“The Digital Twin of Earth” with Peter Bauer (ECMWF, Germany)

Digital twin technologies – already established in engineering – are becoming increasingly interesting for applications in Earth sciences. Digital twins offer effective tools for dealing with the dramatic impacts of climate change and extremes on our society. They allow exploring the vast amounts of data produced by numerical models and Earth observations to identify causes and effects of environmental change on water, food, energy and health management, and for finding pathways for a more sustainable future. The enormous computing and data handling challenges for Earth-system twins can only be overcome by substantial investments in super-computing and machine learning. These are addressed by the European Commission flagship activity Destination Earth (DestinE). DestinE was launched in 2021 with a projected lifetime of 7-10 years and is implemented by the European Space Agency (ESA), the European Centre for Medium-Range Weather Forecasts (ECMWF) and the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT). The project is entering its 2nd phase in mid 2024 and is already delivering first examples of digital-twin technology to selected users.

Peter Bauer received his PhD in meteorology from the university of Hamburg, Germany, in 1992. He joined the German Space Agency (DLR) in 1989, but was also awarded guest scientist positions at the National Atmospheric and Oceanic Administration (NOAA) and the National Aeronautics and Space Administration (NASA) in the USA, and the Institut Pierre Simon Laplace (IPSL) in France. He joined the European Centre for Medium-Range Weather Forecasts (ECMWF) in 2000, where he headed the units for satellite data assimilation and model development before becoming the deputy director of research. He implemented the Scalability Programme preparing the forecasting system for emerging super-computing technologies. He coordinated the European flagship proposal ExtremeEarth leading to his appointment as the ECMWF director for Destination Earth. During his career, Peter Bauer was a member of numerous strategic advisory committees for national meteorological services, WMO and space agencies. He retired from ECMWF in mid 2023.

Webinar was recorded on February 29, 2024 


“Exoplanet Atmospheric Spectroscopy in the Era of JWST” with David Sing (Johns Hopkins University, USA)

We are now more than a full year into the era of JWST, NASA’s flagship observatory and successor to the Hubble Space Telescope. Exoplanet characterization has historically been dominated by space-based facilities, and the new infrared capabilities of JWST are uncovering the atmospheres of exoplanets in an unprecedented way. The chemical signatures of planets are being actively probed and detected, with an array of new chemical species now detectable including oxygen, carbon and nitrogen-bering molecules. This opens up spectral constrains to the rich atmospheric chemistry ongoing in a wide range of planetary types, temperatures, and metallicities. In this talk, the speaker will discuss some of the outstanding questions in the exoplanet field and how the atmospheric chemistry can help address these questions. He will also present new transit and phase curve results from ongoing JWST programs, including a Neptune and Jupiter mass planet discussing the implications of the chemistry and atmospheric physics of these planets.

David Sing is the Bloomberg Distinguished Professor of Astrophysics at the Johns Hopkins University, in the Departments of Physics and Astronomy as well as Earth and Planetary Sciences. David Sing is a worldwide expert of exoplanet science, with special interest in the detection and characterization of exoplanets, the physics and chemistry of their atmospheres, and comparative  exoplanetology studies. His research involves both observations and theoretical spectral retrieval modeling.He uses primarily  transit method data collected  by the Hubble Space Telescope and the James Webb Space Telescope to make transmission, emission and phase curve panchromatic measurements for planets from super-Earth to Neptune and Jupiter sizes.

Webinar recorded on January 25,  2024


“Genetically Modified Galaxies” with Andrew Pontzen (UCL, UK)

Computer simulations of the universe have been in common use since the 1980s, and are now a vital tool in helping us interpret data from increasingly powerful telescopes. Amongst other things, simulations have helped establish the case for dark matter and dark energy, and have been key to creating a broad consensus around the idea that galaxies start small and grow over time through merging. The speaker reviews in outline how these simulations work, and highlight that a key difficulty in understanding their results is to untangle cause and effect. For example, the observed diversity of different galaxy sizes, shapes and colours can be reproduced in a statistical sense, but there is still considerable uncertainty around which causal processes give rise to this diversity. The speaker explains how exerting careful experimentation with the initial conditions for our simulations, which represent conditions shortly after the ‘big bang’, we can start to address these uncertainties. We call this technique ‘genetic modification’, since it loosely corresponds to controlling the genes of our virtual galaxies, to see how the galaxies mature and develop in response. This in turn helps to build a more complete physical picture of how galaxies mature over time, with carefully quantified uncertainties. The speaker discusses how such efforts are vital to making sense of new observations from cutting-edge and future facilities like Gaia, JWST, ELT, SKA and LISA.

Andrew Pontzen is a professor of cosmology at University College London (UCL), and is currently principal investigator of the ERC consolidator project GMGalaxies. His research concerns how structures formed in our universe, using a combination of theoretical and computational advances including the ‘genetic modification’ technique which he pioneered and which will be the focus of this talk. He was the founding co-director of the UCL Cosmoparticle Initiative which fosters interdisciplinary research, and has received multiple awards for his research and communication.  He is the author of The Universe in a Box which is a non-specialist book focussing on the role of simulations in cosmology and beyond, recently published to critical acclaim.

Webinar was recorded on November 30, 2023

“Telescopes on the Moon: The Next Decades” with Joseph Silk (John Hopkins University and IAP, France)

The lunar surface allows a unique way forward, to go well beyond current limits in astronomy and cosmology. The far side provides a unique radio-quiet environment for probing the dark ages via 21 cm interferometry to seek elusive clues on the building blocks of the galaxies and the  nature of inflation.  Optical interferometers will eventually provide up to  a few microarsecond  imaging of the nearest exoplanets.  Far-infrared telescopes in cold and dark polar craters will probe the cosmic microwave background  radiation back to the first months of the Big Bang. 

Joseph Silk is Homewood Professor of Physics and Astronomy at the Johns Hopkins University in Baltimore and a researcher at Institutd’Astrophysique de Paris and Service d’Astrophysique, CEA Saclay in France. He is also a Senior Fellow at the Beecroft Institute for Particle Astrophysics and Cosmology at the University of Oxford. He is a Fellow of the Royal Society and a member of the National Academy of Sciences and the American Academy of Arts and Sciences. Silk has received many awards, including the 2011 International Balzan Foundation Prize. He has published more than 700 articles and several popular books. Most of his scientific research is related to cosmology and particle astrophysics. His specialties include the cosmic microwave background, the fossil radiation from the beginning of the universe; formation of the galaxies; and exploration of the nature of the dark matter that is the dominant form of matter in the observable universe. He discovered the Silk damping mass, a key component of the Big Bang theory of modern cosmology, and his predictions of the associated damping of cosmic microwave background radiation fluctuations have been verified by several recent experiments.

Webinar was recorded on October 26, 2023

“Essential Climate Variable (ECV) Products from Satellite Gravimetry” with Adrian Jäggi (University of Bern, Switzerland)

Satellite gravimetry missions such as the on-going GRACE Follow-On (FO) mission, the planned GRACE-FO continuation mission as well as a Next Generation Gravity Mission (NGGM) that will form together with the GRACE-FO continuation mission the Mass-change and Geosciences International Constellation (MAGIC), are unique observing systems to measure the tiny variations of the Earth’s gravity field. Time-variable gravity derived by satellite gravimetry provides integrative measures of Terrestrial Water Storage (TWS) variations on a regional to global scale. Given the large interest of the scientific community to understand the processes of changes in TWS, comprising all the water storage on the Earth’s continental areas in frozen and liquid state, including ice caps, glaciers, snow cover, soil moisture, groundwater and the storage in surface water bodies and the interaction with ocean mass and sea level, TWS was adopted as a new Essential Climate Variable (ECV) in the implementation plan 2022 of the Global Climate Observing System (GCOS).

In this talk an overview of the underlying principles of the challenging satellite gravimetry data analysis is given and selected key scientific results and products are highlighted. A special focus is on European and international initiatives such as the Combination Service of Time-variable Gravity Fields (COST-G) of the International Association of Geodesy (IAG) and the H2020 project Global Gravity-based Groundwater Product (G3P) to exploit this unique observable in order to eventually derive the ECV Groundwater.

Groundwater is a most fundamental resource, but there is no service available yet to deliver data nor is there any other data source worldwide that operationally provides information on changing groundwater resources in a consistent, observation-based way with global coverage. By capitalizing from TWS derived from satellite gravimetry and from other satellite-based water storage compartments the H2020 project G3P established a prototype to provide groundwater storage change for large areas with global coverage that is planned to be included as a cross-cutting extension of the existing service portfolio of the European Union’s Earth Observation programme Copernicus.

Adrian Jäggi is the Director of the Astronomical Institute of the University of Bern (AIUB) in Switzerland. He is a Fellow of the International Association for Geodesy (IAG) and was president of IAG’s Commission 2 (Gravity Field) between 2019 and 2023. He initiated several international scientific projects in the field of space geodesy, among them projects funded by the Horizon 2020 Framework Program for Research and Innovation and the European Research Council, and is the founding Chair of IAG’s Combination Service of Time-variable Gravity fields (COST-G).

Webinar was recorded on September 28, 2023

“Combining Exoplanet Measurement Techniques to Discover, Weigh and Characterize Cold Gas Giants” with Emily Rickman (Space Telescope Science Institute, Baltimore, USA)

Giant planets and brown dwarfs at an orbital separation great than 5 AU are important puzzle pieces needed for constraining the uncertainties that exist in giant planet formation and evolutionary models that are plagued by a lack of observational constraints. In order to observationally probe this mass-separation parameter space, direct imaging is necessary but faces the difficulty of low detection efficiency. To utilize the power of direct imaging, pre-selecting companion candidates with long-period radial velocities, coupled with astrometry from Hipparcos and Gaia, provide a powerful tool to hunt for the most promising candidates for direct imaging. Not only does this increase the detection efficiency, but this wealth of information removes the degeneracy of unknown orbital parameters, leading to derived dynamical masses which can serve as benchmark objects to test models of formation and evolution. With the recently launched JWST, as well as upcoming facilities like the ELT and the Nancy Grace Roman Space Telescope, observing time is valuable and the strategy of direct imaging needs to be re-defined to pre-select targets and characterize the companions that we do discover.

Emily Rickman is a Science Operations Scientist for the European Space Agency (ESA) based at the Space Telescope Science Institute in Baltimore, Maryland. Emily Rickman is a member of the Hubble Space Telescope team providing support to the STIS instrument as well as a project-level member of the JWST Telescope Scientist Team for coronagraphy, and the JWST High-Contrast Imaging ERS Team. Emily Rickman earned her doctorate in Astronomy and Astrophysics from Geneva Observatory in 2020, where she also spent some time as a postdoctoral researcher. She was then awarded a fellowship with the European Space Agency at STScI. Prior to earning her PhD, Emily Rickman graduated from the University of Sheffield with a first-class Masters degree with honors in Physics and Astrophysics, including spending one year as a researcher at the Australian National University.

Webinar was recorded on August 31, 2023

Sun, Climate and Ozone: 1850–2100 with Judith Lean (University of Colorado, USA)

As Earth’s energy source and a variable star, the Sun has been credited over the past century with causing climate change that is a significant fraction of industrial-era warming… or so small as to be undetectable. Now, with more than forty years of space-based observations of solar irradiance and multiple geophysical quantities, and extensive advances in modelling solar irradiance and terrestrial variability, we can clarify with greater certainty the extent to which the Sun alters Earth’s environment, especially since 1850. This talk summarizes current observational evidence for the Sun’s role in global climate change and ozone-depletion recovery, and discusses the scientific (and societal) consequences of faulty detection and attribution.

Judith Lean is a senior scientist at the United States Naval Research Laboratory. She is a solar and climate scientist and her research focuses on the mechanisms and measurements of variations in the Sun’s radiative output at all wavelengths, and the effects of this variability on Earth, from the surface to space. Past Co-Investigator on UARS and SORCE missions. Testified to the US Congress on the role of solar output variations in climate change; chaired the National Research Council’s (NRC) Working Group on Solar Influences on Global Change. Served on multiple NSF, NOAA, NRC and NASA advisory committees. Author of more than 150 published papers and 300 presentations. Model reconstructions of solar irradiance variability have been used in multiple climate change simulations, including IPCC. American Geophysical Union Fellow (2002), US National Academy of Sciences member (2003), American Philosophical Society member (2013). Presidential Rank Award for Meritorious Senior Professional (2011).

Webinar is recorded in June 29, 2023

“Asteroid Deflection and Exploration: Successes and Challenges” with Patrick Michel (CNRS, France)

The DART (NASA) and Hera (ESA) missions offer the first fully documented asteroid deflection test based on the kinetic impactor technique, allowing us to check and potentially validate our impact numerical models at the real scale of an asteroids. DART succesfully tackled the challenge to deflect the small moon, called Dimorphos, of the binary asteroid Didymos on September 26th, 2022, causing a decrease of the orbital period of Dimorphos around its primary. But many questions remain that will be answered by the Hera mission. Moreover, images sent by space missions to asteroids reveal that these objects are not simple rocks in space but very complex small geological world, whose response to external actions in their low gravity environment challenges our intuition. What did we learn from past missions, what are the challenges, the surprises and the remaining uncertainties? How will Hera measure the outcome of the DART impact and the properties of the asteroid? This presentation will address these questions that are not only relevant for planetary defense but also for the scientific understanding of those small worlds, which are the remnants of the bricks that formed our planets, and of the impact process, which plays a major role in all phase of our Solar System history.

Patrick Michel is Director of Research at CNRS (French Scientific Research National Center) and leads the Planetology team of the Lagrange laboratory at the Côte d’Azur Observatory (Nice, France). He is also Global Fellow (Professor with a foreign permanent affiliation) of the University of Tokyo (School of Engineering, Japan). With more than 220 publications in international peer-review journals, he develops numerical simulations of the impact process between asteroids, which reproduced for the first time real asteroid families, and of their surface and interior in their low-gravity environment.

Webinar was recorded on June 1, 2023

“Climate Change from Space” with Gavin A. Schmidt (Goddard Institute for Space Studies, NASA, USA)

NASA interest in climate change goes back decades, and the now 50-year long record of remote sensing has provided clear evidence of ongoing change, as well as process-based information that inform the climate models that help us explain what is happening (and what will likely happen in the future). This talk reviews the highlights of NASA’s work in this area across multiple methods as well as some of the ongoing challenges.

Gavin A. Schmidt is the Director of the NASA Goddard Institute for Space Studies in New York and was the acting Senior Climate Adviser to the NASA Administrator in 2021. He currently works on the simulation of climate in the past, present, and possible futures and has over 150 peer-reviewed publications. He was the author with Joshua Wolfe of “Climate Change: Picturing the Science” in 2009, and in 2011 was the inaugural recipient of the American Geophysical Union (AGU) Climate Communication Prize. He is a fellow of the AGU and American Association for the Advancement of Science and his 2014 TED Talk on climate modeling has been viewed over a million times.

Webinar was recorded on April 27, 2023

“Life on Miller’s Planet: The Habitability Zone Around Supermassive Black Holes” with Jeremy D. Schnittman (NASA, GSFC, USA)

In the blockbuster science fiction movie “Interstellar” (Warning: spoiler alert!), a team of intrepid astronauts set out to explore a system of planets orbiting a supermassive black hole named Gargantua, searching for a world that may be conducive to hosting human life. With Kip Thorne as science advisor, the film legitimately boasts a relatively high level of scientific accuracy, yet is still restricted by Hollywood sensitivities and limitations. In this talk, we will discuss a number of additional effects that may be important in determining the (un)inhabitable environment of a planet orbiting close to a giant, accreting black hole like Gargantua. In doing so, we hope to reach a greater understanding of the fascinating physics governing accretion, relativity, astrobiology, dark matter, and yes, even gravitational waves.

Jeremy D. Schnittman joined the Astrophysics Science Division at NASA Goddard in 2010 following postdoctoral fellowships at the University of Maryland and Johns Hopkins University. His research interests include theoretical and computational modeling of black hole accretion flows, X-ray polarimetry, black hole binaries, gravitational wave sources, gravitational microlensing, dark matter annihilation, planetary dynamics, resonance dynamics, and exoplanet atmospheres. He has been described as a “general-purpose astrophysics theorist”, which he regards as quite a compliment.

Webinar was recorded on March 30, 2023