ISSI Game Changer Online Seminar: News from the ISSI Team

Dear Friends of ISSI and the ISSI Game Changer Online Seminar!
The first season of the ISSI Game Changer Seminar Series “How missions change(d) our view of the Solar System, the Universe, and the Earth” ends with the end of this month of March. 

In four blocks since July 2020, we first covered missions such as Rosetta, Hayabusa II, and SOHO to solar system objects, and then astrophysical space telescopes such as Gaia, Integral, and the Hubble Space Telecope. In 2021 to date, we presented Earth observation missions such as SMOS, Cryosat and GRACE. The series will conclude on March 25 with a presentation on CFOSAT, a joint Chinese and French oceanography mission to understand ocean dynamics and climate variability. 

Before that, however, we present three more highlights: First, this Thursday, March 4, Prof. Stamatios Krimigis will report on the space odyssey of the two Voyager probes, which have now left the solar system and are cruising in interstellar space!  This will be followed on March 11 by a talk on the Apollo program and its scientific legacy presented by Prof. Jim Head a witness to the first manned landing on an extraterrestrial body. For March 18, we are soliciting a talk on an x-ray astrophysics mission. 

The Game Changers seminars will then take a break in April. In May we plan to resume the series. But this time the focus will not be on missions but rather on themes, “Ideas and Findings about the Solar System, the Universe and our Terrestrial Environment”, as we plan to call it. 

Foreseen are talks on topics like the origin of the Moon and of the Solar System, comparing it to other planetary systems. Spectroscopy of extrasolar planetary atmospheres will be on our agenda as well as Martian Seismology, the composition of the Sun, space weather and astrobiology. We will further look at the latest on the Hubble constant controversy, present new results on the merger history of the Milky Way, and offer exiting views on supermassive black holes – in our Galaxy and elsewhere. For our terrestrial environment we will keep an eye on problems related to climate and global change and their societal impact but also compare the Earth to its siblings in the solar system.  
We plan not to proceed in blocks this time but rather mix themes. An astrophysical topic can therefore immediately follow an environmental topic and precede a planetary topic.  

While in our present program we have been looking back at those missions that helped us better understand our world, for the new series we dare to look ahead to topics that we consider to be particularly promising for the future.
With our best regards and stay safe & tuned

Your ISSI Team 

Weight-Watching from Space – Tracking Changes in Earth’s Surface Water with GRACE & GRACE-FO with Felix Landerer (JPL, USA)

Earth’s distribution of water – in the form of ice, snow, soil moisture, groundwater, as well as lake and sea levels – is undergoing profound changes as the climate changes over seasons to decades. The original Gravity Recovery and Climate Experiment (GRACE) mission, launched in early 2002, has provided a unique and valuable data record to monitor and study changes in our global water cycle, and allowed precise determination of sea-level rise, polar ice-cap mass loss in Greenland and Antarctica, and large-scale water storage changes over land. By measuring small month-to-month changes in Earth’s gravity field, these observations provide a unique window into Earth’s evolving climate and water stores, and a glimpse into possible future impacts. The twin satellites of the GRACE Follow-On mission, in operation since June 2018, continue and extend the groundbreaking mass change data record from GRACE. In this presentation, I will describe the fascinating technology of contemporary gravity measurements from space, and present break-through science discoveries and every-day applications from the two GRACE missions, such as the variable ice mass loss over Greenland and Antarctica, and the emerging long-term trends of land water storage that impact water availability.

Felix Landerer is the Project Scientist for the joint NASA-GFZ GRACE Follow-On satellite mission at NASA’s Jet Propulsion Laboratory. He earned a degree in Geophysics from the University of Kiel, a doctorate in Physical Oceanography from the Max Planck Institute for Meteorology in Hamburg (Germany), and was a NASA Postdoctoral Fellow at JPL from 2008 to 2010. He explores and studies Earth’s constantly changing hydrosphere by using data from geodetic satellite observations (e.g., from GRACE(-FO) and ocean altimeters), and geodetic ground observations (e.g., GPS, tide gauges) to understand global and regional sea level variations and underlying processes, and to provide relevant data to track water redistribution and availability (e.g., ice mass, aquifer storage) in a changing climate. 

Seminar was recorded on February 25, 2021



Observing our Magnetic World: When Theory Follows Space Measurements with Mioara Mandea (CNES, France)

Over the last decades, the convergence of novel approaches has led to substantial progress in our understanding of the Earth’s magnetic field characteristics and properties. These advancements have been possible due to the high quality geomagnetic data, which have been obtained either from ground magnetic observatories or from dedicated satellite missions. A radical move took place in 1980, after the launch of the very first satellite carrying a vector magnetometer to measure the full magnetic field, MAGSAT. The state-of-the-art has dramatically changed with measurements obtained from the Oersted, CHAMP, SAC-C satellites, and mostly with the recent ESA Swarm mission, launched in 2013. An overview of these space missions and of our present understanding of the geomagnetic field is given, covering commonly accepted and some of the more controversial aspects. The geomagnetic observations have been crucial in developing new insights and new theories, and a few aspects of the Earth’s deep and shallow processes grasped by the magnetic field are presented, in closest relation with some other geophysical data.

Mioara Mandea is currently the Programme Manager for Solid Earth at the Directorate for Innovation, Applications and Science at Centre National d’Etudes Spatiales in Paris (French Space Agency). Over recent decades, she has been involved in many activities of the International Association of Geomagnetism and Aeronomy (both Secretary General and President), European Geosciences Union (General Secretary and Chair of Outreach Committee), American Geophysical Union (Chair of Education Award Committee), International Space Science Institute (Chair of Science Committee), Commission for the Geological Map of the World (President of the Sub-commission of Geophysical maps), to name the most important. Mioara Mandea has published more than 250 papers, has been involved in organising many workshops and conferences, and has also led several multi-partner research projects or work packages within projects at different national and EU levels. Mioara Mandea is member of the Academy of Romanian Scientists, Academia Europea, Académie Royale de Belgique, Russian Academy of Science. She received the International Award of AGU, the Petrus Peregrinus medal of EGU, and the prestigious French “Ordre National de Mérite” (more information on

Seminar was recorded on February 18, 2021 

SMOS, Soil Moisture and Sea Surface Salinity with Yann Kerr (CESBIO, France)

SMOS, a L Band radiometer using aperture synthesis to achieve a good spatial resolution, was successfully launched on November 2, 2009. It was the first instrument to operate operationally at L band – the first instrument thus to deliver direct estimates of surface soil moisture and sea surface salinity – and the first interferometer flown in space. A true game changer! SMOS carries a single payload, an L band 2D interferometric, radiometer in the 1400-1427 MHz protected band. This wavelength penetrates well through the vegetation and the atmosphere is almost transparent enabling to infer both soil moisture and vegetation water content, the so called L-VOD. SMOS achieves an unprecedented spatial resolution of 50 km at L-band maximum (43 km on average) with multi angular-dual polarized (or fully polarized) brightness temperatures over the globe and with a revisit time smaller than 3 days. SMOS has been now acquiring data for almost 12 years. The data quality exceeds what was expected, showing exceptional sensitivity and stability. The data is however impaired by man-made emission in the protected band, leading to degraded measurements in several areas including parts of Europe and China. Many different international teams are now addressing data use in various fields. We have now acquired data over a number of significant “extreme events” such as droughts and floods giving useful information of potential applications and are now working on the coupling with other models and or disaggregation to address soil moisture distribution over watersheds. Furthermore, we are also concentrating efforts on water budget and regional impacts. From all those studies, it is now possible to express the “lessons learned” and derive a possible way forward. This seminar thus gives an opportunity to present the achievements of the SMOS mission, a description of its main elements, and a taste of the results including performances at brightness temperature as well as at geophysical parameters level and how they are being put in good use in many domains.

Yann Kerr’s fields of interest include the theory and techniques for microwave and thermal infra-red remote sensing of the Earth, with emphasis on hydrology, water resources management and vegetation monitoring. He is involved in many space missions from conception to launch, and post-launch validation as well as to derivation of applications including EOS principal investigator of interdisciplinary investigations from 1990-1999 and PI of the precursor of the use of Scatterometer (SCAT – on board of the European Remote Sensing (ERS) satellite) data over land, Co-investigator on Interface Region Imaging Spectrograph (IRIS), Optical Spectrograph and Infra-red Imager System (OSIRIS), and Hydrosphere State (Hydros) Satellite Mission for NASA. Yann Kerr was science advisor for Multifrequency Imaging Microwave Radiometer (MIMR) and Land Surface Temperature Mission (LSTM) and Co-I on Advanced Microwave Scanning Radiometer (AMSR). In 1990, he developed interferometric concepts applied to passive microwave Earth observation and was subsequently the science lead on the Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) project for European Space Agency (ESA) with Matra Marconi Space (MMS) and Observatoire Midi-Pyrénées (OMP). In 1997, he first proposed the development of the SMOS Mission that was eventually selected by CNES and ESA in 1999 and launched in 2009 with the incumbent as the SMOS mission Lead-Investigator and Chair of the Science Advisory Group. Yann Kerr also leads SMOS science activities coordination in France and organised all the first SMOS Science workshops and is a member of the Soil Moisture Active Passive (SMAP) Science team. Yann Kerr was deputy director of LERTS and CESBIO and Director of CESBIO. 


Seminar was recorded on February 11, 2021

CryoSat – A Decade of Polar Altimetry with Andrew Shepherd (University of Leeds, UK)

CryoSat-2 is ESA’s first satellite mission dedicated to measuring changes in the cryosphere and its measurements have transformed our capacity to study the polar regions. Thanks to CryoSat-2, we now have an altogether new appreciation of how Earth’s ice sheets, ice shelves, sea ice, glaciers, and polar oceans are evolving. As global temperatures have risen, so to have rates of snowfall, ice melting, and sea level rise, and each of these changes impacts upon the neighbouring land, marine, and atmospheric environments. CryoSat-2 measurements are now central to our awareness and understanding of Arctic and Antarctic environmental change; a case in point is the marine ice sheet instability that is underway in West Antarctica, widely understood to be among the greatest contemporary imbalances in the climate system, whose evolution has been charted in satellite altimeter data since its onset. In this presentation, Andrew Shepherd will introduce the CryoSat-2 mission concept, describe the technical advances that have improved our capability to monitor land ice, sea ice, and the polar oceans, and review a series of flagship studies that have allowed both long-standing and unanticipated scientific problems in cryospheric research to be solved.

Andy Shepherd is Professor of Earth Observation at the University of Leeds, Director of the NERC Centre for Polar Observation and Modelling, Principal Scientific Advisor to the European Space Agency CryoSat satellite mission, and co-leader of the ESA-NASA Ice Sheet Mass Balance Inter-comparison Exercise. He uses satellites to study the physical processes of Earth’s climate, and his main contributions to science have involved developing remote observations of the cryosphere, with particular emphasis on radar interferometry and radar altimetry. He has also led field campaigns in Europe, Africa, Greenland and Antarctica, to calibrate and validate satellite missions. Andrew was educated in the Department of Physics and Astronomy at the University of Leicester, and prior to working at Leeds he has held academic posts at University College London, at the University of Cambridge, and at the University of Edinburgh. He has co-authored over journal 100 papers that are often reported in the media, and he regularly contributes to broadcast documentaries such as the BBC’s Blue Planet 2 and Climate Change: the Facts. Andrew was awarded a Philip Leverhulme Prize in 2008 and a Royal Society Wolfson Research Merit Award in 2014.


Seminar was recorded on February 4, 2021. 

“CHEOPS – the CHaracterizing ExOPlanet Satellite” Pro ISSI Talk with Andrea Fortier

“CHEOPS – the CHaracterizing ExOPlanet Satellite”

Pro ISSI talk with Andrea Fortier, Instrument Scientist, CSH (CHEOPS), University of Bern , Switzerland

In 1995, two Swiss astronomers discovered the first exoplanet around a solar-like star. Since then, ground and space surveys have discovered more than 4000 exoplanets and the number continues to increase. The diversity seen in their masses, radii and orbital characteristics has opened a new and dynamical community in astronomy: the exoplanetary science. With a critical mass of researchers in a large variety of topics and a statistically significant number of confirmed objects, the time for the characterisation of these new worlds has come: what is their composition?, how do they form?, could they harbour life?

In December 2019, with the aim of finding hints to answer these questions, the CHaracterising ExOplanet Satellite (CHEOPS) was launched from French Guyana. CHEOPS was selected in 2012 as the first ESA Small Mission, with Switzerland leading a consortium of 11 European countries. After three months of in-orbit commissioning, CHEOPS started its nominal operations at the end of March 2020 acquiring images that allow for precise measurements of the exoplanets’ radii through the transit photometry technique.

In this talk CHEOPS primary objectives, its goals and first scientific results are presented. Furthermore, an overview of the construction phase, the challenges faced while building a mission in a short time and the current operation of the satellite are a part of this talk.

This presentation was recorded on January 20, 2021.

Prof. em. Dr. Hans Balsiger

Hans Balsiger (picture taken on the ISSI Annual Dinner 2015)
Hans Balsiger (picture taken on the occasion of the ISSI Annual Dinner 2015)

With great sadness, ISSI heard of the passing away of Prof. Hans Balsiger, former Director of the Physics Institute of the University of Bern and Professor of Experimental Physics. Prof. Balsiger helped found the institute and served on the ISSI Science Committee and the Board of Trustees for twenty years, between 1995 and 2014. He was a true friend of the institute and always a great supporter. His advice was highly appreciated. 


ISSI and its staff will miss him greatly!

Our thoughts are with his family and friends.



From Satellite Observations and Atmospheric Modeling to Air Quality Forecasts with Guy Brasseur (Max Planck Institute for Meteorology, Hamburg, Germany)

According to the World Health Organization, poor outdoor air quality is responsible for the premature death of about 4 million people each year. From a health point off view, air pollution is currently the worse environmental problem facing humanity, particularly in low- and medium income countries. In the last decades, remote sensing observations from space have provided unique information on the abundance, annual variations and long-term trends of chemical species including ozone in the stratosphere. Today, a grand and difficult challenge is to probe the troposphere at high spatial and temporal resolution to monitor air quality at the regional and even local scales. The TROPOMI instrument on Sentinel 5p, for example, provides unique information on nitric oxide, a major pollutant emitted by traffic, industrial operations, energy generation, etc. while several forthcoming geostationary satellites including the Korean GEMS mission, just launched, will measure chemical species at a  spatial resolution than higher than most model resolutions.

Space observations and in situ monitoring of chemical species in the atmosphere together with information about surface emissions and atmospheric chemical and physical processes provide the basis for the development of air quality forecast systems. An important concern from policymakers is the attribution of the sources responsible for our pollution episodes. The seminar will present an integrated view on these questions.

Guy Brasseur is a Senior Scientist and former Director at the Max Planck Institute for Meteorology in Hamburg, Germany. He is also a Distinguished Scholar and a former Associate Director at the National Center for Atmospheric Research (NCAR) in Boulder, CO, USA. He is a Visiting Professor at the Polytechnic University of Hong Kong. Brasseur was the Chair of the International Geosphere Biosphere Program and more recently of the World Climate Research Program. His interests include atmospheric chemistry and climate change. His early focus was first on stratospheric ozone and chemistry of the upper atmosphere. He has contributed to the development of global atmospheric chemistry models and climate models.

Seminar was recorded on January 21, 2021

Reshaping Earth: How the TOPEX and Jason Satellites Revolutionized Oceanography and Redefined Climate Science with Josh Willis (JPL, USA)

Humans are reshaping the Earth. Not just the climate of Earth, but the planet itself.  As the Earth warms due to human interference with the climate, the oceans rise. And covering more than two thirds of the planet’s surface it means the rising oceans are literally changing the shape of the planet we call home. And since the early 1990s, a single series satellites has captured this change with unbelievable accuracy. Built to measure changes in ocean currents, our sea level satellites have revolutionized our understanding of the oceans and now provide one of the most important records of how fast our climate is changing. The unprecedented success of these missions has led to the development of the Jason-CS Mission, which includes the recently launched Sentinel-6 Michael Freilich satellite. This US-European collaboration includes two satellites, launched 5 years apart, and will guarantee another full decade of sea level observations. In addition, the upcoming SWOT mission will improve the resolution of sea level measurements, allowing oceanographers to explore new ocean physics.  SWOT will also provide unprecedented coverage of lake and river observations, likely touching off a similar revolution in the field of hydrology.

Josh Willis is the lead NASA scientist for the US and European Jason satellite missions that measure sea level, and the recently launched Sentinel-6 Michael Freilich satellite that will help carry this legacy through the rest of the coming decade.  Willis is an expert in sea level rise and its causes.  He is also the lead scientist for NASA’s airborne mission Oceans Melting Greenland (OMG for short!).  He enjoys using comedy to communicate about climate change has has been known to tell the occasional or sing a song to help people understand why the climate is changing.

“You take a bunch of weather and you average it together and you’re doing the Climate Rock!” Climate Elvis meets a curious 11-year old and answers her question about climate with a song.

Climate Rock” Josh Willis (aka Climate Elvis) Music by Kevin Stafford Lyrics by Josh Willis Produced and Mixed by Mike Wojtkiewicz Backup Vocals by Denah Angel, Shayla Tharp, Jhanna Nocon, and Lizze Gordon Portuguese Captions by Américo Ambrózio and Rui Ponte. Script by Lizze Gordon and Josh Willis, Directed by Lizze Gordon.  Animation: Joe Homokay.

Seminar was recorded January 14, 2021