
Weather measurements on Mars from orbit and landers
Abstract
The atmosphere of Mars displays the most similarity to the weather encountered on Earth, and thus presents a useful laboratory to
test our understanding of planetary and atmospheric processes. This talk will review the various observations of weather
throughout the history of Mars exploration, and will discuss the merits and difficulties of in situ meteorological observations. The
types of instruments used to make observations will be reviewed, and examples of terrestrial processes occurring on Mars will be
presented along with a summary of future observations intended for upcoming missions to further explore weather on Mars.
Bio
Manish Patel is a Senior Lecturer in Planetary Sciences at the Open University, working on instrumentation for Mars exploration
and radiative transfer modelling of the atmosphere. He also holds a Joint Appointment at RAL Space (Rutherford Appleton
Laboratory, Oxfordshire) where he undertakes planetary science-related research. He has worked on multiple space missions,
including Cassini-Huygens, Beagle 2/Mars Express, and is now Co-PI of the NOMAD instrument on the ExoMars Trace Gas
Orbiter, due for launch in March 2016 to map trace gases in the atmosphere of Mars.
Dr Stephen Lewis
Weather measurements from Mars entry/descent, and data assimilation
Abstract
One of the greatest challenges in Martian surface exploration is the successful execution of the entry, descent and landing
sequence onto the surface of the planet. The ESA ExoMars 2016 Entry, Descent and Landing Demonstrator Module, known as
Schiaparelli, is a vehicle carried by the ExoMars Trace Gas Orbiter, due to land on Mars (close to the equator and the prime
meridian) in October 2016. Schiaparelli will perform scientific measurements during the entry, descent and landing phases and a
surface meteorology package will operate for a few days. An entry and descent profile provides a rare in situ measurement of
martian atmospheric structure and is a valuable independent complement to more numerous thermal profiles, retrieved using
infrared remote sounding or radio occultation. Data assimilation is the process of combining observations with a numerical model
in order to produce an evolving estimate of the complete atmospheric state. The talk will illustrate its use in comparing the best
estimate of the Martian atmosphere made from other observations with previous entry profiles, interpolating to the correct time
and location of the spacecraft entry. It will also show how assimilation can be used to predict meteorological conditions for entry,
descent and landing using the example of NASA MSL/Curiosity in 2012.
Bio
Stephen Lewis is Deputy Head of the Department of Physical Sciences at The Open University. His research interests include the
dynamics of planetary atmospheres and the assimilation of spacecraft observations, primarily those of Mars. He is Co-Principle
Investigator for AMELIA entry, descent and landing science on ESA ExoMars 2016 Schiaparelli and is a Co-Investigator on Mars
Climate Sounder aboard NASA Mars Reconnaissance Orbiter. His work included making forecasts for NASA Mars Curiosity
landing in 2012. He is a lead developer of the ESA Mars Climate Database.
Dr Colin Wilson
Weather Measurements on Venus
Abstract
Measuring weather on Venus, with its surface temperatures of around 450°C, can be challenging. Venus is completely enveloped
in optically thick cloud, so remote sensing is limited to cloud-top altitudes and higher. Remote sensing carried out to date includes
thermal infrared measurements of temperature fields, and velocimetry by tracking cloud features at a several altitudes. In situ
meteorological observations, of pressure, temperature and wind velocities, have been carried out by descent probes and at the
surface of Venus. The cloud-level environment at an altitude of 55 km where the ambient temperature is ~ 20°C offers a more
benign environment for exploration, and was briefly explored by two Soviet helium balloons in 1984. The talk will give an
overview of these past measurements and briefly outline possible future measurements.
Bio
Colin Wilson is a Senior Research Fellow in the Atmospheric, Oceanic, and Planetary Physics group at Oxford University, with
interests in Mars and Venus atmospheric science. He designed anemometers for Beagle 2 and ExoMars Mars landers, and has
been Deputy Project Scientist for Venus Express since 2009
Dr. Mueller-Wodarg
Atmospheric structure and variability on Titan
Abstract
The atmosphere of Saturn’s largest moon Titan has been explored in great detail by the Cassini-Huygens mission, both in-situ and
remotely. As a slowly rotating body, Titan bears some similarities with Venus, while at the same time having much in common
with Earth as well, such as the main gas being molecular nitrogen. Uniquely, though, Titan is far from the Sun and thus more
challenging to understand since the dominance of solar heating in the inner solar system no longer applies, and processes such as
vertical coupling influence its structure to far greater extent, driving great variability especially in the upper atmosphere (above
600 km). This has made any understanding of Titan’s global structure far more difficult to obtain. In fact, Titan’s upper
atmosphere to-date is still poorly understood both in terms of density structure and temperatures. This talk will summarise the key
observations and simulation work, addressing on one hand the inherent difficulty posed by limited sampling in our observations
and on the other hand showing that weather on Titan may be truly unpredictable due to the inherent randomness of the dominant
drivers.
Bio
Dr. Mueller-Wodarg specialises in the study of planetary atmospheres. His key interests include their responses to solar forcing
and interaction with the plasma and magnetized space environment. He develops numerical atmosphere models, from 1-D to
global three-dimensional fluid models (“General Circulation Models”). His research has focused on Titan, Saturn, Venus and
Earth. Dr. Mueller-Wodarg was Team Leader for the Venus Express Atmospheric Drag Experiment, he is Science Team Member
for the Cassini Ion Neutral Mass Spectrometer and Co-PI for the Jupiter Icy Moon Explorer (JUICE) Radio and Plasma Wave
Investigation (RPWI).
Prof Giovanna Tinetti
Exoplanet Atmospheres
Abstract
It is now accepted that exoplanets are ubiquitous. However little is known about those planets we have detected beyond the fact
they exist and their location. For a minority, we know their weight, size and orbital parameters. How do we progress from
here? We have a host of questions for the next decade:
How did they form and evolve?
Are they habitable?
What are exoplanets made of?
What’s the weather like there?
The planetary parameters mass, radius and temperature alone do not explain the diversity revealed by current observations. The
atmospheric chemistry and dynamics of the exoplanets discovered is needed to trace back their formation history and evolution, as
it was the case for the Solar System.
Pioneering results were obtained through transit spectroscopy with Hubble, Spitzer and ground-based facilities, enabling the
detection of ionic, atomic and molecular species and of the planet’s thermal structure. With the arrival of improved or dedicated
instruments in the coming decade, planetary science will expand beyond the narrow boundaries of our Solar System to encompass
our whole Galaxy.
Bio
Professor Giovanna Tinetti has coordinated the research team on exoplanets at UCL since 2007. Awarded a PhD in Theoretical
Physics from the University of Turin, Giovanna is a Royal Society URF and has previously been a European Space Agency (ESA)
external fellow and NASA Astrobiology Institute/NRC fellow at Caltech/JPL.
Select appointments include Principal Investigator, European Research Council-funded programme “Exo-Lights”, editor
of American Astronomical Society DPS journal, ICARUS, and Institute of Physics Moseley medal 2011 for pioneering use of IR
transmission spectroscopy for molecular detection in exoplanet atmospheres. She is Principal Investigator of ARIEL, one of three
candidate-missions selected by ESA for its next medium class (M4) science mission, due for launch in 2026 and lead scientist of
the Twinkle space mission designed in the UK to be launched in early 2019.