Interview with Johannes Geiss Fellow Sandra Chapman

Sandra Chapman is the Johannes Geiss Fellow 2023 and is a plasma physicist working on problems in astrophysics and in the laboratory. She is currently Professor of Physics and Director of the Centre for Fusion, Space and Astrophysics at the University of Warwick and adjunct Professor at UIT. Her early work on nonlinear plasmas was recognised with the COSPAR Zeldovich Medal (commission D) and the EGS Young Scientists’ Medal. She was selected to give the 2014 Royal Astronomical Society James Dungey Lecture and the 2020 Ed Lorenz Lecture at the Fall meeting of the American Geophysical Union. Sandra is part of a team awarded a 2021 Lloyd’s of London Science of Risk Prize. She has been awarded the 2022 Royal Astronomical Society Chapman Medal and the 2024 Johannes Alfvén Medal of the European Geosciences Union. In the following paragraphs she answers a few questions – asked by Roland Hohensinn, ISSI Post Doc – about her research. Roland Hohensinn is postdoctoral fellow in Earth Sciences and Data scientist. He does research on uncertainty quantification from satellite remote sensing data, with a focus on space geodetic techniques (GRACE/GRACE-FO terrestrial water storage, long-term GPS ground motions).

Roland Hohensinn: Sandra, please explain us the beauty of your science.

Sandra Chapman: I have been privileged to be able to work across a variety of topics under the general heading of ‘plasma physics’. Plasmas are not only ubiquitous in the universe, they are also fundamentally non-linear and, in space and astrophysical systems particularly, are far from equilibrium. So our study of plasma physics touches upon some of the deepest physics questions- how does entropy increase in a collisionless plasma? How do we go from physics which on the microscale is reversible, but on the macroscale, irreversible, without collisional dissipation? How are particles accelerated, how do energy and momentum flow between fields and particles?

The models and mind-pictures that we use are based on the equations of Maxwell, Lorentz, Liouville et al, and these are fundamentally beautiful in their structure and expression. I am a great fan of ‘the truth is usually beautiful’ approach to physics.

Sandra Chapman, Johannes Geiss Fellow 2023, and Roland Hohensinn, ISSI Post Doc

Roland Hohensinn: Which transformations you see your field undergoing at the moment?

Sandra Chapman: Thinking about space plasma physics, I think this is a particularly exciting, and challenging time. When I was beginning my physics career, the norm was to have access to the data from a single satellite and to look in detail at single time-series, perhaps to try some conjugate study with ground based observations or a second satellite. Plasma simulations were highly restricted in dimension and could only capture one physical scale of interest. Now we are in a data-rich era with imaging, multiple satellites and hundreds of ground based observations, all at unprecedented spatial and temporal resolution, but these observations are not homogeneous. Alongside this, we now have the capability to build and run computer simulations which evolve the fully non-linear plasma physics across multiple physical space and timescales. We need to think of new ways to extract, visualize, interrogate and compare the relevant information from this data, both from observations and simulations. There are many new tools for this that are well-established in other fields:  networks, machine learning, AI, but the critical first step in this process is in formulating the physics questions to be asked of the data and building this into the analysis pathway, otherwise it is ‘garbage in, garbage out’. I don’t think that human physicists will be out of a job anytime soon!

Roland Hohensinn: How do you see the current and future role of ISSI in space sciences?

Sandra Chapman: It is one of life’s ironies that the more a science career progresses, the less time there is available to actually do science. So institutes like ISSI are an invaluable refuge that combine time to think, with opportunities to discuss. Physics has no borders and space science in particular is intrinsically international. ISSI in particular offers the flexibility to co-ordinate international teams on new topics. The ways in which we communicate our science, to each other, and to the wider public, are also changing rapidly and ISSI I think is well positioned to play a key role in this.

The Johannes Geiss Fellowship (JGF) is established to attract to ISSI – for limited duration visits – international scientists of stature, who can make demonstrable contributions to the ISSI mission and increase ISSI’s stature by their presence and by doing so will honor Johannes Geiss for his founding of ISSI and his contributions to ISSI, and for his many contributions to a broad range of space science disciplines.

Job Posting: Postdoctoral Position Opening in the Multi-messenger Astronomy related to CTA

The International Space Science Institute (ISSI) in Bern, Switzerland, invites applications for a

Postdoctoral Position Opening
in the Multi-messenger Astronomy related to CTA

for one year, renewable, ideally starting in January 2024, or to be negotiated. The Postdoctoral Fellow position is within the Cherenkov Telescope Array (CTA) project and in close collaboration with the University of Geneva. The CTA is the next-generation ground-based gamma-ray observatory featuring tens of telescopes located at two sites in both hemispheres. It will allow probing the high energy cosmic ray sources with unprecedented sensitivity and angular resolution, in the energy domain from tens of GeV to hundreds of TeV.

The University of Bern and Geneva group lead the Calibration Pipeline subsystem of the CTA Data Processing and Preservation System (DPPS) and contribute to the development of the Data Quality Pipeline. The DPPS is a software system responsible for the reconstruction, processing, quality monitoring, and preservation of data products of the CTA.

The successful candidate should have received a Ph.D. within the last five years and is expected to work on the development and implementation of the data quality monitoring tools, and related software infrastructure.

Required Qualifications

  • Experience with the Data Quality Monitoring in the domain of (astro)particle physics
  • Strong knowledge of Python
  • Familiarity with version control systems (Git/GitLab)
  • 0Ph.D. in Physics/Astronomy/Computer Science or related discipline

Preferred Qualifications

  • Experience with UI design
  • Experience in data analysis in the field of very high-energy gamma-ray astrophysics
  • Experience in web application development

Salary and conditions of employment will be similar to those provided by the Swiss National Science Foundation (SNSF salary ranges). Nationals from ESA Member States are especially encouraged to apply.

Further information may received by contacting Prof. Maurizio Falanga ( or Prof. Teresa Montaruli (

All applications must be received by ISSI no later than January 12, 2024.

Full Job Announcement and Applications >>

Michael R. Meyer has been selected as the Johannes Geiss Fellow 2024

The International Space Science Institute ISSI is proud to announce

Prof. Michael R. Meyer

(University of Michigan, USA) as the Johannes Geiss Fellow 2024.

Michael R. Meyer, Johannes Geiss Fellow 2024

Michael R. Meyer has been a Professor of Astronomy at the University of Michigan since 2016. He was Chair of Star and Planet Formation at the ETH in Zürich (2009-2016) and was formerly a Professor/Astronomer at the Department of Astronomy/Steward Observatory of the University of Arizona (2000-2009). He was a Hubble Fellow at the University of Arizona (1997-2000) and did a post-doc at the Max-Planck-Institute for Astronomie (1995-1997). Prof. Meyer is a world recognized expert in the formation, evolution, and characterisation of planetary systems, and associated implications on the prospects for life in the Universe. He has also been deeply involved in the development of ground- and space-based instrumentation, including both the NIRCam and NIRISS instruments for the James Webb Space Telescope as well as high contrast imaging systems/spectrographs for 6-10 meter telescopes and next generation extremely large telescopes. Prof. Meyer will visit ISSI in the summer of 2024.



The Fellowship is named after Prof. Johannes Geiss, the founder of the institute.


ISSI as an Observer of the Virtual Alpine Observatory (VAO)

The International Space Science Institute is now an associated partner in the research network of the Virtual Alpine Observatory (VAO). The VAO, located in Bavaria, Germany, is operating as a network of European High Altitude Research Stations based in the Alps and similar mountain ranges, and now includes ten countries (Austria, Bulgaria, Czech Republic, France, Germany, Georgia, Italy, Norway, Slovenia and Switzerland). In addition, the “International Space Science Institute (ISSI)” is welcomed as a new “observer”. ISSI now supports VAO in this capacity alongside the Alpine Convention and the European Space Agency (ESA). Find more information on the Webpage of the Virtual Alpine Observatory (VAO) >>

Michael Rast, ISSI Earth Science Director, and Michael Krautblattler, VAO Coordinator and Chair of the VAO Board 

“The Extraordinary First Year of Science of the James Webb Space Telescope” Pro ISSI Talk with Dr. Antonella Nota

The James Webb Space Telescope (JWST) is one of the most ambitious scientific mission ever flown, over 100 times more sensitive than its predecessor, the Hubble Space Telescope.

JWST has been designed to answer outstanding questions about the Universe and to make breakthrough discoveries in ALL fields of astronomy. Accessible to the scientific community worldwide, Webb is designed and built to offer scientists the capabilities needed to push the frontiers of knowledge of our own Solar System, of the formation of stars and planets, including planets outside our Solar System (exoplanets), and of galaxy assembly and evolution, in ways never before possible. 

Webb is observing the Universe in the near-infrared and mid-infrared. It carries a suite of state-of-the-art astronomical instruments capable of addressing a very broad spectrum of outstanding problems in astrophysics. The instrument complement includes powerful cameras, spectrographs, and coronagraphs, designed specifically to observe faint objects and structures in close proximity to very bright celestial targets.  The telescope was launched on December 25, 2021 on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, from where it embarked on a month-long journey to its final orbit about one and a half million kilometres from Earth, at what is called the second Lagrange point or L2. In the first three weeks after launch, Webb unfolded its five-layered sunshield, and deployed its  gold coated beryllium 6.5-metre primary mirror.  The launch and deployment were executed flawlessly and after a few months  of telescope and instrument verifications, the observatory was ready for science. The speaker will review these very first phases in the mission, the early excitement of realizing that, from the first data received, the observatory  performance was already exceeding the expectations of its designers and builders. One year later, JWST is producing a steady stream of breakthrough results in all field of astrophysics. The speaker will review the most significant recent  highlights and show how JWST is already changing the way we see the Universe.

Pro ISSI talk was recorded on November 1, 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

Job Posting: Scientific Communications Specialist

ISSI is seeking a skilled Scientific Communications Specialist who will be responsible for promoting ISSI’s brand, activities, and products to stakeholders in the international or national Swiss space science communities, at 30-40% level, available in January 2024.

Description of the position:

Create scientific content and messaging, related to ISSI scientific activities, to be disseminated via ISSI’s website, social media, and newsletters:

  • Generate biweekly scientific highlights from ISSI activities
  • Develop informational content for the ISSI website and social media
  • Generate highlights for special ISSI events (incl. e.g., Game Changer Seminars)
  • Create short interview/stories videos to be posted on the web
  • Liaise with the Pro ISSI association for education and outreach activities
  • Generate ISSI’s and J. Geiss fellowship (JGF) Wikipedia Webpage entries
  • Support the migration of the scientific content from the present website to the new one

Competences of the position:

  • Excellent knowledge of the English language, spoken and written (native English language is a plus)
  • Bachelor’s or Master’s degree related to Sciences, Linguistic, or Communications
  • Outstanding communications and networking skills in English and German
  • Proven track record of writing science-related media content, directed to an international audience
  • Interested in and experienced in working in an academic environment
  • Ability to work well in a small team as well as independently
  • Proficiency with MS tools such as Word, PPT, Excel, and other collaborative and communication tools
  • Experience with Photoshop, Illustrator, Adobe Pro are a plus

We offer:

  • Competitive remuneration, with conditions similar to the University of Bern
  • An exciting and welcoming international scientific enviroment

Deadline for Applications: November 30, 2023

Application Form >>


Global Change in Africa

Volume 86 in the Space Sciences Series of ISSI

The main objective of this book is to provide an overview of the benefit of using Earth Observation data to monitor global environmental changes due to natural phenomena and anthropogenic forcing factors over the African continent, and highlight a number of applications of high societal relevance. The main topics presented in the book concern: water resources, floods and droughts, coastal zones changes and exploitation of mineral resources and its impact on the environment. 

The chapters “Enhancing the Uptake of Earth Observation Products and Services in Africa Through a Multi-level Transdisciplinary Approach”, “Water Resources in Africa under Global Change: Monitoring Surface Waters from Space”, “Water Resources in Africa: The Role of Earth Observation Data and Hydrodynamic Modeling to Derive River Discharge”, “The Role of Space-Based Observations for Groundwater Resource Monitoring over Africa”, “Hydrometeorological Extreme Events in West Africa: Droughts”, “Hydrometeorological Extreme Events in Africa: The Role of Satellite Observations for Monitoring Pluvial and Fluvial Flood Risk”, “Artisanal Exploitation of Mineral Resources: Remote Sensing Observations of Environmental Consequences, Social and Ethical Aspects” and “Coastal Zone Changes in West Africa: Challenges and Opportunities for Satellite Earth Observations” are available open access under a Creative Commons Attribution 4.0 International License via

 This volume results from a remote Workshop organized by the International Space Science Institute (ISSI) on 11–15 January 2021.

The volume is edited by A. Cazenave, D. Baratoux, T. Lopez, J.K. Kouamé, J. Beneviste, and L. Moreira and all chapters are co-published open access in Surveys in Geophysics, Volume 44, Issue 1, 2023

Hard Copy >>



Probing Earth’s Deep Interior using Space Observations Synergistically

Volume 85 in the Space Sciences Series of ISSI

During the recent decades, space missions (e.g., CHAMP, GOCE, GRACE and Swarm) have been developed by space agencies in Europe and the USA to measure the Earth’s gravity and magnetic fields and their spatio-temporal variations. These successful missions have already provided a wealth of groundbreaking results about the permanent and time-variable gravity and magnetic fields of the Earth. However, more can be learned about the Earth’s structure by combining data of the gravity and magnetic fields, together with Earth’s rotation data routinely measured using space geodesy techniques, as well as with the most up-to-date modelling of the Earth’s internal structure. Use in synergy of these global observables and model data represents a unique way to further investigate the physics of the deep Earth’s interior. In addition to the well-known correlation between Earth’s rotation and magnetic field observed at interannual and decadal time scales, recent studies have reported unexpected correlation between spatio-temporal changes of the gravity field and magnetic field, also at interannual time scale. These changes may result from processes occurring in the liquid core and at the core-mantle boundary.

This book gathers a series of chapters that provide state-of-the art overviews on the gravity field, magnetic field and Earth’s rotation observations, and on their interpretation in terms of the deep Earth’s structure, as well as on core dynamics and processes at the core-mantle boundary. This volume results from a Workshop held at the International Space Science Institute (ISSI) in Bern on 1–4 September, 2020.

The chapters ‘Gravity Variations and Ground Deformations Resulting from Core Dynamics’, ‘Rapid Variations of Earth’s Core Magnetic Field’, ‘A Dynamical Prospective on Interannual Geomagnetic Field Changes’, ‘Core Eigenmodes and their Impact on the Earth’s Rotation’, ‘Earth’s Rotation: Observations and Relation to Deep Interior’, ‘Interiors of Earth-Like Planets and Satellites of the Solar System’, ‘Correction to: Interiors of Earth-like planets and satellites of the Solar System’, ‘Fluid Dynamics Experiments for Planetary Interiors’, ‘Structure, Materials and Processes in the Earth’s Core and Mantle’, ‘Correction to: Structure, Materials and Processes in the Earth’s Core and Mantle’ and ‘Applications and Challenges of GRACE and GRACE Follow-On Satellite Gravimetry’ are available open access under a Creative Commons Attribution 4.0 International License via 

The book is edited by Veronique Dehant, Mioara Mandea,  Anny Cazenave, Lorena Moreira and all chapters are co-published open access in Surveys in Geophysics, Volume 43, Issue 1, 2022

Hard Copy >>



Magnetic Switchbacks in the Young Solar Wind

Workshop Report Magnetic Switchbacks in the Young Solar Wind convened by Marco Velli, Maria Madjarska, Stuart Bale, Olga Panasenco, Etienne Pariat, Anna Tenerani, Tim Horbury, and Thierry Dudok de Wit

The observation by NASA’s Parker Solar Probe mission of very strong magnetic field fluctuations in the inner heliosphere, leading to strong deflections locally reversing the direction of the field itself, called switchbacks, has attracted considerable attention from the heliophysics and space physics communities.

Workshop Participants 

A recent ISSI workshop (18–22 September 2023) brought together solar and solar wind scientists with the objective of better understanding how these structures are formed and how they contribute to solar wind heating, acceleration, and the scattering of energetic particles. Though there remain competing theories for the formation and development of switchbacks, a major outcome of the workshop was the recognition of role played by small scale energetic magnetic field annihilation (or reconnection) events, exchanging plasma between open and closed fields in the lower corona, that lead to the development of small-scale jets of hot plasma. There is general agreement that these may provide the necessary conditions for the formation of switchbacks in the corona and inner heliosphere. A series of review papers describing the current state of our understanding of switchbacks and the outcomes of the workshop will be published in the journal Space Science Reviews and as a volume in the Space Science Series of ISSI.