Publications

Surface-Bounded Exospheres and Interactions in the Inner Solar System

Spotlight Publications

New Topical Collection published in Space Science Reviews (Open Access)

A new collection of 8 review articles has been completed and is available online in Space Science Reviews, a printed book version will be published as volume 84 of the Space Sciences Series of ISSI.

Studying the evolution of the surfaces and atmospheres of planetary bodies in the solar system is fundamental to our understanding of the present state of the solar system. Exospheres are the interfaces between the planetary body and the open space, so that, studying the exospheric filling and loss processes is the way to expand knowledge of the body’s evolution. While the exospheres are present around any kind of planetary body, they are quite different if we consider the bodies with an atmosphere and those without a collisional gas envelope.  In the latter case the exosphere is directly connected to the surface, thus, it is called surface-bounded exosphere, since the surface release processes are also the exospheric filling ones and atoms and molecules collide with the surface far more frequently than collisions with each other. 

Edited by Anna Milillo, Menelaos Sarantos, Benjamin D. Teolis, Go Murakami, and Peter Wurz, this collection presents results from the ISSI Workhop “Surface Bounded Exospheres and Interactions in the Solar System”, held 20–24 January 2020, which reviewed the knowledge on the surface-bounded exosphere conditions, generation, variability and loss processes, from theoretical, observational and experimental points of view. The output collects the present state of knowledge on this subject and drafts a roadmap for future investigations in view of the next missions, i.e., BepiColombo to Mercury or orbiters and landers to be operated on the Moon.

Complete Topical Collection in Space Science Reviews >>

Human-Caused Warming and Naturally Occurring Cycles Together Regulate Extreme Ocean Events

Spotlight Johannes Geiss Fellowship, Publications, Science

Global sea level and extreme ocean events are rising due to human-caused climate change. The amount of rise in sea level and number of increase in extreme events, however, vary greatly from region to region and they also change over time. To fully understand these changes and thus build the capability of predicting when and where they may occur in the future, we must also consider naturally occurring climate variability. By combining in situ and satellite observations with model simulations, Weiqing Han and collaborators recently investigated the sea level Height EXtreme (HEX) events and co-occurring Marine heatwaves, dubbed Compound Height-Heat EXtreme (CHHEX) events, along Indonesian coasts of the Indian Ocean since the 1960s, particular since 1993 when satellite altimetry data have become available. They found out that most of the HEX and CHHEX events occured during the period from 2010 to 2017. Sea level rise due to the anthropogenic warming and naturally occurring decadal climate variability combined to boost up the HEXs from 2010 to 2017. While the individual HEX-alone events are mainly driven by enhanced northwesterly winds associated with the Indian and/or Australian monsoons from December to March, CHHEXs occur in May-June and November-December mainly in years when negative Indian Ocean Dipole (IOD) and La Niña, the negative phase of the El Niño – Southern Oscillation (ENSO), co-occur. The ENSO and IOD are the dominant natural internal climate variability patterns at interannual time scale. When they co-occur, the intensified equatorial westerly winds and longshore northwesterly winds drive the HEX and CHHEX events. A recent study – published in Nature Communications in October 2022 – suggests the importance of the interplay between interannual-to-decadal climate variability and anthropogenic warming in shaping the extremes, which may help improve decadal predictions and near-term projections of the high impact extreme events. For further details, see the University of Colorado Boulder news release.

Figure: Linear trend maps of satellite observed sea level and surface wind stress from 1993-2018 (left figure).  Time series of monthly-mean sea level anomalies from tide gauge observation (black curve) at Java coast (location marked “x2” in the left panel), from satellite observation at the nearest grid point (red), and from the European Centre for Medium-Range Weather Forecasts (ECMWF) Ocean Reanalysis System 4 (ORAS4) ocean reanalysis data at the nearest location (blue)(right figure). (Credit: W. Han)

 

 

Weiqing Han

Prof. Weiqing Han (University of Colorado at Boulder, USA) is elected Fellow of American Meteorological Society in 2023 and was selected as the Johannes Geiss Fellow in 2020. Because of the Covid-related travel restrictions, Weiqing Han visited ISSI for the first time in summer 2023. Weiqing has been working on a number of research topics, including understanding the remote versus local forcing in driving year-to-year variations of the U.S. east coasts sea level, exploring the roles of atmospheric intraseasonal oscillations – particularly the Madden-Julian Oscillation – in causing sea level extremes along the Indonesian coasts, finding new climate patterns in the tropical Atlantic and Indian Oceans, and investigating the Indian-Pacific-monsoon interactions as well as the global linkage of decadal sea level patterns.

edited by Andrea Fischer

The Heliosphere in the Local Interstellar Medium: Into the Unknown

Spotlight Publications

New Topical Collection published in Space Science Reviews (all papers are Open Access)

A new collection of 18 review articles has been completed and is available online in Space Science Reviews, a printed book version will be published as volume 88 of the Space Sciences Series of ISSI.

This collection presents results from the ISSI Workhop “The Heliosphere in the Local Interstellar Medium”, held 8–12 November 2021, which aims to describe the complete heliosphere, including the heliopause and the effects of the heliosphere on the LISM. It covers observations and modelling and highlight what has been learned and what is still not understand. Although emphasis is on the results of the past decade, the full interaction from pickup ions to the termination shock to the LISM is covered with the goal of making this a complete reference.

This Topical Collection is edited by John D. Richardson, Andrei Bykov, Frederic Effenberger, Klaus Scherer, Rudolf von Steiger, Veerle J. Sterken, and Gary P. Zank.

Introduction: Richardson, J.D., Bykov, A., Effenberger, F. et al. The Heliosphere in the Local Interstellar Medium: Into the Unknown. Space Sci Rev 219, 6 (2023). https://doi.org/10.1007/s11214-023-00957-z

Complete Topical Collection in Space Science Reviews >>

 

Global Change in Africa

Spotlight Publications

New special issue in Surveys in Geophysics (partial Open Access) >>

The contribution of Africa to global greenhouse gas emissions is among the least important, yet Africa’s “key development sectors have already experienced widespread losses and damages attributable to anthropogenic climate change, including biodiversity loss, water shortages, reduced food production, loss of lives and reduced economic growth” (IPCC, 2022). Consequently, a prioritized task for Africa is to improve climate resilience in order to achieve sustainable and equitable development and to guarantee the quality of life for its population. In that context, in January 2021 the International Space Science Institute (ISSI, Bern) organized a workshop on “Global Change in Africa”. The main objective of the workshop was to investigate the benefits of using Earth Observation (EO) data to monitor global environmental changes due to natural phenomena and anthropogenic forcing factors over the African continent and to highlight a number of applications of high societal relevance. Another objective was to discuss the opportunities for collaborations between the international transdisciplinary scientific community and local research institutes as well as with African national and intergovernmental agencies. The workshop, in hybrid form due to the COVID-19 epidemic, gathered 31 participants from 11 different countries, including 6 participants from Africa.

This special issue will be reprinted as as the Volume 86 in the Space Science Series of ISSI and is edited by Anny Cazenave, David Baratoux, Teodolina Lopez, Jean Kan Kouamé, Jérôme Benveniste and Lorena Moreira.

 

Oscillatory Processes in Solar and Stellar Coronae

Spotlight Publications, SSSI Volumes

Volume 76 in the Space Science Series of ISSI 

The volume presents a broad and in-depth overview of recent achievements and the current state of research in magnetohydrodynamic (MHD) oscillatory and wave phenomena in the coronae of the Sun and stars. Major progress in coronal wave studies has been achieved thanks to the combination of high-precision multi-wavelength observations with spaceborne and ground-based facilities, elaborated theory of the interaction of MHD waves with plasma non-uniformities, state-of-the-art numerical simulations, and novel data analysis techniques. It has allowed the research community to reach a new look at the role played by MHD wave processes in the enigmatic phenomena of coronal plasma heating and wind acceleration as well as powerful energy releases such as flares and coronal mass ejections. In addition, the waves are intensively used as natural probes in the remote diagnostics of the coronal plasma parameters and physical processes operating in solar and stellar coronae via the method of MHD seismology. Individual chapters cover recent cutting-edge results obtained on the analysis and theoretical modelling of several most intensively studied coronal MHD wave phenomena, namely, kink and sausage oscillations of coronal loops and other field-aligned plasma structures, plus running and standing slow magnetoacoustic waves. A dedicated chapter assesses the reliability of proposed theoretical mechanisms for heating of the coronal plasma by MHD waves. Another chapter summarizes the current state of our understanding of the physical mechanisms and observational properties of quasi-periodic pulsations in solar flares, considers their analogy with similar processes detected in stellar flares, and thus establishes solid ground for the further exploitation of the solar-stellar analogy. An important discussion of novel data analysis techniques designed recently for MHD seismology applications is presented in a devoted chapter. The direction of future advances in the designated research areas are discussed.

This volume presents results from a workshop held at the International Space Science Institute in Beijing (ISSI-BJ) on 14–19 October 2019.

This volume is edited by V.M. Nakariakov, D. Banerjee, B. Li, T. Wang, I. Zimovets, M. Falanga and co-published as Topical Collection in Space Science Reviews (partial Open Access) >>
 

Probing Earth’s Deep Interior using Space Observations Synergistically

Spotlight Publications, Workshop

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.

Oscillatory Processes in Solar and Stellar Coronae

Spotlight Publications

New Topical Collection published in Space Science Reviews (partial open access)

In 2019, the solar physics research community celebrated the 50th anniversary of the first detection of oscillatory processes in the solar corona as a quasi-periodic pulsation (QPP) of an X-ray and radio emission produced by a solar flare.

The International Space Science Institute in Beijing (ISSI-BJ) hosted the Workshop “Oscillatory Processes in Solar and Stellar Coronae” on 14–19 October 2019. This event was attended by more than forty specialists from more than ten countries. Outcomes of the workshop resulted in this Topical Collection which consists of seven comprehensive review papers. The reviews cover cutting-edge recent results obtained on the analysis and theoretical modelling of several most intensively studied coronal MHD wave phenomena, namely, kink and sausage oscillations, and running and standing slow waves. A dedicated review assesses the consistency of proposed theoretical mechanisms for heating of the coronal plasma by various MHD waves. Another review summarises the current state of the physical mechanisms and observational properties of QPPs in solar flares and considers their analogy with QPPs in stellar flares. An important discussion of novel data analysis techniques designed recently for MHD seismology applications is subject to a special paper. 

This Topical Collection will be reprinted as the Volume 76 in the Space Science Series of ISSI and is edited by Valery M. Nakariakov, Dipankar Banerjee, Bo Li, Tongjiang Wang, Ivan Zimovets and Maurizio Falanga.

Complete Topical Collection: “Oscillatory Processes in Solar and Stellar Coronae”, edited by Valery M. Nakariakov, Dipankar Banerjee, Bo Li, Tongjiang Wang, Ivan Zimovets and Maurizio Falanga

Introductory Article: Nakariakov, V.M., Banerjee, D., Li, B. et al. Editorial to the Topical Collection: Oscillatory Processes in Solar and Stellar Coronae. Space Sci Rev 218, 13 (2022). https://doi.org/10.1007/s11214-022-00888-1

The Tidal Disruption of Stars by Massive Black Holes

Spotlight Publications, SSSI Volumes

Volume 79 in the Space Sciences Series of ISSI

This volume provides an overview of the fast-developing field of tidal disruption events.

For several decades, astronomers have speculated that a hapless star could wander too close to a super massive black hole (SMBH) and be torn apart by tidal forces. It is only with the recent advent of numerous wide-field transient surveys that such events have been detected in the form of giant-amplitude, luminous flares of electromagnetic radiation from the centers of otherwise quiescent galaxies. These discoveries span the entire electromagnetic spectrum, from γ-rays through X-rays, ultra-violet, optical, infrared, and radio. A small number of events launch relativistic jets. These tidal disruption events (TDEs) have caused widespread excitement as they can be used to study the properties of quiescent, otherwise undetectable, SMBHs; the populations and dynamics of stars in galactic nuclei; the physics of black hole accretion including the potential to detect relativistic effects near the SMBH; and the physics of (radio) jet formation and evolution in a pristine environment. For scientific questions concerning quiescent SMBHs, TDEs are unique probes beyond the local universe. TDEs can also occur around active galactic nuclei (AGNs), although uniquely identifying such an event on top of a bright AGN is difficult.

Currently, the diverse emission properties of flares associated with TDEs is not fully understood. This challenge is being addressed by a sharp increase in observational work and theoretical modelling. Over the next few years, the largest growth areas will likely be in the greatly expanded surveys of the transient sky, and in new numerical modeling techniques. Together these will reveal how SMBHs shine by ripping apart orbiting stars and swallowing the stellar debris.

In light of this foreseen growth, many new researchers are expected to enter the field. Therefore, the time was deemed ripe to compose a comprehensive overview of the state of the art in this rapidly-evolving field. This volume results from a Workshop held at the International Space Science Institute (ISSI) in Bern on 8–12 October, 2018.

The book is edited by Peter G. Jonker, Iair Arcavi, E. Sterl Phinney, Elena M. Rossi, Nicholas C. Stone and Sjoert van Velzen

This Volume is co-published as Topical Collection in Space Science Reviews (partial Open Access) >>

Hard Cover Book >>

Geohazards and Risks Studied from Earth Observations

Spotlight Publications, SSSI Volumes

Volume 82 in the Space Sciences Series of ISSI

The Sentinel missions of the COPERNICUS Programme of the European Union, as well as other Earth Observation missions, provide new opportunities for systematic monitoring of natural and man-made hazards and disasters that can highly impact human societies.
The contributions collected in this book address a broad range of geohazards observable from space, including earthquakes, volcanic hazards, extreme events (e.g. storm surges, floods and droughts), fires, pollution, tipping points in physical and biological systems, etc. They provide information on how space observations can improve our understanding of the driving mechanisms at the origin of such geohazards, and of their mutual interactions. Focus is given on the expected added-value information obtained by combining different types of space-based and in situ observations as well as model results.

This volume results from the ISSI Workshop “Natural and Man-Made Hazards Monitoring by the Earth Observation Missions: Current Status and Scientific Gaps” held from 15 to 18 April 2019.

This volume is edited by T. Lopez, A. Cazenave, M. Mandea, J. Benveniste 

This volume is co-published in Surveys in Geophysics, 41, 6, November 2020 (partial Open Access) >>

Hard Cover Book >>

Auroral Physics

Spotlight Publications, SSSI Volumes

Volume 78 in the Space Sciences Series of ISSI

This volume surveys our current scientific understanding of the terrestrial aurora. It is organized into eleven reviews detailing theoretical and observational aspects of characteristic auroral morphologies, and how these in turn are organized according to local time, latitude, and activity level. 

Popular descriptions often attribute the aurora to the interaction of charged particles from the solar wind with atoms in the upper atmosphere. In fact, most auroras are not the result of direct entry of solar wind particles. Rather, as detailed in this volume, auroral particle acceleration and generation of auroral forms occur primarily within the magnetosphere. Importantly, many key aspects of the aurora – most notably, the physical mechanisms responsible for the generation of discrete arcs – are still unexplained, and auroral physics continues to be an active area of scientific research. Each review chapter therefore includes a summary of open questions for further investigation. 

This volume results from the ISSI Workshop Auroral Physics held from 6 to 10 August 2018.

This volume is edited by D.J. Knudsen, J.E. Borovsky, T. Karlsson, R. Kataoka, N. Partamies

This volume is co-published in Space Science Reviews in the Topical Collection “Auroral Physics” (Partial Open Access) >>

Hard Cover Book >>