Rapid advances are transforming the way in which we watch the atmosphere from space. Many Earth-observing satellite missions built to study land, water, and minerals turn out to be serendipitous sensors of anthropogenic gas emissions, capable of spotting individual sources of harmful gases that were previously invisible. For methane, a potent greenhouse gas, these methods have matured rapidly and now routinely pinpoint major leaks worldwide. Building on this success, the same instruments are being shown to also detect plumes of carbon dioxide, ammonia, nitrogen dioxide, ethylene, and carbon monoxide. This rapidly expanding capability opens an unprecedented window onto the world’s largest pollution sources. Upcoming missions, especially global-coverage imaging spectrometers such as ESA/Copernicus’ CHIME, promise to turn these detections into routine, operational monitoring.

Luis Guanter obtained his Ph.D. in Environmental Physics in 2007 from the Universitat de València (Spain). After several postdoctoral positions in Germany and UK, he became Head of the Remote Sensing Section of the GFZ Potsdam in Germany and the Principal Investigator of the satellite imaging spectroscopy mission in 2014. Since March 2019 he is a Full Professor in Applied Physics at the Universitat Politècnica de València (UPV) in Spain, where he is leading the LARS (Land and Atmosphere Remote Sensing) group in January 2020. His research is focused on the use of satellite-based spectrometers for the monitoring of the Earth’s surface and atmosphere. Luis Guanter has been included in Clarivate’s Highly Cited Researchers List of the world’s most influential scientists since 2019.

Meet Dr. Colleen Golja, atmospheric scientist working at the intersection of chemical engineering and climate research, visiting ISSI as part of a Working Group on stratospheric processes.

Listen to Colleen as she traces her path from an early fascination with chemical engineering and energy systems to a growing concern about climate change that pulled her toward atmospheric science. She explains why the stratosphere, and the ozone layer within it, matters so much.

Colleen walks us through the discovery of the ozone hole and one of the most successful international environmental agreements ever adopted. She describes her own work piecing together satellite measurements of ozone, water vapour, wind, and temperature, and highlights the value of her ISSI Working Group.

Beyond the science, Colleen reflects on returning to ISSI for a second time, this time in the warmth of a Bernese summer and closes with a note of hope.

The launch of Parker Solar Probe (Parker) in 2018, accompanied shortly after by the launch of Solar Orbiter (Orbiter), has opened a new frontier in the exploration of the Heliosphere. One of the first observations by Parker Solar Probe was that much of the solar wind, independently of speed, is dominated by Alfvénic fluctuations, suggesting that these fluctuations play a vital role in Heliospheric dynamics. Parker also observed that the Heliospheric current sheet is extremely dynamic in its formation region, with reconnection being a persistently observed process. It has been established since the early observations by Helios (and later confirmed by Ulysses and SOHO) that the sources of fast solar wind streams at solar minimum are polar coronal holes. In contrast, slower solar wind streams have contributions from different sources.

The larger than expected filling factor of slow solar wind has been attributed, in addition to flows surrounding the Heliospheric current sheet, to flows coming from coronal hole boundaries, i.e., regions with large expansion factors, or from regions where the mapping of the magnetic field from the photosphere into the heliosphere is complex, as identified for example by the squashing factor. This is known as the S-Web. The ubiquity of Alfvénic fluctuations in the inner Heliosphere, and the frequent observation of slow Alfvénic solar wind by Parker Solar Probe as well as Solar Orbiter, previously observed relatively rarely in Helios and Wind data, provide evidence for a picture of solar wind origins that incorporates both the expansion factor and S-web paradigms: both coronal holes with large expansion and S-Web regions act as slow sources of the solar wind, with the difference that highly expanding coronal holes provide Alfvénic slow streams, while the S-web wind is unlikely to exhibit strong Alfvénic correlations. Over the solar cycle the distribution of solar wind flows changes, and we will highlight how observations from Parker Solar Probe and Solar Orbiter have opened new perspectives on how the solar magnetic field is advected into the Heliosphere.

Marco Velli studied plasma physics at the University of Pisa and Scuola Normale Superiore under Profs. Bruno Coppi and Francesco Pegoraro. He subsequently held post-doctoral appointments at the University of St. Andrews and the Observatoire de Paris, Meudon, where he collaborated with A. Mangeney and R. Grappin on studies of the solar wind and its embedded turbulence. In Paris he developed the idea that reflection plays a fundamental role in driving turbulence in the solar wind, and followed that with the expanding box model allowing simulation studies of turbulence in the inhomogeneous solar wind. He was professor at the University of Firenze and Principal Scientist at the Jet Propulsion Laboratory, where as lead theorist he helped develop the Solar Probe concept presently flying as Parker Solar Probe. Since 2014 he has been Professor of Space Physics in the Earth, Planetary and Space Sciences Department at UCLA. For his research he was elected fellow of the AGU in 2014 and awarded the Parker lecture in 2022, and was Johannes Geiss fellow at ISSI in 2022.

Another year, another milestone! 💫

ISSI's 2025 Annual Report is here, and what a year it has been. From monitoring our changing Earth to exploring the deepest corners of the cosmos, ISSI continued to push the boundaries of space research across every domain: from Earth Science, to Planetary Science and Heliophysics, all the way to Astrophysics.

Discover all of this and more in our brand new digital Annual Report.

Video created by ISSI Communications Intern Mathieu Marié.

#ISSI #SpaceResearch #AnnualReport2025 #SpaceScience #Astrophysics #EarthObservation #SolarPhysics

About 44 times per second a lighting stroke hits out planet. As one of the most awe-inspiring phenomena in nature, we are all deeply familiar with the immediate consequences of lightning: thunder, the flash of light and possibly the destruction that it leaves in its wake. However, lightning is also associated with other consequences that you may miss in the blink of an eye: far above lightning, close to the boundary between our atmosphere and space, lightning produces strange luminous events with playful names such as sprites and elves. Discovered almost 40 years ago but predicted long before, these Transient Luminous Events (TLEs) teach us about the fundamental physics of electric discharges and about Earth’s upper atmosphere. In this webinar we will review how our understanding of TLEs has evolved since they were observed and what challenges they still offer for future research.

Alejandro Luque graduated from the University of Sevilla, his native town. He then obtained a PhD in theoretical Plasma Physics from the University of Bayreuth (Germany). He did a postdoc at the Ruhr-University in Bochum (Germany) and then at the Center for Mathematics and Computer Science (CWI) in Amsterdam, The Netherlands, where he became acquainted with the physics of electrical discharges. In 2010 he moved back to Spain and to the Institute for Astrophysics of Andalucía (IAA), part of the Spanish High Council for Research (CSIC). There he currently researches different aspects of atmospheric electricity in Earth and other planets of our Solar System.

Pro ISSI Talk: The Moon is our nearest neighbour, and the only other planetary body humans have ever set foot on. We have been exploring the Moon via manned and robotic missions for more than half a century, but there are still many parts of its history that we cannot explain. Given the relatively small size of the Moon, it is reasonable to assume it cooled down very quickly and has been geologically ‘dead’ for much of its history. However, a huge number of observations refute this assumption. Magnetic measurements on Apollo samples highlight that the Moon was able to generate its own magnetic field that was, for a time, even stronger than Earth’s magnetic field today. New chemical data from the Chinese Lunar Exploration Program suggests the Moon has had active volcanism, with lava flowing onto the surface for more than 3 billion years. In this talk, I will explore some newly revealed links between the volcanic and magnetic

Earth-set beyond the Moon captured through the Orion spacecraft window. Image credit: NASA, Christina Koch

The Hubble Space Telescope (HST) and James Webb Space Telescope (JWST) together offer an unprecedentedly detailed view of galaxies across cosmic time, from the first few hundred million years after the Big Bang through today. However, even these uniquely powerful telescopes struggle to resolve the small-scale building blocks of galaxies in the distant universe. Gravitational lensing provides an extra boost to the resolving power of HST and JWST, using massive galaxy clusters in the foreground as cosmic telescopes to magnify distant galaxies. In this talk, the speaker will discuss how the combination of HST, JWST, and gravitational lensing provides a window into the heart of distant galaxies, revealing compact star clusters and even individual massive stars that are key engines of evolution within galaxies. These measurements enable us to better understand how distant galaxies form stars, stop forming stars, and build up elements such as nitrogen, oxygen, and carbon that form the fundamental building blocks of life on Earth.

Brian Welch is an Astronomer and currently a Fellow at the International Space Science Institute. Brian holds a PhD from Johns Hopkins University (USA) , during which he explored the inner workings of distant galaxies, merging the power of the Hubble Space Telescope and gravitational lensing (when a very large celestial body bends the path of light around it, distorting and magnifying it, similar to what would happen with a lens). This was followed by post-doctoral work at NASA Goddard Space Flight Center, where he worked from 2022 until 2025. Since September 2025 he is a part of the ISSI Staff.

Meet Dr Sara Gasparini, space physicist and aurora researcher, and former visiting scientist at ISSI ahead of leading her own ISSI International Team. Listen to Sara as she traces her path from a childhood passion for the universe to an unexpected, and fortuitous, dive into the Northern lights during her PhD.

Sara explains how auroras are far more than a spectacular light show: they offer a window into the interaction between the Earth's magnetic field and the solar wind, and into the plasma processes shaping our near-Earth environment. She walks us through the multi-instrument toolkit she relies on, from ground-based magnetometers and SuperDARN radar networks to auroral imagers and satellite measurements, and describes her ISSI International Team's work combining these observations to achieve high temporal and spatial resolution of auroral mesoscale structures.

Beyond the science, Sara makes a compelling case for scientists with deep domain expertise to step up and communicate their work directly to the public, not just to peers, and reflects on the value of ISSI as a place to forge new collaborations across career stages.

Finally, Sara shares what keeps her grounded outside the lab and reveals her strong opinions on the ideal pastry to accompany a starry Arctic night.

Meet Dr Franck Ghomsi, researcher at the National Institute of Cartography in Cameroon, associated with the Nansen-Tutu Center in South Africa, and currently a visiting scientist at the University of Manitoba (CEOS). Listen to Franck as he shares how a childhood fascination with the Moon's pull on the oceans set him on a path from Cameroon through Europe to the Americas — always driven by a passion for capacity building in Earth science.

Franck explains how Africa is already experiencing sea level rise above the global mean, and why understanding the contribution of Antarctic meltwater to coastal dynamics is critical for low-GDP communities living at the shoreline.

Beyond the science, Franck makes a compelling case for open-access tools and data as the great equaliser in global research, and reflects on the barriers still facing scientists from the Global South: from software access to publishing paywalls to underrepresentation in international panels. He calls for a more inclusive science that listens as much as it speaks.

Finally, Franck shares his warm first impressions of ISSI and Bern.

Now that some records stretch back over four decades, observations of Earth from space are used widely in climate science. Observation-based trends in a range of essential climate variables are important as direct indicators of tendencies that may persist in coming decades, and to assess climate-model based projections. Requirements for the stability (the trend fidelity) of observations of essential climate variables have been internationally coordinated through the Global Climate Observing System (GCOS). The fidelity of the observed trends is important to consider – not least because we often must exploit early missions that were not originally specified for climate monitoring. Despite this, climate data records are often analysed as if the observations are perfectly stable. This webinar will explore why that is, why that needs to change, and what would constitute better practice both in specifying stability requirements and in quantifying trend uncertainties. Along the way, we will encounter some of the important climatic trends that are shaping our climate future.

Christopher Merchant is Professor of Ocean and Earth Observation at the University of Reading, and part of the National Centre for Earth Observation in the UK. He has been involved in the quantification and understanding of climate change from Earth observations for many years, since completing a related doctorate at University College London. He has worked extensively with the European Space Agency, in the (former) Earth Science Advisory Committee and still within the Climate Change Initiative. He led a major project, FIDUCEO, focussed on innovations to bring metrological rigour to Earth observations. His team at Reading have developed capabilities in quantitative thermal remote sensing that have enabled climate data records for surface temperature to be obtained from 40 years of satellite observations.