Thursday, May 28, 2026

SPACE/COSMOS

Listening to Sun's 'heart' hints our star could be changing




Royal Astronomical Society

Sun cycle 

image: 

A split image showing an active Sun during solar maximum (on the left, taken in 2014) and a quiet Sun during solar minimum (on the right, taken in 2019).

view more 

Credit: NASA/SDO





The Sun's internal 'biorhythm' – which plays a critical role in the space weather we experience on Earth – has mysteriously changed over the past 40 years, a new study suggests.

Listening to tiny sound waves inside our star's 'heart' led researchers to discover that it may be entering "a different mode of behaviour". They now need to explore what this means.

The research, published today in Monthly Notices of the Royal Astronomical Society, is of particular significance to space weather.

Solar activity rises and falls in 11‑year cycles, producing solar flares, and ejections of highly charged particles and coronal mass ejections that give rise to geomagnetic storms and aurorae.

This activity, and its cyclic variation, has its origins in the Sun's interior, in processes that regenerate and reorganise the Sun's magnetic field.

Understanding what drives the solar cycle is therefore crucial for making predictions of space weather, which can disrupt satellites, communications, GPS systems and power grids on Earth.

Traditional measures of solar activity track these emissions and other surface phenomena like sunspots, but they do not look under the solar surface. However, by 'listening' to tiny sound waves inside the Sun – a technique known as helioseismology – it is possible to do just that. By tracking changes in the otherwise hidden solar interior, the team found a different picture emerged of the Sun's activity over the past few cycles to the one given by the traditional measures.

Using almost 40 years of helioseismic data from six telescopes around the world in the Birmingham Solar Oscillations Network (BiSON), the international team of researchers uncovered a gradual change in structure just beneath the surface that has spanned multiple cycles, with the current solar cycle 25 showing particularly strong signatures of these changes.

They discovered that solar magnetic activity is being squeezed into an increasingly shallow layer just below the visible surface, signposting long-term changes to the Sun's active behaviour.

Lead author Professor Bill Chaplin, from the University of Birmingham, said: "The Sun has its own 'active biorhythm' creating rising and falling magnetic activity that shapes space weather. However, traditional surface measures don't capture the full story – that the Sun may be entering a different mode of behaviour unfolding over decades.

"We have uncovered evidence of systematic changes in the solar activity cycle. Crucially, magnetic activity is becoming more tightly confined near the surface with each cycle. This is the first such discovery and would have been impossible without the long BiSON observations."

The researchers analysed the p-mode oscillations – formed by global sound waves inside the Sun – whose frequencies shift in response to solar magnetic activity. This allowed them to determine how the Sun's internal structure changed across solar cycles 22–25, from 1987 to 2025.

They grouped oscillations into low-, mid-, and high-frequency bands to probe different depths beneath the solar surface. The team then compared these frequency shifts with traditional measures of solar activity to reach three main conclusions:

  • Evidence of changing behaviour – the link between oscillation frequencies and traditional activity measures has shifted significantly since Cycle 23, indicating long-term evolution in the Sun's internal processes.
  • Surface confinement of structural changes – the combined behaviour of low-, mid-, and high-frequency modes shows that solar-cycle-driven structural changes are becoming increasingly confined to shallow layers, within 1,000km of the Sun's surface.
  • Reinterpreting the strength of the latest cycle – Cycle 25 appears weaker in traditional surface indicators but comparably strong when seen in the high-frequency helioseismic data.

Professor Sarbani Basu, from Yale University, said: "We discovered that the relationship between internal solar oscillations and surface activity has evolved over the past few cycles.

"This trend cannot be explained simply by weaker magnetic fields. Instead, it indicates a structural reorganisation of how the Sun's magnetic activity is stored beneath the surface."

Ongoing collection and analysis of BiSON solar data over what remains of Cycle 25 and into the upcoming Cycle 26 will be crucial in determining whether the changes discovered in the Sun's activity point to a sustained, systematic change in solar magnetic behaviour.

ENDS


Images & captions

Solar biorhythm

Caption: As the Sun's activity varies over each 11-year solar cycle – from periods of high activity (solar maxima) to low activity (solar minima) – so the Sun's oscillations, which are due to sound waves in the Sun's interior, increase and decrease in frequency. The oscillations therefore track and probe the Sun's active biorhythm.

Credit: W. J. Chaplin

 

Sun cycle

Caption: A split image showing an active Sun during solar maximum (on the left, taken in 2014) and a quiet Sun during solar minimum (on the right, taken in 2019).

Credit: NASA/SDO


Solar biorhythm 

As the Sun's activity varies over each 11-year solar cycle – from periods of high activity (solar maxima) to low activity (solar minima) – so the Sun's oscillations, which are due to sound waves in the Sun's interior, increase and decrease in frequency. The oscillations therefore track and probe the Sun's active biorhythm.

Credit

W. J. Chaplin


Further information

The paper ‘Subsurface structural changes associated with successive 11-yr solar activity cycles have been progressively more confined near the surface: new helioseismic results on Cycles 22–25 from BiSON’ by Chaplin et al. has been published in Monthly Notices of the Royal Astronomical Society. DOI: 10.1093/mnras/stag847.


Notes for editors

About the Royal Astronomical Society

The Royal Astronomical Society (RAS), founded in 1820, encourages and promotes the study of astronomy, solar-system science, geophysics and closely related branches of science.

The RAS organises scientific meetings, publishes international research journals, recognises outstanding achievements by the award of medals and prizes, maintains an extensive library, supports education through grants and outreach activities and represents UK astronomy nationally and internationally. Its more than 4,000 members (Fellows), a third based overseas, include scientific researchers in universities, observatories and laboratories as well as historians of astronomy and others.

The RAS accepts papers for its journals based on the principle of successful peer review, following which experts on the Editorial Boards accept the papers for publication. The Society issues press releases based on a similar principle, but the organisations and scientists concerned have overall responsibility for their content.

Keep up with the RAS on Instagram, Bluesky, LinkedIn, Facebook and YouTube.

Download the RAS Supermassive podcast

 

About the University of Birmingham

The University of Birmingham is ranked amongst the world's top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 40,000 students from over 150 countries.

England's first civic university, the University of Birmingham is proud to be rooted in of one of the most dynamic and diverse cities in the country. A member of the Russell Group and a founding member of the Universitas 21 global network of research universities, the University of Birmingham has been changing the way the world works for more than a century.

Scientists show how baby stars’ cradles get their radial shape



New 3D simulations show a dying star's last shockwave can weave a star-forming hub into shape




Kyushu University

Observed hub-filament system compared with simulation results 

image: 

The left panel shows a hub-filament system observed in an actual star-forming region; the right shows the structure produced by this study's 3D simulation. Both show multiple elongated filaments of gas radiating toward a dense central hub. The study shows that this characteristic pattern can emerge when a fast interstellar shockwave strikes a molecular cloud with a curved magnetic field.

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Credit: Left: M. S. N. Kumar, ESA/Herschel, NASA/JPL-Caltech (Spitzer); Right: S. Nozaki & S. Inutsuka





Fukuoka, Japan—The universe is full of fascinating structures, and some of the most striking take shape inside the giant clouds where stars are born. There, streams of gas appear to converge from all directions toward a dense central hub, like spokes meeting at the center of a wheel.

Now, researchers from Kyushu University and Nagoya University have used 3D computer simulations to reveal the physics behind these elegant structures. The study was published in March 2026 in The Astrophysical Journal Letters.

“Stars are born inside molecular clouds—vast, cold clouds of gas that drift through space,” says Shingo Nozaki, a doctoral student at Kyushu University's Graduate School of Sciences, and a Research Fellow of the Japan Society for the Promotion of Science (JSPS). “But they only form in the coldest and densest parts of those stellar nurseries, where gas can collapse under its own gravity. In some of these star-forming regions, gas is organized into characteristic hub-and-spoke patterns known as Hub-Filament Systems (HFS).”

How this radial pattern forms, however, has long remained unclear. At a workshop at Kyushu University last summer, Nozaki and Shu-ichiro Inutsuka of Nagoya University began exploring one possible explanation: what happens when an external shock hits a gas cloud with a pinched magnetic field shape?

Using ATERUI III, an astronomy-dedicated supercomputer operated by the National Astronomical Observatory of Japan, they conducted a 3D magnetohydrodynamic simulation, a computational method that models how gas and magnetic fields evolve together over time.

As a rough analogy, Nozaki pictures the initial molecular cloud as a dorayaki—a Japanese pancake that's thick in the middle and thin at the edges. A vertical magnetic field runs through the cloud, while gravity pulls the field inward at the center, bending it into an hourglass shape. The team then introduced a cosmic disturbance into the cloud, mimicking the kind of disturbance triggered by a supernova remnant or by expanding gas around massive stars.

The results show several elongated structures that develop toward a dense central region, closely resembling observed HFSs. As the magnetic field lines curve inward, the shock wave strikes different parts of the cloud at different angles, creating what physicists call oblique shocks. These shocks strengthen parts of the magnetic field, forming invisible channels that guide compressed gas into long, narrow filaments converging toward the center.

The simulation also revealed that gas does not flow uniformly into the hub. Dense gas within the filaments moves steadily inward, accelerating as it approaches the center, while the low-density gas between filaments stays mostly still. This indicates that the main carriers of mass to the central region are the shock-produced dense filaments, not the cloud as a whole, offering insights into why star formation efficiency remains limited to a few percent.

The team notes that this study focused on a geometrically regular type of HFS, while many observed systems are more asymmetric and complex. Next, they plan to systematically vary the shock direction and strength; the cloud’s density structure; and the magnetic field geometry. This will help them connect different cloud environments to the formation of various massive stars and clusters, and more broadly, to understand how star formation proceeds across galaxies.

“There are two main sources of these shock waves: radiation-driven ‘bubbles’ from newly formed massive stars, and expanding supernova remnants formed when a massive star reaches the end of its life,” adds Nozaki. “There is something almost like a life cycle in this. What a star leaves behind can go on to shape the next cradle of stars.”

###

For more information about this research, see " An Origin of Radially Aligned Filaments in Hub-filament Systems," Shingo Nozaki and Shu-ichiro Inutsuka, The Astrophysical Journal Letters, https://doi.org/10.3847/2041-8213/ae4c84

About Kyushu University 
Founded in 1911, Kyushu University is one of Japan's leading research-oriented institutions of higher education, consistently ranking as one of the top ten Japanese universities in the Times Higher Education World University Rankings and the QS World Rankings. Located in Fukuoka, on the island of Kyushu—the most southwestern of Japan’s four main islands—Kyushu U sits in a coastal metropolis frequently ranked among the world’s most livable cities and historically known as Japan’s gateway to Asia. Its multiple campuses are home to around 19,000 students and 8,000 faculty and staff. Through its VISION 2030, Kyushu U will “drive social change with integrative knowledge.” By fusing the spectrum of knowledge, from the humanities and arts to engineering and medical sciences, Kyushu U will strengthen its research in the key areas of decarbonization, medicine and health, and environment and food, to tackle society’s most pressing issues.



Observed hub-filament system compared with simulation results [VIDEO] 

The left panel shows a hub-filament system observed in an actual star-forming region; the right shows the structure produced by this study's 3D simulation. Both show multiple elongated filaments of gas radiating toward a dense central hub. The study shows that this characteristic pattern can emerge when a fast interstellar shockwave strikes a molecular cloud with a curved magnetic field.

Credit

Shingo Nozaki / Kyushu University

Chang’e-5 Regolith Studies Reveal Nanoscale Space-Weathering Processes

Formation mechanism of multilayered structure containing npFe0 particles CREDIT: NIGPAS

May 28, 2026 
By Eurasia Review


On the Moon, the lack of atmosphere and accompanying features such as biological activity, oxygen-rich air, flowing water and rain, wind, and most erosion allows the lunar regolith to preserve a long-term record of surface processes in the space environment.

Such processes, which have a major effect on airless bodies such as the Moon, Mercury, and asteroids, include solar wind irradiation, micrometeorite bombardment, impact melting, sputter deposition, and rapid quenching—all of which continuously alter the structure, composition, and optical properties of surface materials.

Understanding these processes at the micro- and nanoscale is essential for interpreting lunar space weathering, remote-sensing spectra, and the form and distribution of surface resources.

To enhance this understanding, a collaborative team jointly led by Prof. YIN Zongjun from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), together with Profs. SHEN Bing and ZHOU Jihan from Peking University, has conducted systematic studies of impact-glass particles associated with Chang’e-5 lunar regolith grains.


The findings were published in the Journal of Geophysical Research: Planets and PNAS. Together, these studies focus on the same type of Chang’e-5 impact glass, revealing the nanoscale evolution of lunar surface materials through two complementary processes: impact-induced silicate phase separation and the formation of nanophase metallic iron.

In the Journal of Geophysical Research: Planets study, the researchers examined Chang’e-5 impact glass using aberration-corrected transmission electron microscopy, scanning transmission electron microscopy, and spectroscopic analyses.

They identified Fe-rich nanodroplets within Si-rich glass, as well as Si-rich nanodroplets within Fe-rich glass. The nanodroplets were amorphous, i.e., lacked a regular crystal structure, and were found in clusters that had partially merged and grown. The results suggest that micrometeorite impacts not only induce local melting of lunar regolith, but can also trigger silicate liquid immiscibility on extremely short timescales, with rapid quenching preserving the transient phase-separated structures in impact glass where different materials separated from one another.

Building on this work, the PNAS study examined nanophase metallic iron (nanophase Fe0, npFe0) in the impact glass, which is a major product of lunar space weathering. It also plays a key role in modifying the reflectance spectra of lunar soils.

Using electron tomography alongside energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy, the researchers directly resolved the three-dimensional distribution, morphology, local abundance, and iron valence states of npFe0 at the nanometer scale.

In one reconstructed volume, 1,506 npFe0 particles were identified, with an average diameter of approximately 3.4 nm and a median diameter of approximately 2.9 nm. Different layers showed distinct particle sizes, number densities, and Fe⁰ volume fractions, with the Fe⁰ volume fraction in a local large-particle layer reaching up to 30 vol%.

To determine how the nanoparticles formed in different regions, the researchers combined structural reconstructions with elemental and iron valence-state analyses. They also introduced a parameter, ξ, to evaluate the contribution of external electrons during iron reduction.

The study showed that the sulfur-rich layer containing irregular large particles mainly originated from iron sulfide decomposition. It also showed that several layers with high concentrations of small particles were dominated by Fe2+ disproportionation—a process in which Fe2+ is simultaneously oxidized and reduced. The near-surface region exhibited evidence of later modification due to solar wind irradiation, promoting glass-structure modification and npFe0 particle ripening.


The researchers further estimated that metallic iron in mature impact-glass domains could reach 7.1 wt%, substantially exceeding previous bulk-soil estimates for Chang’e-5 samples. This result highlights significant microscale heterogeneity in the distribution of npFe0 in lunar regolith.

Together, the two studies demonstrate that Chang’e-5 impact glass simultaneously records several related processes—impact melting, silicate liquid immiscibility, redox reactions, sulfide decomposition, and solar wind modification. Using electron tomography and high-resolution spectroscopic techniques, the researchers were able to overcome the limitations of conventional two-dimensional imaging and quantitatively reconstruct nanoscale structures and their formation histories in three dimensions.

The findings provide new sample-based insights into the spectral evolution of the Moon and other airless bodies, the processes responsible for forming lunar impact glass, and the distribution and physical state of iron resources on the lunar surface.

 

Heat lingers on in our cells


Temperature behaves differently in the unique liquid environment inside the cell compared to other fluids, in a way scientists are still trying to understand




University of Tokyo

Not diffusing the situation. 

image: 

An illustration of the mechanism by which temperature in cells remains and the biological effects it can have.

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Credit: K. Okabe et al. 2026





Living cells cool much slower than our current understanding of heat conduction can explain, according to new research from the University of Tokyo. Researchers used two techniques — high-speed temperature mapping and artificial heating — to observe how heat dissipated from living cells and similar-sized artificial, fluid-filled sacs (liposomes). While heat dispersed quickly from the artificial liposomes as expected, cells cooled significantly more slowly due to other biomolecules within the cell. Understanding the process behind slower heat dissipation within cells could affect how we treat conditions linked to changes in body temperature, such as epilepsy, inflammation and cancer.
 

Do you tend to run a little hot or are you cool as a cucumber? Your internal body temperature is the byproduct of all the work your cells do to keep you living, moving and thriving. More recently, researchers have found that spontaneous heat generation in our cells, which can change by as much as 1-2 degrees Celsius, appears to play an important role in driving some key cell-based activities and functions. So far, this includes changing neural stem cells into neurons and the heat shock response, which protects stressed cells from damage. 

As our cells are sacs of mostly jellylike fluid, it is not unreasonable to think that the heat they generate would behave according to the typical laws of physics which apply to all fluids. However, a paper published in 2012 provided the world’s first map of temperature distribution within a cell, along with a surprising revelation.
  
“Our results showed a massive gap between the ‘laws of physics’ and the ‘reality of life’ in terms of how temperature changes within a cell,” explained Project Associate Professor Kohki Okabe from the Graduate School of Pharmaceutical Sciences, co-author on this latest research and lead author of the 2012 paper. “We felt driven to solve this contradiction ourselves and have now found that cells are highly specialized environments that handle heat in a very unique way.”

The team used an ultrasensitive microscope (called a high-speed fluorescence lifetime imaging microscope), along with a custom-made thermometer to map temperature changes in detail in real time. After heating part of a cell with an infrared laser, they monitored the cooling process with millisecond precision. The team performed the same tests on artificial, cell-like sacs of fluid (liposomes). They then compared the temperature changes inside the cells and the liposomes with their model-based predictions. 

According to conventional physics, heat should spread out (diffuse) from a fluid very rapidly, which the team saw happen with the liposomes. However, they found that inside a cell, heat tended to “stay put.” Diffusion was not only slow, but it also depended on where within the cell was heated and the surrounding molecules. From their observations, they concluded that the slow rate of change was an intrinsic property of the cells, and not due to a side effect of the research method.

“The phenomenon of ‘nonspreading heat’ is so unprecedented we could not rely on existing textbooks to decipher the physical mechanism behind what we saw. This phenomenon completely flips our conventional understanding on its head,” said Okabe.

Next, the researchers want to delve deeper into the mechanisms behind this slow heat transfer. “We believe that this trapped heat is not just waste; it acts as a concentrated energy source that powers cellular functions,” explained Okabe. “By redefining heat as an ‘active signal’ that cells use to control themselves — rather than just a byproduct — we hope to unlock new ways to understand life and develop innovative medical treatments.”

 

Staying hot. 

Temperature changes in a cell after heating captured by fluorescence imaging. According to conventional knowledge, it would be expected that heat would dissipate almost instantly into surrounding areas, but it doesn’t.

 

Credit

K. Okabe et al. 2026


--- --- --- --- --- --- 

Paper:
Masaharu Takarada, Ryo Shirakashi, Masahiro Takinoue, Motohiko Ishida, Masamune Morita, Hiroyuki Noji, Kazuhito V. Tabata, Takashi Funatsu, and Kohki Okabe. “Non-diffusive slow heat dissipation induces high local temperature in living cells.” Nature Communications. Date: May 28th, 2026. DOI: 10.1038/s41467-026-71878-y.

Funding
This work was supported by PRESTO and CREST of JST, JSPS KAKENHI (18H03981, 20H05785, 21J14440, 24H02306, and 25K02236), Life Science Foundation of Japan, and Brain Science Foundation.

Conflicts of Interest:
The authors declare there are no conflicts of interest.

Useful links
Graduate School of Pharmaceutical Sciences: https://www.f.u-tokyo.ac.jp/en/ 



About The University of Tokyo:
The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 5,000 international students. Find out more at www.u-tokyo.ac.jp/en/ or follow us on X (formerly Twitter) at @UTokyo_News_en.
 

 

Arctic Ocean food chain disrupted as key tipping point passed



University of Edinburgh
Polar research vellel in Fram Strait 

image: 

The polar research vessel RV Kronprins Haakon in Fram Strait, Arctic Ocean.

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Credit: Lawrence Hislop/Norwegian Polar Institute





An irreversible shift in the chemical make-up of the Arctic Ocean driven by climate change is disrupting the region’s food chain, a study suggests.

Widespread loss of Arctic sea ice has led to a sharp fall in levels of a key nutrient, affecting populations of plankton, fish, seabirds and marine mammals, researchers say.

Their analysis reveals that exposure to sunlight of vast shallow regions of the ocean previously covered by ice fuels a process that breaks down the nutrient – nitrate – and removes it from seawater.

Nitrate is vital for the growth of plankton at the base of the Arctic food chain, and reduced levels of the nutrient limit the amount of life the ecosystem can support, the team says.

Dwindling levels of nitrate could also reduce the Arctic Ocean’s capacity to store carbon, as plankton play a key role in capturing it from the atmosphere through photosynthesis, they add.

While recent studies have reported changes in animal populations in Arctic waters, the causes were poorly understood as there have been few in-depth analyses of the ocean’s chemical make-up.

Now, researchers from the University of Edinburgh have gained new insights into the changing nutrient levels in the Arctic Ocean by analysing data spanning a 20-year period.

The team assessed more than two decades of sampling data from Fram Strait, the main gateway through which Arctic waters flow into the Atlantic.

Their analysis reveals a clear shift from 2009 onwards, with nitrate levels in waters leaving the Arctic falling steadily. The drop in nitrate levels coincided with a drastic reduction in Arctic sea ice that began around the same time, the team says.

The extensive loss of sea ice ramped up a process that converts nitrate to nitrogen gas – called benthic denitrification – in shallow continental shelves that underly nearly half of the Arctic Ocean, the team says.

The shift to nitrate-limited conditions suggests the Arctic Ocean may only be able to support smaller species of plankton in the future, meaning less food is available moving up the food chain.

Since the change in nutrient conditions is driven by ongoing sea ice loss, it is very unlikely the Arctic Ocean will ever revert to its previous state, researchers say.

Further research is needed to understand the possible wider effects that changes in Arctic waters could have on marine populations in other parts of the world’s oceans, including the North Atlantic.

The research, published in the journal Communications Earth & Environment, was supported by the Natural Environment Research Council (NERC)’s Changing Arctic Ocean project.

The work also involved researchers from the Norwegian Polar Institute, Scottish Association for Marine Science, Technical University of Denmark and Alfred-Wegener-Institut, Germany.

Marta Santos-García, a PhD student in the University of Edinburgh’s School of GeoSciences, who co-led the study, said: “For years, sea-ice loss in the Arctic Ocean was expected to increase phytoplankton growth because more sunlight could reach surface waters. Our findings suggest that this relationship has changed: the Arctic Ocean appears to have shifted from a system mainly limited by light to one increasingly limited by nitrate availability, with far-reaching consequences for marine ecosystems, food chains and the role of the Arctic in the Earth’s climate.”

Professor Raja Ganeshram, of the University of Edinburgh’s School of GeoSciences, who has led the study over the last two decades, said: “The changes we report suggest that the Arctic Ocean ecosystem passed a tipping point around 2009. How this change cascades through the food chain needs to closely monitored as this has profound implications for us, including on commercial fishing in the North Atlantic Ocean.”

 

Sensitivity of Antarctic ice to climate change sharply increased after Ice Age shift 1 million years ago




Institute for Basic Science
Figure 1. Relationship between atmospheric CO2 concentration and Antarctic ice volume 

image: 

Top right panel shows the model simulation of Antarctic ice sheet volume change covering the last 3 million years. Bottom right panel represents the relationship between atmospheric CO₂ concentration and Antarctic ice volume changes. Blue and orange lines show nonlinear fits for 1-0 million years ago and 3-1 million years ago, respectively, with shaded bands indicating the 95% uncertainty range. Maps on the left show representative Antarctic ice elevation changes under high-, transitional-, and low-CO₂ states.

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Credit: Institute for Basic Science





A new study published in the journal Nature Geoscience [1] by researchers at the IBS Center for Climate Physics (ICCP) at Pusan National University in South Korea shows that the Antarctic ice sheet became more sensitive to climate forcing following a major shift in Earth’s ice age cycles about one million years ago, providing new insight into how ice sheets respond to long-term climate change.

Antarctica currently holds the largest ice mass on Earth and plays a key role in global sea level change. About one million years ago, Earth’s climate system underwent a major shift, with ice ages becoming longer and more intense. This transition, known as the Mid-Pleistocene Transition, fundamentally altered the behavior of large ice sheets, yet how they responded to this change remains poorly understood. A key challenge has been the lack of long-term, realistic temperature and precipitation data needed to run ice sheet models under such conditions.

To overcome this limitation, the researchers used a realistic paleoclimate computer simulation [2], recently conducted at the ICCP, that reproduces the global climate history over the last 3 million years. Temperature and rainfall data from this simulation were then used as input for the Penn State University ice-sheet–ice-shelf model. This model simulates changes in ice sheet flow, temperature, and height for the Northern Hemisphere ice sheets and Antarctica. It also captures the dynamics and movement of floating ice shelves, such as in the Ross and Weddell Seas. Running the ice-sheet model on one of South Korea’s fastest computers dedicated to basic science, the researchers obtained a physically consistent and spatially continuous representation of the global ice-sheet evolution under time-evolving climate conditions.

The simulation reveals that following the Mid-Pleistocene Transition, the Antarctic ice sheet entered a new dynamical regime. In particular, the results identify a critical atmospheric CO2 level of around 240 parts per million, below which the amplitude of Antarctic ice variations suddenly increases in response to changes in atmospheric and ocean temperatures (Fig. 1).

“After this transition, the Antarctic ice sheet reacts much more strongly to changes in climate forcing. This indicates that the system does not evolve gradually but instead becomes more responsive after crossing a particular threshold in the climate system,” said Dr. YUN Kyung-Sook, researcher at the IBS Center for Climate Physics and lead author of the study.

In the computer model simulation, the accelerated Antarctic ice growth after the 1 million years ago can be attributed to a combination of factors: i) colder glacial ocean temperatures, which reduce melting of the Antarctic ice sheet below sea level, ii) lower global sea level (~50-100 m below present), which reduces the pressure on the bedrock below the ice shelves, leading to a slow uplift which further promotes ice thickening along the coast of Antarctica. Working in unison, these processes helped establish the larger and more persistent Antarctic ice sheets characteristic of later ice age cycles (Fig. 2).

“Our findings suggest that the Antarctic ice sheet was more sensitive to external forcings than previously assumed. This also raises important questions about its future response to global warming,” said Prof. Axel TIMMERMANN, Director of the IBS Center for Climate Physics and co-author of the study.

The study highlights that ice sheets do not respond linearly to climate forcing but instead can undergo sharp shifts that drastically alter their sensitivity to external factors. Understanding these changes is critical for improving projections of future sea level rise.

Figure 2. Antarctic ice sheet response to climate and sea level 

Ross Sea ice-shelf transect for low-CO₂ conditions, corresponding to high sensitivity to forcings: (left) climate contribution, (middle) sea-level contribution, and (right) combined impacts of climate and sea-level changes.

Credit

Institute for Basic Science

 

Impact of climate change on mental health: webinar by the German and South African national academies on an emerging field of research




Leopoldina


Extreme heat, natural disasters, food insecurity: climate change is known to have serious consequences for human physical health. In many places, scientific findings are being used to develop adaptation strategies and to mitigate the consequences of climate change for human health. But what about mental health? Research in this field is still in its early stages. As a result, climate, health and development policy also lacks strategies for prevention and treatment. To draw attention to this area of research, the German National Academy of Sciences Leopoldina and the Academy of Science of South Africa (ASSAf) are opening the discussion in an international virtual panel discussion on Tuesday, 9 June. We cordially invite you to this event and would appreciate an announcement of this date in your medium.

Leopoldina International Virtual Panel (LIVP) – in cooperation with the Academy of Science of South Africa (ASSAf)
“From Planetary Change to Psychological Impact: Understanding and Responding to the Mental Health Effects of Climate Change”
Tuesday, 9 June 2026, 12 noon to 1:15 p.m. (CEST)
Online via Zoom

Climate-related stressors can affect mental health both directly and indirectly. They frequently interact with existing social inequalities and increase the vulnerability of population groups that are already marginalised. In the webinar, experts from medicine, psychology, and geography will provide an overview of the links between climate change and mental health. They will also discuss specific interdisciplinary perspectives from South Africa and Germany and consider which aspects of mental health could be integrated into climate and health strategies. The panellists are:

  • Professor Dr Caradee Wright, South African Medical Research Council, Pretoria/South Africa
  • Professor Dr Frauke Kraas, University of Cologne/Germany
  • Professor Dr Simone Kühn, Max Planck Institute for Human Development, Berlin/Germany
  • Professor Dr Tholene Sodi, University of Limpopo in Polokwane/South Africa

The webinar is aimed at all those with a professional interest in the topic. It will take place online via Zoom and will be held in English. Further information about the event and the link for the required registration can be found at: https://www.leopoldina.org/en/publications-and-dates/events/detail/from-planetary-change-to-psychological-impact-understanding-and-responding-to-the-mental-health-effects-of-climate-change

The webinar is being held in preparation for the joint workshop “Climate Change and Mental Health: Comparative Risk Pathways, Vulnerability, and Resilience”, which ASSAf and the Leopoldina will host in South Africa from 8 to 10 September: https://www.leopoldina.org/en/publications-and-dates/events/detail/climate-change-and-mental-health-comparative-risk-pathways-vulnerability-and-resilience

The Leopoldina works closely with the South African Academy of Sciences (ASSAf). Together they promote scientific exchange, organise symposia and workshops and participate in international networks. Further information: https://www.leopoldina.org/en/tasks/networking/global-partners/south-africa

Journalist would like to attend should register by email at presse@leopoldina.org.  

All events of the Leopoldina International Virtual Panel Series (YouTube): https://www.youtube.com/playlist?list=PLaCuDJ8AkAoMm2LcRTOEImcfW2L3IcBiJ

About the German National Academy of Sciences Leopoldina
As the German National Academy of Sciences, the Leopoldina provides independent science-based policy advice on matters relevant to society. To this end, the Academy develops interdisciplinary statements based on scientific findings. In these publications, options for action are outlined; making decisions, however, is the responsibility of democratically legitimized politicians. The experts who prepare the statements work in a voluntary and unbiased manner. The Leopoldina represents the German scientific community in the international academy dialogue. This includes advising the annual summits of Heads of State and Government of the G7 and G20 countries. With around 1,700 members from more than 30 countries, the Leopoldina combines expertise from almost all research areas. Founded in 1652, it was appointed the National Academy of Sciences of Germany in 2008. The Leopoldina is committed to the common good.