The Quest for Ancient Space Weather Reports

The great auroral display seen in Augsburg on 6 March 1582, reproduced in Usoskin et al. (2023) with permission from Zentralbibliothek Zürich, Department of Prints and Drawings/Photo Archive (shelfmark: ZB Graphische Sammlung (GSB), PAS II 19/4).
The great auroral display seen in Augsburg on 6 March 1582, reproduced in Usoskin et al. (2023) with permission from Zentralbibliothek Zürich, Department of Prints and Drawings/Photo Archive (shelfmark: ZB Graphische Sammlung (GSB), PAS II 19/4).
Earliest Records of Solar Events

The Sun often produces eruptive events on different energetic and temporal scales. It might, however, also produce events, so-called extreme solar events, whose energy could be orders of magnitude greater than anything we have observed during recent decades. But what is an extreme solar event? How strong can they be and how often do they occur?

To find answers to these and other questions, the ISSI team around Fusa Miyake from Nagoya University in Japan and Ilya Usoskin from Oulu University in Finland went back, far back in time.

Using a combined approach with so far unused measured and archival data, the team studies extreme space weather events that would have catastrophic impact not only on our astronauts and their equipment, but also on our power and communications infrastructure here on the ground.

The examined historical records date back over three millennia! One significant finding is the earliest documented reports of candidate aurorae known today, with a Babylonian astronomer reporting a “red glow” in 567 BCE and possible auroral sightings in Assyrian cuneiform tablets from 679–655 BCE. Additionally, the Bamboo Annals, an ancient Chinese text, describe a celestial event involving a “five-coloured light” in the last year of King Zhāo of the Zhōu Dynasty.

These reports have been correlated with modern records and analysed to determine their likelihood as auroral events, providing insight into ancient space weather occurrences. This research not only extends our space weather chronology but also suggests the existence of a solar minimum around 810–720 BCE, termed the “Neo-Assyrian Grand Minimum“, challenging previous understandings of solar activity during that period.

Read more about this fascinating undertaking in: Usoskin, I., Miyake, F., Baroni, M. et al. Extreme Solar Events: Setting up a Paradigm. Space Sci Rev 219, 73 (2023). https://doi.org/10.1007/s11214-023-01018-1

Exploring Climate Dynamics

Prof. Weiqing Han (University of Colorado at Boulder, USA) was selected as the Johannes Geiss Fellow in 2020. Background graphic from https://s-ink.org/sea-surface-temperature-2023-july
Prof. Weiqing Han (University of Colorado at Boulder, USA) was selected as the Johannes Geiss Fellow in 2020. Background graphic from https://s-ink.org/sea-surface-temperature-2023-july.

Insights from Professor Weiqing Han’s Research

The Earth’s atmosphere and ocean are in the focus of Professor Weiqing Han, who is affiliated with the University of Colorado and a former ‘Johannes Geiss Fellow’ at ISSI Bern. Her focus is predominantly on the dynamics of our evolving climate across intra-seasonal to decadal time frames. Important facets of her work encompass ocean dynamics, regional sea-level fluctuations, climate variability, and the intricate interplay between the atmosphere and the ocean. Below, Professor Han provides a synopsis of her latest publications arising from her time as an ISSI fellow.

Emergence of the central Atlantic Niño

The Atlantic Niño, a climate phenomenon characterised by regional sea surface warming in the equatorial Atlantic Ocean, has a significant impact on tropical climate, including the El Niño and Southern Oscillation (ENSO), which has large climatic impact worldwide. Our recent publication (Zhang et al. 2023) shows that the Atlantic Niño has undergone significant changes, with the emergence of two distinct types: the central and eastern Atlantic Niño. The eastern Atlantic Niño has been weakening since the 1970s, which allows the central Atlantic Niño to emerge and become more prominent since the early 2000s. In this study, we demonstrate that the central Atlantic Niño, with its unique spatial pattern, exerts a stronger influence on tropical climate compared to its eastern counterpart. This finding explains why we still see a strong remote impact on ENSO despite the weakening of both eastern and central Atlantic Niño combined. Differentiating between the two types of Atlantic Niño seems key for a comprehensive understanding of their climatic impacts on both local and remote regions, including their role in influencing ENSO.

Increase in MJO predictability under global warming

The Madden–Julian Oscillation (MJO) is an eastward-moving atmospheric disturbance that occurs in every 30-60 days in the tropics, with strong manifestations in clouds, rainfall, winds, and pressure. The MJO has significant impacts on global weather and climate and is a dominant source of their sub-seasonal predictability. Our recent study (Du et al. 2023) found that the MJO has become more predictable (i.e., increase in predictability) under the influence of anthropogenic warming in the past century, and this increase will continue during the twenty-first century based on the results from climate model projections. The increased predictability is due to the stronger MJO amplitude, more regular oscillation patterns and more organised eastward propagation under global warming.

Sea level variability along the U.S. East coast

Coastal flooding is one of the major threats to nearshore regions, and it has become more frequent along the U.S. east coast in recent decades. The year-to-year (i.e., inter-annual) sea level variations, superimposed on decadal fluctuations and climate change-induced global sea level rise, have significant impacts on the frequency and spatial variation of coastal flooding. The factors that can drive the year-to-year sea level variations are complex. Local forcings arise for example from atmospheric wind and sea level pressure in the nearshore regions. Other sea level signals are remotely forced and propagate to the U.S. east coast from the open ocean and from the subpolar north Atlantic down via the western boundary. In our recent study (Zhu et al 2023a), we found that during the satellite altimetry era from 1993-2019, local wind and sea level pressure play more important roles than other remote forcing in driving the year-to-year coastal sea level variations in the Mid-Atlantic Bight and Gulf of Maine, while both local and remote forcings are important in the South Atlantic Bight.

The role of local forcings, however, is non-stationary with time, with a significantly increased impact on coastal sea level in the Mid-Atlantic Bight and Gulf of Maine especially during boreal summer season in recent decades (1990-2020) compared to earlier decades (1959-1989) (Zhu et al. 2023b). The enhanced impact of local forcings in recent decades results mainly from the increased influence of atmospheric sea level pressure associated with the North Atlantic Oscillation (NAO), a dominant inter-annual climate variability pattern that has large influence on the U.S. and European climate. A stronger NAO-associated low sea level pressure anomalies is centred around the Mid-Atlantic Bight region in recent decades, resulting in a larger impact on coastal sea level compared to earlier decades.

  • Zhu, Y., W. Han, M. Alexander, and S-K Shin, 2023a: Interannual Sea Level Variability Along the U.S. East Coast During Satellite Altimetry Era: Local versus Remote Forcing. Journal of Climate, DOI: https://doi.org/10.1175/JCLI-D-23-0065.1
  • Zhu Y., W. Han, M. Alexander, 2023b: Nonstationary Roles of Regional Forcings in Driving Low-frequency Sea level Variability Along the U.S. East Coast since the 1950s. Geophysical Research Letters, https://doi.org/10.1029/2023GL104191
  • Zhang, L., C. Wang, W. Han, M.J. McPhaden, A. Hu, and W. Xing, 2023: Emergence of Central Atlantic Nino. Science Advances, DOI: https://doi.org/10.1126/sciadv.adi5507
  • Du, D., A. Subramanian, W. Han, W. Chapman, J. Weiss and E. Bradley, 2023: Increase in MJO predictability under global warming. Nature Climate Change, https://doi.org/10.1038/s41558-023-01885-0 

Also, have a listen to Professor Han’s Pro ISSI talk here: www.issibern.ch/pro-issi-weiqing-han/

Inter-planetary Trade Routes

Group photo of the interdisciplinary conference participants including ISSI Director Maurizio Falanga. (Image source: World Trade Institute, WTI)
Group photo of the interdisciplinary conference participants including ISSI Director Maurizio Falanga. (Image source: World Trade Institute, WTI)

Pioneering an Interdisciplinary Approach to Space Commerce

The recent conference, “The Economics and Law of Space-Based Commerce,” convened here in Bern, Switzerland, brought together key stakeholders and researchers from diverse fields, including economics, law, politics, and space sciences. The event tackled pressing questions surrounding the governance framework for private actors in space commerce.

Participants delved into the applicability of current economic concepts to outer space activities and examined the complexities of international economic law in this emerging domain. From exploring the potential application of existing trade, investment, and tax laws to space-based commerce to identifying new areas for multidisciplinary research, the conference provided a platform for rich discussions and insights.

Jointly hosted by the World Trade Institute (WTI), the University of Bern, and ISSI, with support from the Swiss Institute of Comparative Law (SICL), COSPAR, and the University College Dublin (UCD), this event aimed to pave the way for future collaborations and advancements in understanding the economics and law of space commerce. Representatives from the Swiss Space Office (SSO) and the Swiss Federal Department of Foreign Affairs (EDA) also contributed to the vibrant exchange of ideas.

To read more about it, go to: https://www.linkedin.com/pulse/space-based-commerce-new-interdisciplinary-approach-6bofe/

Observing Earth’s Vulnerabilities

Observing potential climate tipping elements following Lenton et al. (2019), where rising global atmospheric temperatures could cause irreversible change to the Earth system. Figure by Fabio Crameri and adjusted from https://s-ink.org/climate-change-tipping-points.
Observing potential climate tipping elements following Lenton et al. (2019), where rising global atmospheric temperatures could cause irreversible change to the Earth system. Figure adjusted from s-ink.org/climate-change-tipping-points.

ISSI Forum sparks breakthrough guidance for remote sensing collaborations to monitor climate tipping points

In a thoughtful collaboration, an interdisciplinary group of researchers headed by Professor Tim Lenton at the University of Exeter have published a paper offering crucial insights into how to better understand climate tipping points and the role of remote sensing in detecting and monitoring these critical transitions in the Earth’s system. The paper, originating from a Forum held at the International Space Science Institute (ISSI) in Bern, Switzerland, emphasises the minimum criteria for applying remote sensing data to diverse tipping phenomena.

Remote sensing has already provided vital evidence, from tracking the loss of Antarctic Peninsula ice shelves to revealing alternative stable states in vegetation. By combining Earth Observation data and models, the researchers demonstrate the potential for improved predictions of abrupt events, such as droughts or ecosystem loss, with significant implications for food security and regional policy-making. The collaboration highlights the societal benefits of enhanced information on potential tipping points, offering a roadmap for resilience sensing and early warning to navigate the challenges posed by climate change. The ISSI Forum fostered this cross-disciplinary effort, underscoring the importance of collaborative platforms in advancing climate science.

For more details, access the paper here: Lenton, T.M., Abrams, J.F., Bartsch, A. et al. Remotely sensing potential climate change tipping points across scales. Nat Commun 15, 343 (2024). https://doi.org/10.1038/s41467-023-44609-w

Studying the Solar Mysteries

Normalized 3D electron density distribution resulting from tomographic inversion of polarized-brightness coronagraph images using the six-spacecraft “Solar Ring” configuration. Figure adjusted from ISSI Bern workshop results by Palmerio, Barnes, et al.
Normalized 3D electron density distribution resulting from tomographic inversion of polarized-brightness coronagraph images using the six-spacecraft “Solar Ring” configuration. Figure adjusted from ISSI Bern workshop results by Palmerio, Barnes, et al.

A Trailblazing Journey to Decode Coronal Mass Ejections in 3D

In a novel cross-disciplinary effort, the ISSI Team around Erika Palmerio and David Barnes is revolutionizing our understanding of Coronal Mass Ejections (CMEs), powerful solar eruptions with significant space weather impacts on Earth. Focusing on the often-overlooked tomography technique, the team utilizes state-of-the-art magnetohydrodynamic simulations and synthetic white-light data to overcome observational limitations. By placing virtual spacecraft strategically, they generate synthetic images, reconstructing CME structures through discrete tomography.

The findings based on their modelling reveal a complex, irregular front in contrast to traditional assumptions. The team aims to evaluate the impact of 3D reconstructions on space weather predictions, comparing them with conventional forward-modelling techniques. With plans to extend analyses to heliospheric imagery, their work promises groundbreaking insights into CME behavior and improved forecasting methods. Stay tuned for further revelations from this innovative endeavor tackled at ISSI Bern!

See the full team report here: Tomographic Inversion of Synthetic White-Light Images: Advancing Our Understanding of CMEs in 3D