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.

The Economics and Law of Space-Based Commerce (WTI-ISSI Conference 17–19 January 2024)

This workshop will focus on the economics and governance of commercialisation in outer space. It will look at the applicability of economic concepts, the concepts of international economic law, and the concepts of economic governance to space-based commerce.

The goal of the workshop is twofold. The first goal is identifying promising areas for future research along the lines outlined above, specifically a cross-disciplinary mix of economics, law, political science, and applied natural science. The second goal is to enlist interested researchers in setting up a research and workshop agenda and loose organizational/coordinating structure (a researcher network) based on the areas identified.

The workshop will be hosted jointly by the World Trade Institute (WTI) and the International Space Science Institute.

Venue: ISSI, Hallerstrasse 6, CH-3012 Bern (first floor)

Call for Papers

Submission Guidelines: Please submit paper proposals on original and unpublished research related to this call for papers. Abstract submissions must be between 300-500 words in length and should be accompanied by a short CV.

To submit your proposals, for further details, or to express interest, please contact Sophia Thompson,

Deadline for abstracts: 15 September 2023.

Accepted authors will be notified by 15 October 2023.

Further information >>

Climate Tipping Points: Earth Observations to Address a Key Climate Uncertainty

Workshop Report Tipping Points and Understanding EO data needs for a Tipping Element Model Intercomparison Project (TipMIP) by Annett Bartsch, Hannah Liddy, Mike Rast, Narelle van der Wel, Richard Wood, Sophie Hebden, Tim Lenton, Victor Brovkin

It’s fair to say that climate tipping points — defined by the Intergovernmental Panel on Climate Change (IPCC) as critical thresholds in a system that, when exceeded, can lead to a significant change in the state of the system — are by now a familiar concept, often used to convey the urgency of addressing climate change. World leaders at the COP27 climate conference of the UNFCCC in Sharm el-Sheik in November 2023 agreed on the need to understand the impact of tipping points on the cryosphere. 

The growing popularity of this concept for motivating climate action also underscores the need for the scientific community to better understand the risks posed by self-reinforcing and difficult-to reverse processes taking place in the climate system. We need to understand the impacts that tipping points will have at different levels of global warming in order to guide mitigation and adaptation efforts. 

The risks gaining particular attention include shifts in the Amazon from rainforest to savannah, a slowing- and potential shutting down of the Atlantic Meridional Overturning Circulation (AMOC), ice loss from the Greenland and Antarctic ice sheets as well as growing CO2 and CH4 emissions from thawing permafrost. Our best global climate models don’t yet include all potential climate tipping processes. This limits the scientific information available to guide policies to manage the risks to social systems, and we are still a long way from implementing an observing system that can monitor the onset of tipping points. 

Future Earth has been working closely with the World Climate Research Program (WCRP) through the Earth Commission and the AIMES global research network to build the research agenda in this area, hosting a series of webinars focused on different climate tipping elements. One key research activity is to improve climate model representation of tipping elements through a model intercomparison exercise. From the observations side, researchers came together with climate modelers at a Workshop hosted at the International Space Science Institute in Bern, Switzerland in October 2022, supported by the European Space Agency (ESA)-Future Earth joint program.

ISSI Workshop Participants

Animated discussions covered how Earth Observation (EO) together with modeling efforts can support monitoring and process understanding of tipping points and their interactions, climate feedbacks, and abrupt climate change more broadly. The EO and modeling communities have operated somewhat in silos. This workshop illustrated how important it is to get scientists from both communities into one room to understand one another’s challenges and priorities. This is what was achieved in the ISSI Bern Workshop, and it highlighted how exciting it is to examine research questions from observational, modeling and theoretical perspectives.

What is TIPMIP?

Coordinated coupled-model intercomparison projects are a useful approach to assess our understanding of climate processes by providing a standard set of experiments and initialization data that can be run by individual climate modeling centers around the world. The differences in the model outputs create an ensemble of simulated climate behavior that can be used to explore the robustness or uncertainty – both spatially and temporally – of the processes involved.

The ‘TIPMIP’ – TIPping element Model Intercomparison Project initiative, led by Earth Commissioner Ricarda Winkelmann, who is based at the Potsdam Institute for Climate Impact Research, will outline a set of experiments to explore the sensitivity of tipping behavior in response to rising levels of carbon dioxide in the atmosphere.

There is not a strong quantitative understanding within the climate research community about the drivers or processes involved in triggering climate tipping points, since they often fall into the category of ‘High Impact, but Low Likelihood’ events, and so are seen fairly infrequently in model results. Therefore, the first phase of TIPMIP experiments will take a highly idealized approach that can be easily run by a range of models.

It will begin with a set of experiments that provide a strong forcing of the climate system, with an increase in atmospheric CO2 of 1% per year. In addition, three more experiments will be defined to assess the impacts associated with specific levels of CO2. These experiments will lay the groundwork for understanding climate tipping behaviour and how societal activity can both drive and be impacted by abrupt change.

Earth Observations for Direct Monitoring of Tipping Behavior

The limited temporal extent of the satellite record – spanning 4-5 decades at best – means that direct monitoring of trends and indicators for the onset of tipping points is restricted to ‘fast’ tipping points that occur over decades, that would apply to winter sea ice in the Arctic, the subpolar gyre, the Sahel/Monsoon system, forest dieback – both tropical and boreal, freshwater ecosystems, and Arctic permafrost. The workshop heard of the potential to develop proxy indicators of tipping behavior and instabilities, for example to indicate the triggering of collapse of the Antarctic Ice Sheet.

A major strength of EO is the ability to capture multiple temporal and spatial scales of tipping behavior, from local to regional to global, and from daily to interannual. Across these scales, there is potential for studying feedbacks in the Earth system that can lead to tipping points. There is opportunity to exploit satellite observations of the timing of events, to study extreme events and their impacts – including impacts on society, as well as cascading impacts and pace of change. The workshop identified the value of indicators with multiple variables that combine information from different sources to build a fuller picture of the processes occurring; for example to study the pressures affecting vegetation. It also called for better integration of EO data and platforms to facilitate the detection of tipping events.

Earth Observation for Modeling

EO has a key role to play in improving the ability of climate models to project possible climate futures. Climate models rely on long-term EO datasets like the Essential Climate Variables (ECVs), many of which are based on remote sensing data. ECVs developed by programs like the ESA Climate Change Initiative are used for model development, to assess model skill, (judged by how well models can reproduce past observations) and to constrain models – helping to determine certain parameters, for example, and to set initial conditions of part of the climate system at the start of a model simulation. The Global Climate Observing System (GCOS) is an international scientific body that maintains the definitions of the ECVs required for systematic observations of the Earth’s climate. The goal is to help solve research challenges like climate tipping points, and to underpin climate services and adaptation measures.  

Applied to tipping points, there is huge scope to ‘assimilate’ — a statistical approach that brings the model’s outputs closer to the observational data — EO to improve process-based models. For example, ocean color and sea surface temperature data could be used to better constrain biogeochemical or ecosystem processes in ocean ecosystem models to lower the uncertainty of predictions of thresholds and timescales of regime shifts. 

Research Frontiers

Recent wildfire and flooding events have highlighted society’s fragility in the face of worsening climate extremes. Society also faces compound climate extremes whereby multiple hazards occur in the same location, or concurrent extremes occur at different locations. An open question is how extreme events might interplay with tipping points to drive worse impacts on society. Research frontiers will push our current EO datasets and modeling tools into new territory, in combinations that enable an exploration of the interactions between tipping points in the climate and society. 

Through this workshop and other coordinated efforts by Future Earth and WCRP, there will be more opportunities to engage with the tipping point research community and TIPMIP initiative. Recordings of past webinars and information about those upcoming can be accessed here. Moreover, scientific sessions and meetings at EGU in April 2023 will be another opportunity for building bridges across scientific communities to enable us to better characterize the interfaces and identify and constrain the risks posed by tipping points.

This report was orginally published on




Workshop on Satellite-Based Analyses of Changes in Water and Energy Cycle (26–30 September 2022)

Unknown to many, Space and Earth scientists worldwide dedicate substantial efforts to monitoring the Earth’s climate in order to track changes to our planet, to understand changes to extremes, and the dangers of climate change.

Last week, the International Space Science Institute (ISSI) in Bern hosted a Workshop with scientists from Europe, North America and Japan to assess the current state of knowledge with respect to the monitoring of water cycle changes from satellites. Remy Roca, director of research with the French CNRS and one of the Workshop conveners, explains, “A vivid, truly international, scientific community is fully at work to build and sustain the needed space borne satellites for consolidating the scientific rationale underpinning climate change.“ Sonia Seneviratne, Professor at ETH Zurich and coordinating lead author in the last assessment report of the Intergovernmental Panel on Climate Change (IPCC), further emphasizes, “Satellite data products are an essential support to monitor the water cycle changes induced by greenhouse gas emissions.“

The global water and energy budget of the Earth of the early 21st century. Units Wm-2. The number in parenthesis are the uncertainty in the flux estimate. Also in Wm-2. (Figure Credit: Stephens et al., 2022, in revision with BAMS)

Monitoring the Earth’s water cycle is essential for understanding and predicting extreme changes that are occurring, as was illustrated by the extreme drought that affected Europe this summer and the recent devastating floods in Pakistan. “Viewing Earth from space allows us to see how Earth behaves as a whole and sustaining measurements of water and energy, done jointly, is essential for understanding how Earth’s fresh water is changing,” says Graeme Stephens, Director of the Center for Climate Sciences at JPL and principal investigator of the NASA CloudSat Mission.

Topics addressed during the Workshop include: estimates of the water and energy fluxes on Earth, global-scale changes in droughts and heavy precipitation, changes in the Earth energy imbalance and ocean heat storage, and changes in the surface temperature in response to the changing water energy fluxes.

Participants of the Workshop

The participants discussed ways to constrain climate model projections to better prepare for increasing climate change-related dire impacts. “Satellites are instrumental tools to observe the current changes in the water and energy fluxes on Earth and thus are at the core of our effort to improve our understanding of climate change,” says Benoit Meyssignac, researcher at the French space agency CNES and lead author of the IPCC special report on ocean and cryosphere.

The Workshop showed that the science community is now providing consistent satellite estimates of the global water and energy fluxes of planet Earth from the surface of the ocean to the top of the atmosphere over the last two decades. This observational basis serves as a reference to better understand the subtle balances at stake among the Earth’s water and energy fluxes in the current climate. The challenge of the next decade for scientists will be to detect, monitor and understand how climate change modifies these balances and the consequences for society. “Only with a sound and quantitative understanding of the energy and water fluxes on Earth will we be able to support decision makers on how to best protect the climate and environment of our planet,“ says Michael Rast, Director Earth Sciences at ISSI. “The giant hurricane which hit the Southern US last week and had millions watching meteorological satellite images loops, once again served to illustrate what is at stake and the Earth Observing community are taking action to ensure a safe future for our planet.”

Workshop Webpage >>

Probing Earth’s Deep Interior using Space Observations Synergistically

New special issue in Surveys in Geophysics (all papers open access)

During the last two decades, the GRACE and SWARM space missions have provided a wealth of groundbreaking results about the spatio-temporally variable gravity and geomagnetic fields of the Earth. However, more can be learned about the deep Earth’s structure by combining data of the Earth’s gravity and magnetic fields together with Earth’s rotation data routinely measured using space geodesy techniques, such as Very Long Baseline Interferometry (VLBI). The synergistic use of these three observables represents a unique way to investigate the physics of the deep Earth’s interior. In addition to the well-known correlation between the Earth’s rotation and magnetic field observed at the decadal time scale, recent studies have reported an unexpected correlation between spatio-temporal changes of the gravity field and of the magnetic field, also at the decadal time scale. Processes occurring in the liquid core and at the core–mantle boundary (CMB) are potentially responsible for this observation. The Workshop “Probing the Deep Earth Interior by using in synergy observations of the Earth’s gravity and magnetic fields, and of the Earth’s rotation” held at the International Space Science Institute (ISSI, Bern) on 1–4 September 2020, gathered about 40 scientists from different horizons and expertise to discuss this novel research topic. The different sessions successively addressed the capability of the gravity and magnetic fields, and Earth rotation observations to detect deep Earth signals on interannual time scales, the current knowledge of processes occurring in the fluid outer core, at the CMB and within the lower mantle, as well as the present-day status of theoretical models describing the deep Earth structure.

This Special Issue gathers together overview articles that provide state-of-the-art knowledge on the various aspects of this emergent research area. It addresses different timescales associated with these deep Earth observed signals as well as associated modeling aspects.

This special issue will be reprinted as as the Volume 85 in the Space Science Series of ISSI and is edited by Veronique Dehant, Mioara Mandea, Anny Cazenave and Lorena Moreira.