Much more than a world first image of radioactive cesium atoms

UNIVERSITY OF HELSINKI

 

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FIGURE 1. (LEFT) A STRUCTURE MODEL OF POLLUCITE AND A SIMULATED HAADF-STEM IMAGE USING MACTEMPAS. (RIGHT) A HIGH RESOLUTION HAADF-STEM IMAGE OF IRON-RICH POLLUCITE IN THE CSMPS. THE CS ATOMS IN THE IMAGE APPEAR AS BRIGHT SPOTS (CIRCLED IN THE IMAGE). APPROXIMATELY HALF OF THE CS ATOMS IN THE STRUCTURE ARE RADIOACTIVE. RADIOACTIVE CS ATOMS HAVE NOT BEEN IMAGED BEFORE FROM ENVIRONMENTAL SAMPLES.

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CREDIT: KANAKO MIYAZAKI ET. AL.

Thirteen years after the nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP), a breakthrough in analysis has permitted a world first: direct imaging of radioactive cesium (Cs) atoms in environmental samples.

The groundbreaking analysis, completed by a team of researchers in Japan, Finland, America, and France, analyzing materials emitted from the damaged FDNPP reactors, reveals important insights into the lingering environmental and radioactive waste management challenges faced in Japan. The study, titled ““Invisible” radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant” has just been published in the Journal of Hazardous Materials. It can be accessed here for free.

The Fukushima Daiichi Meltdowns: A Continuing Engineering and Environmental Puzzle

In 2011, after the Great Tōhoku Earthquake and Tsunami, 3 nuclear reactors at the FDNPP underwent meltdowns due to a loss of back-up power and cooling. Since then, extensive research efforts have focused on understanding the properties of fuel debris (the mixture of melted nuclear fuels and structural materials), found within the damaged reactors. That debris must be carefully removed and disposed of.

However, many uncertainties remain concerning the physical and chemical state of the fuel debris and this greatly complicates retrieval efforts.

Attempts to Understand the Chemistry of Radioactive Cesium Results in a World First

A significant amount of radioactive Cs was released from the damaged Fukushima Daiichi reactors in particulate form. The particles, termed Cs-rich microparticles (CsMPs), are poorly soluble, small (< 5 µm) and have a glass-like composition.

Prof. Satoshi Utsunomiya from Kyushu University, Japan, led the current study. He explained that the CsMPs “formed in the bottom of the damaged reactors during the meltdowns, when molten nuclear fuel impacted concrete.”

After formation, many CsMPs were lost from the reactor containment into the surrounding environment.

Detailed characterization of CsMPs has revealed important clues about the mechanisms and extent of the meltdowns. However, despite abundant Cs in the microparticles, direct atomic scale imaging of radioactive Cs in the particles has proven impossible.

Prof. Gareth Law, a study collaborator from the University of Helsinki, explained that “this means we lack full information on the chemical form of Cs in the particles and fuel debris.”

Utsunomiya continued, “whilst Cs in the particles is present at reasonably high concentrations, it is often still too low for successful atomic scale imaging using advanced electron microscopy techniques. When Cs is found at a high enough concentration, we have found that the electron beam damages the sample, rendering resulting data useless”. However, in the team’s previous work using a state-of-the-art high-resolution high-angle annular dark-field scanning transmission electron microscope (HR-HAADF-STEM), they found inclusions of a mineral called pollucite (a zeolite) within CsMPs. Law explained that “in past analysis we showed that the iron-rich pollucite inclusions in the CsMPs contained >20 wt.% Cs. In nature, pollucite is generally aluminum-rich.

The pollucite in the CsMPs was clearly different to that in nature indicating it formed in the reactors.” Utsunomiya continued, “because we knew that most of the Cs in CsMPs is fission derived, we thought that analysis of the pollucite could yield the first ever direct images of radioactive Cs atoms”.

Zeolites can become amorphous when subjected to electron beam irradiation, but that damage is related to the composition of the zeolite, and the team found that some pollucite inclusions were stable in the electron beam.

Learning this and informed by modelling, the team set about pain-staking analysis that saw Utsunomiya, graduate student Kanako Miyazaki, and the team finally image radioactive Cs atoms.  

Utsunomiya explained:

“It was incredibly exciting to see the beautiful pattern of Cs atoms in the pollucite structure, where about half of the atoms in the image correspond to radioactive Cs.”

He continued: “this is first time humans have directly imaged radioactive Cs atoms in an environmental sample. Finding concentrations of radioactive Cs high enough in environmental samples that would permit direct imaging is unusual and presents safety issues. Whilst it was exciting to make a scientific world first image, at the same time it’s sad that this was only possible due to a nuclear accident.”

Scientists collected samples of contaminated soil near the damaged Fukushima Daiichi reactors.

CREDIT

Satoshi Utsunomiya

More than an Imaging Breakthrough

Utsunomiya emphasized that the study's findings are broader than mere imaging of radioactive Cs atoms: “Our work sheds light on pollucite formation and the likely heterogeneity of Cs distribution within the FDNPP reactors and the environment.”

Law further underscored relevance: “we unequivocally demonstrate a new Cs occurrence associated with the materials emitted from the FDNPP reactors. Finding Cs containing pollucite in CsMPs likely means it also remains in the damaged reactors; as such, its properties can now be considered in reactor decommissioning and waste management strategies.”

Collaborator Emeritus Prof. Bernd Grambow from Subatech, IMT Atlantique Nantes University, added that: “we should now also begin to consider the environmental behavior or Cs-pollucite and its possible impacts. It likely behaves differently to other forms of Cs fallout documented thus far. Also,the effect on human health might have to be considered. The chemical reactivity of pollucite in the environment and in body fluids is certainly different than that of other forms of deposited radioactive Cs”. Finally reflecting on the study's significance, Prof. Rod Ewing from Stanford University underscored the pressing need for continued research to inform debris removal strategies and environmental remediation: “yet again, we see that the pain-staking analytical efforts of international scientists really can unlock the mysteries of nuclear accidents, aiding long-term recovery efforts.”

The study, titled "Invisible radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant," is published in the Journal of Hazardous Materials. The work was supported by bilateral funding from the Japan Society for the Promotion of Science and the Research Council of Finland.

Citation of the Article

Title: “Invisible” radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant

Authors: Kanako Miyazaki, Masato Takehara, Kenta Minomo, Kenji Horie, Mami Takehara, Shinya Yamasaki, Takumi Saito, Toshihiko Ohnuki, Masahide Takano, Hiroyuki Shiotsu, Hajime Iwata, Gianni F. Vettese, Mirkka P. Sarparanta, Gareth, T. W. Law, Bernd Grambow, Rodney C. Ewing, and Satoshi Utsunomiya

Journal: Journal of Hazardous Materials

Link to paper (free access): https://www.sciencedirect.com/science/article/pii/S0304389424006836

DOI: 10.1016/j.jhazmat.2024.134104

Contact details

Satoshi Utsunomiya: utsunomiya.satoshi.998@m.kyushu-u.ac.jp

(Web page: http://www.scc.kyushu-u.ac.jp/ircl/utu-e/index-e.htm)

Gareth Law: gareth.law@helsinki.fi

(Web page: https://researchportal.helsinki.fi/en/persons/gareth-law)

Rod Ewing: rewing1@stanford.edu

 

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JOURNAL

Journal of Hazardous Materials

DOI

10.1016/j.jhazmat.2024.134104 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

“Invisible” radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant

 

Parasitic worm likely playing role in decline of moose populations

WASHINGTON STATE UNIVERSITY

PULLMAN, Wash. – A parasitic worm that can infest the brains of moose appears to be playing a role in the decline of the iconic animal in some regions of North America.

Moose populations have been dwindling for years across the country due to many contributing factors, but new research at Washington State University has found the impact of Eleaophora schneideri, also known as the arterial worm, has likely been underestimated.

Researchers examined recently deceased Shiras moose in Idaho between March 2020 and July 2022. While the parasitic roundworm E. schneideri was not detected in any of the animals found in north Idaho, it was present in 10 of the 20 adult moose studied in the southeastern portion of the state. Nine of the infected not only had adult worms in their major arteries but their brains were littered with microfilariae, the microscopic early life stage of the worm.

“The microfilaria are just scattered throughout their brains, and even though the damage from each is miniscule, they're basically shot-gunning the whole brain,” said Kyle Taylor, a pathologist at WSU’s Washington Animal Disease Diagnostics Laboratory. “We hypothesize the cumulative effects of large numbers of microfilariae in the brain may be associated with increased morbidity or chance of mortality, with mortality more likely in cases with larger numbers of worms.”

The research, published in the Journal of Wildlife Diseases, is part of a three-year collaborative project on moose mortality with the Idaho Fish and Game and Dr. Janet Rachlow of the University of Idaho, College of Natural Resources.

E. schneideri is primarily transmitted by tabanid flies like horse and deer flies. Mature worms can measure as long as 4.5 inches and are most commonly found in the carotid arteries in the area of the head and neck, where they will mate and release microfilariae into the bloodstream.

Infection can lead to a condition known as elaeophorosis in which the host’s circulation system is disrupted. It can advance to blindness, abnormal behavior, damage to the ears and muzzle, and death. Infections have been reported in a variety of species, including deer, domestic and wild sheep, and elk. Unlike moose, mule deer and black-tail deer are considered to be natural hosts and typically show minimal to no signs of infection.

There are currently no tests available to determine whether a live moose is infected with the parasite.

Taylor’s team examined 61 recently deceased moose in Idaho. No evidence of infection was found in northern Idaho moose or juveniles, but 10, or half, of the adult moose studied in southeastern Idaho were infected. Of those 10, three had damage to the tips of their ears, a condition attributed to E. schneideri infection. Four exhibited abnormal behavior prior to their deaths, possibly due to neuropathology associated with the parasite.

Based on their findings and that of other research, Taylor suspects the subtle but widespread damage to the brain caused by the worms may be leading to reduced fitness of the moose, which could increase risk of predation, and, sometimes, cause death. 

“We really need to have an understanding of all the issues related to moose population decline, and this parasite appears to be a factor,” Taylor said.

The study also explored the geographic spread of E. schneideri in Idaho. The parasite was found to be widespread in southeastern Idaho, aligning with its prevalence in neighboring regions of Montana and Wyoming. The distribution coincides with populations of mule deer.

Christine Haake, a pathology resident at WADDL and graduate student in the Department of Veterinary Microbiology and Pathology, helped to lead the study. Field sampling was performed and directed by Dr. Logan Weyand, who was a graduate student at the University of Idaho during the project. WADDL pathologist Chrissy Eckstrand and parasitologist Laura Williams assisted with the research.

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JOURNAL

Journal of Wildlife Diseases

DOI

10.7589/JWD-D-23-00112 

ARTICLE PUBLICATION DATE

28-May-2024

Green concrete recycling twice the coal ash is built to last

New modelling reveals that low-carbon concrete developed at RMIT University can recycle double the amount of coal ash compared to current standards, halve the amount of cement required and perform exceptionally well over time.

RMIT UNIVERSITY

 

IMAGE: 

THE RMIT TEAM: (L-R)) DR YUGUO YU, PROFESSOR SUJEEVA SETUNGE, DR DILAN ROBERT, DR CHAMILA GUNASEKARA, DR DAVID LAW. 

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CREDIT: MICHAEL QUIN, RMIT UNIVERSITY.

New modelling reveals that low-carbon concrete developed at RMIT University can recycle double the amount of coal ash compared to current standards, halve the amount of cement required and perform exceptionally well over time.

More than 1.2 billion tonnes of coal ash were produced by coal-fired power plants in 2022. In Australia, it accounts for nearly a fifth of all waste and will remain abundant for decades to come, even as we shift to renewables.

Meanwhile, cement production makes up 8% of global carbon emissions and demand for concrete – which uses cement as a key ingredient – is growing rapidly.

Addressing both challenges head-on, engineers at RMIT have partnered with AGL's Loy Yang Power Station and the Ash Development Association of Australia to substitute 80% of the cement in concrete with coal fly ash.

RMIT project lead Dr Chamila Gunasekara said this represents a significant advance as existing low-carbon concretes typically have no more than 40% of their cement replaced with fly ash.

"Our addition of nano additives to modify the concrete’s chemistry allows more fly ash to be added without compromising engineering performance,” said Gunasekara, from RMIT’s School of Engineering.

 

Finding new opportunities in overlooked pond ash

Comprehensive lab studies have shown the team’s approach is also capable of harvesting and repurposing lower grade and underutilised ‘pond ash’– taken from coal slurry storage ponds at power plants – with minimal pre-processing.

Large concrete beam prototypes have been created using both fly ash and pond ash and shown to meet Australian Standards for engineering performance and environmental requirements.

“It’s exciting that preliminary results show similar performance with lower-grade pond ash, potentially opening a whole new hugely underutilised resource for cement replacement,” Gunasekara said.

“Compared to fly ash, pond ash is underexploited in construction due to its different characteristics. There are hundreds of megatonnes of ash wastes sitting in dams around Australia, and much more globally.”

“These ash ponds risk becoming an environmental hazard, and the ability to repurpose this ash in construction materials at scale would be a massive win.”

 

New modelling technology shows low-carbon concrete’s long-term resilience

A pilot computer modelling program developed by RMIT in partnership with Hokkaido University' Dr Yogarajah Elakneswaran has now been used to forecast the time-dependent performance of these new concrete mixtures.

According to Dr Yuguo Yu, an expert in virtual computational mechanics at RMIT, a longstanding challenge in the field has been to understand how newly developed materials will stand the test of time.

“We’ve now created a physics-based model to predict how the low-carbon concrete will perform over time, which offers us opportunities to reverse engineer and optimise mixes from numerical insights,” Yu explained.

This pioneering approach – recently unveiled in the prestigious journal Cement and Concrete Research – reveals how various ingredients in the new low-carbon concrete interact over time.

“We’re able to see, for example, how the quick-setting nano additives in the mix act as a performance booster during the early stages of setting, compensating for the large amounts of slower-setting fly ash and pond ash in our mixes,” Gunasekara says.

“The inclusion of ultra-fine nano additives significantly enhances the material by increasing density and compactness.”

This modelling, with its wide applicability to various materials, marks a crucial stride towards digitally assisted simulation in infrastructure design and construction.

By leveraging this technology, the team aims to instil confidence among local councils and communities in adopting novel low-carbon concrete for various applications.

This research was enabled by the ARC Industrial Transformation Research Hub for Transformation of Reclaimed Waste Resources to Engineered Materials and Solutions for a Circular Economy (TREMS). Led by RMIT’s Professor Sujeeva Setunge, TREMS brings together top scientists, researchers and industry experts from nine Australian universities and 36 state, industry, and international partners to minimise landfill waste and repurpose reclaimed materials for construction and advanced manufacturing.

Relevant studies

‘Unified hydration model for multi-blend fly ash cementitious systems of wide-range replacement rates’ is published in Cement and Concrete Research (DOI: 10.1016/j.cemconres.2024.107487)   

‘Sulphate and acid resistance of HVFA concrete incorporating nano silica’ is published in Construction and Building Materials (DOI: 10.1016/j.conbuildmat.2023.132004) 

‘Long term mechanical performance of nano-engineered high volume fly ash concrete’ is published in Journal of Building Engineering (DOI: 10.1016/j.jobe.2021.103168) 

Dr Chamila Gunasekara holds a sample of the low-carbon concrete.

CREDIT

Michael Quin, RMIT University.

JORNAL

Cement and Concrete Research

DOI

10.1016/j.cemconres.2024.107487 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Unified hydration model for multi-blend fly ash cementitious systems of wide-range replacement rates

 

An online meeting with your dog?

Dogs can imitate human actions from two-dimensional video projections.

EÖTVÖS LORÁND UNIVERSITY

 

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OWER DEMONSTRATES THE ACTION “CROSS PAW” BY CROSSING ONE ARM OVER OTHER

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CREDIT: PHOTO CREDIT: FUMI HIGAKI

A new study just published in Biologia Futura by researchers from the Department of Ethology at Eötvös Loránd University in Budapest, Hungary, found that dogs can imitate human actions from two-dimensional video projections. The study discovered that dogs’ cognitive abilities to process and replicate actions observed in 2D video projections aligns with their everyday observational experiences with humans.

Using the Do as I Do training method, the researchers trained two dogs, Tara, a male Golden Retriever, and Franc, a female Labrador Retriever, to imitate human actions, first from live demonstrations, and then displayed on a screen. The setup involved life-size video projections streamed via online conference software, enabling real-time interaction between the dogs and their owners, who were located remotely. For example, the owner would spin in a circle in front of the camera of its device and verbally cue the dog to "Do it!". The dog, having observed this action on the screen, was then expected to replicate it.

The video abstract of the study can be found here: https://youtu.be/FvDz9UIA2wQ?si=-b64XIfDYxe3jaiT

The experiment tested the dogs’ ability to imitate actions observed from three different camera angles: frontal, side and above. The tested actions included walking backward, spinning horizontally, pushing a buzzer button and lying down, among others. Additionally, the dogs were tested on their ability to imitate novel actions, not included in the training, such as picking up an object, touching a pole with their nose, and knocking down a water bottle. The results showed that

dogs could replicate actions observed from frontal and side angles, which are observational perspectives commonly encountered in dogs’ daily lives with humans.

However, they faced challenges when trying to imitate actions from an overhead perspective, which is a less familiar viewpoint.

“Using the Do as I Do imitation paradigm is similar to asking the dogs, ‘What did I just do?’ while showing them on the screen various human actions under different camera angles. The dogs responded by performing matching actions based on how they perceived and processed the demonstration. For instance, one of the demonstrated actions included knocking down a plastic bottle, which was demonstrated from an overhead view. My dog Tara observed my demonstration on the screen, looked for the bottle in his room, in front of the screen, and then knocked it down. But he struggled to replicate other actions with an overhead view.” explained Fumi Higaki, coauthor and owner of Tara.

“This study, even if only exploratory, not only advances our understanding of how dogs perceive and interpret human actions, but more importantly, this innovative method could broaden research into several other potential cognitive abilities, and could also be extended to other species,” said lead researcher, Claudia Fugazza.

The Do as I Do training method has been employed to study imitative abilities not only of dogs but also of cats, orcas, and various other species. If you are intrigued by this training approach, you can explore it further in the recently published second edition of the author's book, now available from Dogwise. It's a valuable resource for dog lovers worldwide!

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JOURNAL

Biologia Futura

DOI

10.1007/s42977-024-00222-6 

ARTICLE TITLE

Exploring the use of projected videos to test action matchingfrom different perspectives in dogs

 

Final dust settles slowly in the deep sea

\

ROYAL NETHERLANDS INSTITUTE FOR SEA RESEARCH

 

IMAGE: 

DEPLOYMENT OF ROYAL IHC’S APOLLO II PRE-PROTOTYPE NODULE COLLECTOR VEHICLE FROM THE AFT OF RV SARMIENTO DE GAMBOA DURING THE 2018 FIELD TEST IN MÁLAGA BIGHT.

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CREDIT: PHOTO COURTESY: ALBERTO SERRANO.

'Dust clouds' at the bottom of the deep sea, that will be created by deep-sea mining activities, descend at a short distance for the biggest part. That is shown by PhD research of NIOZ marine geologist Sabine Haalboom, on the bottom of the Pacific Ocean. Yet, a small portion of the stirred-up bottom material remains visible in the water at long distances. "These waters are normally crystal clear, so deep-sea mining could indeed have a major impact on deep-sea life," Haalboom states in her dissertation that she defends at Utrecht University on May 31st.

Unidentified Living Organisms between manganese nodules

Currently, the international community is still discussing the possibilities and conditions for mining valuable metals from the bottom of the deep sea. This so-called deep-sea mining may take place at depths where very little is known about underwater life. Among other things, the silt at the bottom of the deep sea, which will be stirred up when extracting manganese nodules, for example, is a major concern. Since life in the deep sea is largely unknown, clouding the water will definitely create completely unknown effects.

Variety of instruments

For her research, Haalboom conducted experiments with different instruments to measure the amount and also the size of suspended particles in the water. At the bottom of the Clarion Clipperton Zone, a vast area in the depths of the Pacific Ocean, Haalboom performed measurements with those instruments before and after a grid with 500 kilograms of steel chains had been dragged across the bottom.

Still murky for a long time

"The first thing that strikes you when you take measurements in that area, is how unimaginably clear the water naturally is," Haalboom says. "After we dragged the chains back and forth over a 500-meter stretch, the vast majority of the stirred-up material settled within just a few hundred meters. Yet, we also saw that a small portion of the stirred-up bottom material was still visible up to hundreds of meters from the test site and meters above the bottom. The water was a lot murkier than normal at long distances from the test site."

In a follow-up study, in which PhD candidate Haalboom was not involved, the ‘dust clouds’ were visible even up to five kilometers away from the test site.

Scarce food in clear water

International companies that are competing for concessions to extract the scarce metals from the deep-sea floor, are seizing on the results of these initial trials as an indication of the low impact of deep-sea mining on bottom life. Yet, that is not justifiable, says the co-promoter of Haalboom's research, NIOZ oceanographer Henko de Stigter. "Sure, based on this PhD research and also based on follow-up research, we know that the vast majority of the dust settles quickly. But when you take in consideration how clear these waters normally are, and that deep-sea life depends on the very scarce food in the water, that last little bit could have a big impact."

Too early to decide

Both Haalboom and De Stigter urge more research before firm statements can be made about the impact of deep-sea mining. "It is really too soon to say at this point how harmful or how harmless that last bit of dust is that can be spread over such great distances", De Stigter emphasizes.

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DOI

10.33540/2217 

 

Transformation and mechanisms of climate wet/dry change on the northern Tibetan Plateau under global warming: A perspective from paleoclimatology

SCIENCE CHINA PRESS

 

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(A) COMPARISON OF WET/DRY BETWEEN THE MEDIEVAL CLIMATE ANOMALY AND THE LITTLE ICE AGE; (B) DIFFERENCES IN WET/DRY BETWEEN THE MEDIEVAL CLIMATE ANOMALY AND THE LITTLE ICE AGE; (C) WET/DRY CHANGES IN THE MID-HOLOCENE; (D) DIFFERENCES IN DRYNESS AND WETNESS BETWEEN THE MID-HOLOCENE AND THE PRE-INDUSTRIAL REVOLUTION.

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CREDIT: ©SCIENCE CHINA PRESS

Historical patterns of climate change can provide ways to predict future climate change. During geological history, the earth has experienced many warm periods of different time scales, such as the mid-Holocene warm period, the medieval climate anomaly, etc. The northern margin of the Tibetan Plateau are located at the intersection of the Asian summer monsoon and mid-latitude westerly circulation. It is regional climate change has the unique complexity of the monsoon-westerly transition zone and is sensitive to climate change. The northern margin of the Tibetan Plateau is a typical area for studying climate change and its mechanisms.

Recently, based on paleo-environmental records, paleoclimate simulations and modern observations, the team of Professor Yu Li of Lanzhou University compared the wet/dry changes of the Middle Holocene (MH) warm period, the medieval climate anomaly (MCA), the modern warm period and the warm period in the next hundred years in the northern margin of the Tibetan Plateau, and discussed the climate change law and mechanism in this region. They evaluated wet/dry change patterns at the northern edge of the Tibetan Plateau under future global warming scenarios through paleoclimate similarities. Paper "Transformation and Mechanisms of Climate Wet/Dry Change on the Northern Tibetan Plateau under Global Warming: A Perspective from Paleoclimatology, "published in Science China Earth Sciences.

The study found that the climate during the mid-Holocene warm period on the northern edge of the Tibetan Plateau was warm and humid. The enhanced summer monsoon driven by the orbital scale led to increased precipitation. The high-altitude westerly winds in winter strengthened but had little impact on the regional climate. During the medieval climate anomaly, the climate at the northern edge of the Tibetan Plateau was warm and dry, the summer monsoon weakened, and the southward-moving high-altitude westerly winds brought a small amount of precipitation in winter. Increased solar radiation led to increased evaporation, which affected regional wet/dry changes.

During the modern warm period, evaporation decreased significantly, precipitation continued to increase, and the climate on the northern edge of the Tibetan Plateau showed an obvious trend of warming and humidification. In the warm period of the next hundred years, as greenhouse gas concentrations rise, the impact of temperature on regional wet/dry changes will intensify. Continued warming will lead to the expansion of the westerly belt and a gradually humid climate. In the future, the wet/dry changes on the northern edge of the Tibetan Plateau will be more similar to those in the mid-Holocene warm period.

Climate change is generally cyclical, and wet/dry changes in historical warm periods can provide a historical background for predicting future wet/dry changes. Referring to the climate characteristics of the mid-Holocene warm period on a millennium scale, the northern edge of the plateau will experience multiple cold and warm events before the climate reaches stability in the future. The wet/dry pattern on a long time scale is still mainly controlled by the strength and influence range of the monsoon, as well as the interaction with the westerly circulation.

 

Wet/Dry pattern of the northern edge of the Tibetan Plateau in the next hundred years 

(a)P−E distribution under SSP2-4.5 scenarios from 2025 to 2100; (b) Temperature distribution under SSP2-4.5 scenarios from 2025 to 2100; (c) Wind field distribution in summer (June, July, August) under SSP2-4.5 scenario from 2025 to 2100; (d) Wind field distribution in winter (December, January , February) under the SSP2-4.5 scenario from 2025 to 2100.

CREDIT

©Science China Press

Li Y, Zhang Z, Zhou X, Gao M, Duan J, Xue Y, Shang H, Liu S. 2024. Transformation and mechanisms of climate wet/dry change on the northern Tibetan Plateau under global warming: A perspective from paleoclimatology. Science China Earth Sciences, 67, https://doi.org/10.1007/s11430-023-1260-6

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JOURNAL

Science China Earth Sciences

DOI

10.1007/s11430-023-1260-6