Thursday, January 02, 2025

 

Artificial intelligence: Algorithms improve medical image analysis



Algorithms based on deep learning can detect tumors - KIT researchers among the best teams at the International AutoPET Competition


Karlsruher Institut für Technologie (KIT)

Automated methods enable the analysis of PET/CT scans (left) to accurately predict tumor location and size (right). 

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Automated methods enable the analysis of PET/CT scans (left) to accurately predict tumor location and size (right) for improved diagnosis and treatment planning.

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Credit: Gatidis S, Kuestner T. (2022) A whole-body FDG-PET/CT dataset with manually annotated tumor lesions (FDG-PET-CT-Lesions) [Dataset]. The Cancer Imaging Archive. DOI: 10.7937/gkr0-xv29




Imaging techniques play a key role in the diagnosis of cancer. Precisely determining the location, size, and type of tumors is essential for choosing the right therapy. The most important imaging techniques include positron emission tomography (PET) and computer tomography (CT). PET uses radionuclides to visualize metabolic processes in the body. The metabolic rate of malign tumors is considerably higher than that of benign tissues. Radioactively labeled glucose, usually fluorine-18-deoxyglucose (FDG), is used for this purpose. In CT, the body is scanned layer by layer in an X-ray tube to visualize the anatomy and localize tumors.

 

Automation Can Save Time and Improve Evaluation

Cancer patients sometimes have hundreds of lesions, i.e. pathological changes caused by the growth of tumors. To obtain a uniform picture, it is necessary to capture all lesions. Doctors determine the size of the tumor lesions by manually marking 2D slice images – an extremely time-consuming task. “Automated evaluation using an algorithm would save an enormous amount of time and improve the results,” explains Professor Rainer Stiefelhagen, Head of the Computer Vision for Human-Computer Interaction Lab (cv:hci) at KIT.

 

Rainer Stiefelhagen and Zdravko Marinov, a doctoral student at cv:hci, took part in the international autoPET competition in 2022 and came in fifth out of 27 teams involving 359 participants from all over the world. The Karlsruhe researchers formed a team with Professor Jens Kleesiek and Lars Heiliger from the Essen-based IKIM – Institute for Artificial Intelligence in Medicine. Organized by the Tübingen University Hospital and the LMU Hospital Munich, autoPET combined imaging and machine learning. The task was to automatically segment metabolically active tumor lesions visualized on a whole-body PET/CT. For the algorithm training, the participating teams had access to a large annotated PET/CT dataset. All algorithms submitted for the final phase of the competition are based on deep learning methods. This is a variant of machine learning that uses multi-layered artificial neural networks to recognize complex patterns and correlations in large amounts of data. The seven best teams from the autoPET competition have now reported on the possibilities of automated analysis of medical image data in the Nature Machine Intelligence journal.

 

Algorithm Ensemble Excels in the Detection Tumor Lesions

As the researchers explain in their publication, an ensemble of the top-rated algorithms proved to be superior to individual algorithms. The ensemble of algorithms is able to detect tumor lesions efficiently and precisely. “While the performance of the algorithms in image data evaluation partly depends indeed on the quantity and quality of the data, the algorithm design is another crucial factor, for example with regard to the decisions made in the post-processing of the predicted segmentation,” explains Stiefelhagen. Further research is needed to improve the algorithms and make them more resistant to external influences so that they can be used in everyday clinical practice. The aim is to fully automate the analysis of medical PET and CT image data in the near future. (or)

 

Original publication

Sergios Gatidis, Marcel Früh, Matthias P. Fabritius, Sijing Gu, Konstantin Nikolaou, Christian La Fougère, Jin Ye, Junjun He, Yige Peng, Lei Bi, Jun Ma, Bo Wang, Jia Zhang, Yukun Huang, Lars Heiliger, Zdravko Marinov, Rainer Stiefelhagen, Jan Egger, Jens Kleesiek, Ludovic Sibille, Lei Xiang, Simone Bendazzoli, Mehdi Astaraki, Michael Ingrisch, Clemens C. Cyran & Thomas Küstner: Results from the autoPET challenge on fully automated lesion segmentation in oncologic PET/CT imaging. Nature Machine Intelligence, 2024. DOI: 10.1038/s42256-024-00912-9

 

More about the cv:hci of KIT

Balancing renewable energy expansion and biodiversity conservation: new study highlights overlap of solar energy potential and critical habitats in the Southwest



PeerJ




As the climate crisis accelerates, the urgent transition to renewable energy sources is at the forefront of global sustainability efforts. However, a new study by Ms. Kylee Fleckenstein, published in PeerJ Life & Environment, reveals a critical challenge in balancing renewable energy development with biodiversity conservation inthe arid Southwest United States.

The research, titled "Mapping species of greatestconservation need and solar energy potential in thearid Southwest for future sustainable development", explores the intersection of high-priority conservationhabitats and areas suitable for large-scale Solar EnergyDevelopment (SED). With its abundant sunshine andopen landscapes, the Southwest boasts some of thehighest Global Horizontal Irradiance (GHI) values in thecountry, making it a prime location for solar energyexpansion. However, the region is also home to unique and vulnerable species, including the LeConte’s Thrasher (Toxostoma lecontei), Bendire’s Thrasher (Toxostoma bendirei), Sonoran Desert Tortoise (Gopherus morafkai), Mojave Desert Tortoise (Gopherus agassizii), and the Southwestern population of the Burrowing Owl (Athene cunicularia).

Ms. Fleckenstein’s study uses a novel combined approach, employing species distribution modeling (SDM) to map areas of likely species presence and high habitat suitability, alongside a site suitability analysis for potential solar development sites. The findings indicate a significant overlap between high-priority habitats and optimal locations for SED, underscoring the urgent need for strategies that balance renewable energy growth with conservation priorities.

“Our study highlights a paradox: the same landscapes that make the Southwest ideal for solar energydevelopment are also critical for the survival of speciesthat are already facing threats from habitat loss, population growth, and climate change,” said Ms. Fleckenstein. “This research offers a roadmap foridentifying areas where development can proceed sustainably, minimizing impacts on biodiversity.”

The study provides actionable insights forpolicymakers, conservationists, and developers, emphasizing the importance of integrating biodiversity conservation into renewable energy planning. By identifying areas of overlap between conservationpriorities and energy potential, stakeholders can make informed decisions to support both sustainabledevelopment and the protection of the region’s unique ecological heritage.

As the U.S. prepares to scale up renewable energyinitiatives, particularly solar energy projects, the study calls for a collaborative approach to ensure that renewable energy solutions do not come at the cost ofirreplaceable biodiversity.

Key Findings:

  • Significant overlap exists between optimal solardevelopment locations and critical habitats forseveral vulnerable species.
  • Species distribution modeling (SDM) and site suitability analysis offer effective tools foraligning energy development with conservationpriorities.
  • A coordinated, science-based approach is crucial for mitigating the impacts of solar energyprojects on sensitive ecosystems.

This research serves as a call to action for a balanced approach to climate solutions, ensuring that the shift to renewable energy is not only sustainable but also responsible.

 

Bringing the magic of playing music to the virtual world



University of Birmingham
The Joint Active Music Sessions (JAMS) platform uses avatars created by individual musicians and shared with fellow musicians to create virtual concerts, practice sessions, or enhance music teaching. 

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A musician records themselves and sends the video to another musician.  The software creates a responsive avatar that plays in perfect synchrony with the music partner.  All you need is an iPhone and a VR headset to bring musicians together for performance, practice, or teaching.

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Credit: ARME project




Researchers are aiming to bring the magic of playing music in person to the virtual world. 

The Joint Active Music Sessions (JAMS) platform, created at the University of Birmingham, uses avatars created by individual musicians and shared with fellow musicians to create virtual concerts, practice sessions, or enhance music teaching. 

Dr Massimiliano (Max) Di Luca from the University of Birmingham explains: “A musician records themselves and sends the video to another musician.  The software creates a responsive avatar that plays in perfect synchrony with the music partner.  All you need is an iPhone and a VR headset to bring musicians together for performance, practice, or teaching.”  

The JAMS platform has the potential to develop a social network like Spotify or Myspace, where musicians can interact to learn, connect, perform, develop new music, and create virtual concerts that reach larger audiences. 

JAMS has the distinct flavour of a platform developed with and for musicians whether successful or at an early stage of learning.  

The avatars capture the unspoken moments that are key in musical performance, allowing practice partners or performers to watch the tip of the violinist’s bow, or make eye contact at critical points in the piece.  They also have real-time adaptability and are dynamically responsive to the musician on the VR headset, so delivering a unique, personalised experience.

Delivery by VR headset recreates the musician’s world and provides an immersive backdrop with a realistic rendering of other musicians and cues used in the real-life setting.  It also keeps the faces at eye level, which adds to the feeling of connectedness.  

Critically, there is no ‘latency’ in the JAMS user experience.  Dr Di Luca explains: “Latency is the delay between a sound production and when it reaches the listener, and performers can start to feel the effects of latency as low as 10 milliseconds, throwing them ‘off-beat’, breaking their concentration, or distracting them from the technical aspects of playing.”

JAMS is underpinned by an algorithm created during the Augmented Reality Music Ensemble (ARME) project, that captures dynamic timing adjustments between performers.  The project brought together researchers from six disciplines (psychology, computer science, engineering, music, sport science, and maths), whose input realised the vision of building a computational model that reproduces, with precision, a musician’s body movements and delivers an avatar that meets the needs co-performers.

“We’re aiming to bring the magic of playing music in person to the virtual world.  You can adapt the avatar that other people play with, or learn to play better through practice with a maestro.”

JAMS allows musicians to perform in an interactive virtual group, and can be adapted for lipsyncing or dubbing in media.  It can also gather unique user data to create digital twins of musicians, offering licensing opportunities for various applications, and further exploitation of catalogues and publishing rights.  

Commercial enquiries should be directed to the ARME project website at: https://arme-project.co.uk/contact/

 

Big leap forward for environmentally friendly ‘e-textiles’ technology



University of Southampton
Testing the e-textile sensing 

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UWE PhD student Marzia Dulal testing the e-textile sensing properties.

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Credit: Marzia Dulal





A research team led by the University of Southampton and UWE Bristol  has shown wearable electronic textiles (e-textiles) can be both sustainable and biodegradable.

A new study, which also involved the universities of Exeter, Cambridge, Leeds and Bath, describes and tests a new sustainable approach for fully inkjet-printed, eco-friendly e-textiles named ‘Smart, Wearable, and Eco-friendly Electronic Textiles’, or ‘SWEET’.

Findings are published in the journal Energy and Environmental Materials.

E-textiles are those with embedded electrical components, such as sensors, batteries or lights. They might be used in fashion, for performance sportwear, or for medical purposes as garments that monitor people’s vital signs.

Such textiles need to be durable, safe to wear and comfortable, but also, in an industry which is increasingly concerned with clothing waste, they need to be kind to the environment when no longer required.

Professor Nazmul Karim at the University of Southampton’s Winchester School of Art,  who led the study, explains: “Integrating electrical components into conventional textiles complicates the recycling of the material because it often contains metals, such as silver, that don’t easily biodegrade. Our potential ecofriendly approach for selecting sustainable materials and manufacturing overcomes this, enabling the fabric to decompose when it is disposed of.”

The team’s design has three layers, a sensing layer, a layer to interface with the sensors and a base fabric. It uses a textile called Tencel for the base, which is made from renewable wood and is biodegradable. The active electronics in the design are made from graphene, along with a polymer called PEDOT: PSS. These conductive materials are precision inkjet-printed onto the fabric.

The researchers tested samples of the material for continuous monitoring of human physiology using five volunteers. Swatches of the fabric, connected to monitoring equipment, were attached to gloves worn by the participants. Results confirmed the material can effectively and reliably measure both heart rate and temperature at the industry standard level.

Dr Shaila Afroj, an Associate Professor of Sustainable Materials from the University of Exeter and a co-author of the study, highlighted the importance of this performance: “Achieving reliable, industry-standard monitoring with eco-friendly materials is a significant milestone. It demonstrates that sustainability doesn’t have to come at the cost of functionality, especially in critical applications like healthcare.”

The project team then buried the e-textiles in soil to measure its biodegradable properties. After four months, the fabric had lost 48 percent of its weight and 98 percent of its strength, suggesting relatively rapid and also effective decomposition. Furthermore, a life cycle assessment revealed the graphene-based electrodes had up to 40 times less impact on the environment than standard electrodes.

Marzia Dulal from UWE Bristol, a Commonwealth PhD Scholar and the first author of the study, highlighted the environmental impact: “Our life cycle analysis shows that graphene-based e-textiles have a fraction of the environmental footprint compared to traditional electronics. This makes them a more responsible choice for industries looking to reduce their ecological impact.”

The ink-jet printing process is also a more sustainable approach for e-textile fabrications, depositing exact numbers of functional materials on textiles as needed, with almost no material waste and less use of water and energy than conventional screen printing.

Professor Karim concludes: “ Amid rising pollution from landfill sites, our study helps to address a lack of research in the area of biodegradation of e-textiles. These materials will become increasingly more important in our lives, particularly in the area of healthcare, so it’s really important we consider how to make them more eco-friendly, both in their manufacturing and disposal.”

The researchers hope they can now move forward with designing wearable garments made from SWEET for potential use in the healthcare sector, particularly in the area of early detection and prevention of heart-related diseases that 640 million people (source: BHF) suffer from worldwide.

Ends

Notes to Editors
 

  1. The study Sustainable, Wearable, and Eco-Friendly Electronic Textiles is published in the journal Energy and Environmental Materials, DOI: 10.1002/eem2.12854 and can be viewed here: https://onlinelibrary.wiley.com/doi/full/10.1002/eem2.12854
     
  2. For interviews contact Peter Franklin, Media Relations, University of Southampton. press@soton.ac.uk +44 23 8059 3212
     
  3. Images and a short video relating to the project, for download, can be found here: https://safesend.soton.ac.uk/pickup?claimID=zcENEKmxubFBFHsY&claimPasscode=DHkPdKPHYHSZZNWq&emailAddr=206376
     
  4. Partners on this project include, the University of Southampton, UWE Bristol, University of Bath, University of Leeds, University of Exeter and University of Cambridge.
     
  5. For more about the University of Southampton’s Winchester School of Art visit: https://www.southampton.ac.uk/about/faculties-schools-departments/winchester-school-of-art
     
  6. The University of Southampton drives original thinking, turns knowledge into action and impact, and creates solutions to the world’s challenges. We are among the top 100 institutions globally (QS World University Rankings 2025). Our academics are leaders in their fields, forging links with high-profile international businesses and organisations, and inspiring a 22,000-strong community of exceptional students, from over 135 countries worldwide. Through our high-quality education, the University helps students on a journey of discovery to realise their potential and join our global network of over 200,000 alumni. www.southampton.ac.uk


Material decomposition (IMAGE)

University of Southampton


Demonstrating testing swatches of e-textile material to monitor heart rate.

 

NIH officials assess threat of H5N1


Balancing enhanced vigilance and “business as usual”




NIH/National Institute of Allergy and Infectious Diseases

Wild bird and H5N1 virus particles 

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Photo of a wild bird. To the right is a colorized transmission electron micrograph of H5N1 virus particles (purple). H5N1 bird flu is widespread in wild birds worldwide, and in 2024 is causing a multistate outbreak in poultry and U.S. dairy cows. Bird photo by NIAID; micrograph, which has been repositioned and recolored by NIAID, is courtesy CDC. 

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Credit: NIAID and CDC




WHAT:
Highly pathogenic H5N1 avian influenza A virus (HPAI H5N1) remains a low risk to the general public, and public health experts in the United States believe that available treatments and vaccines, as well as those in development, are sufficient to prevent severe disease. However, the National Institutes of Health (NIH) and its federal partners remain focused on monitoring the virus and evaluating changes, according to leading officials at the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH. 

In a commentary published in the New England Journal of Medicine, NIAID Director Jeanne M. Marrazzo, M.D., M.P.H., and Michael G. Ison, M.D., M.S., chief of the Respiratory Diseases Branch in NIAID’s Division of Microbiology and Infectious Diseases, say people should find a balance between enhanced vigilance and “business as usual” with respect to HPAI H5N1.

Since 1996, HPAI H5N1 influenza viruses have circulated in at least 23 countries. In late 2021, HPAI H5N1 spread from Europe to North America causing sporadic infections among wild birds and poultry farms. In 2022, the virus spread to South America where it devastated birds and marine mammals. In March 2024, USDA scientists identified HPAI H5N1 in U.S. dairy cows, and it subsequently reached herds in 16 states. The virus has been detected in dairy herds in three states over the past 30 days, according to USDA/APHIS. In 2024, the virus has caused 66 confirmed and 7 probable cases of influenza in people in the U.S. and one case in Canada. These human cases have been caused by either the H5N1 type circulating in birds (D1.1) or the type circulating in dairy cows (B3.13).

Against this backdrop, Drs. Marrazzo and Ison say there are four keys to controlling the current outbreak. The first imperative is timely, effective collaborations among investigators in human and veterinary medicine, public health, health care, and occupational workers, such as dairy and poultry workers.

This involves cultivating trust not only between numerous entities, but with people seeking care for symptoms of concern, including conjunctivitis, the authors write. Fortunately, so far most U.S. cases of HPAI H5N1 have been mild and resolved on their own without the need for treatment.

Their second key is a focus on the Canadian HPAI H5N1 patient, who developed respiratory failure and required life-saving medical intervention and treatment before recovering. The authors write that mutations found in the virus in this patient highlight an urgent need for vigilant disease surveillance to identify and assess viral changes to evaluate the risk for person-to-person transmission. Effective surveillance, they say, requires that complete genomic sequencing data from animals and people are made rapidly and readily available.

Without information pertaining to where and when isolates were collected, the data cannot be linked phylogenetically to other reported sequences, limiting insight into how the virus is spreading, they write. These data would also provide opportunity for early detection of mutations that might portend avidity for human respiratory epithelium, which may require as little as one mutation in the virus.

Third, researchers must continue to develop and test medical countermeasures—such as vaccines and therapies that eliminate or alleviate disease—against H5N1 and other influenza viruses. Fortunately, current vaccine candidates neutralize the circulating strains, which so far are susceptible to antivirals that could mitigate transmission and severity of illness, they write.

Lastly, Drs. Marrazzo and Ison encourage people to take precautions to prevent exposure to the virus and minimize the risk of infection. For example, people who work with poultry and cows should use personal protective equipment and educate themselves about occupational risks when working with birds and mammals, as CDC and USDA have repeatedly recommended.

Ideally, following these four steps will help scientists and public health officials investigating HPAI H5N1 to answer the many remaining questions more quickly about how the virus is spreading, evolving, and affecting people, other mammals, and birds.

ARTICLE:
M Ison and J Marrazzo. The Emerging Threat of H5N1 to Human Health. NEJM DOI: 10.1056/NEJMe2416323 (2024).

WHO:
NIAID Director Jeanne M. Marrazzo, M.D., M.P.H., and Michael G. Ison, M.D., M.S., chief of the Respiratory Diseases Branch in NIAID’s Division of Microbiology and Infectious Diseases, are available for comment. 

CONTACT:
To schedule interviews, please contact Ken Pekoc, (301) 402-1663, kpekoc@niaid.nih.gov.


NIAID conducts and supports research—at NIH, throughout the United States, and worldwide—to study the causes of infectious and immune-mediated diseases, and to develop better means of preventing, diagnosing and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID website.
  
About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit http://www.nih.gov/.

NIH...Turning Discovery Into Health®

 

Study finds physical activity reduces chronic disease risk



Researchers recommend health care providers survey patients on physical activity levels



University of Iowa

Lucas Carr 

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Lucas Carr, University of Iowa

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Credit: University of Iowa




University of Iowa researchers are recommending all patients be surveyed about their physical activity levels, after a new study underscores the link between physical activity and chronic disease.

The study, led by Lucas Carr, associate professor in the Department of Health and Human Physiology, examined responses from more than 7,000 patients at University of Iowa Health Care Medical Center who noted their level of physical activity in a questionnaire. 

From patients’ answers to the questionnaire, the researchers found that those who reported the highest level of physical activity — meaning they exercised moderately to vigorously at least 150 minutes per week — were at statistically significant lower risk of having 19 chronic conditions, including cardiovascular disease, cancer, respiratory disease, and diabetes.

The findings further suggest patients who are least active — meaning they reported little to no exercise in a given week — are at increased risk to develop a chronic disease.

Based on those results, the Iowa researchers also recommend health care systems provide information on health and wellness services for physically inactive patients who are at most risk.

“In our health care environment, there's no easy pathway for a doctor to be reimbursed for helping patients become more physically active,” says Carr, the study’s corresponding author. “And so, for these patients, many of whom report insufficient activity, we need options to easily connect them with supportive services like exercise prescriptions and/or community health specialists.”

Most hospitals in the United States do not ask patients about their physical activity, and no hospital system in the Midwest has done so, according to the researchers. In this study, Carr partnered with Britt Marcussen, a family medicine physician in UI Health Care, to offer the questionnaire to patients visiting for annual wellness exam appointments. The study period was from November 2017 to December 2022.

The Exercise Vital Sign survey, as the questionnaire is called, asked patients two questions that they answered on a tablet:

  • “On average, how many days per week do you engage in moderate to vigorous exercise (like a brisk walk)?” (0-7 days) 
  • “On average, how many minutes do you engage in exercise at this level?” 

Carr and his team propose making the survey available to all patients.

“This two-question survey typically takes fewer than 30 seconds for a patient to complete, so it doesn’t interfere with their visit. But it can tell us a whole lot about that patient’s overall health,” Carr says.

The researchers also compared results from patients who completed the surveys with more than 33,000 patients who weren’t offered the survey in other areas of the hospital. The researchers found patients who took the survey were younger and in better health than the patient population who weren’t given the questionnaire, based on analyzing all patients’ electronic medical records. 

While the link between physical activity and reduced risk of chronic disease has been known, the researchers say the study underscores the value of surveying patients about their physical activity levels.

“We believe this finding is a result of those patients who take the time to come in for annual wellness exams also are taking more time to engage in healthy behaviors, such as being physically active,” Carr says.

In a related study, published this month in the Journal of Physical Activity and Health, Carr’s team found that when healthcare providers billed for providing exercise counseling to patients, those invoices were reimbursed by insurance providers nearly 95 percent of the time. 

“Our findings suggest the recommended physical activity billing codes are reimbursed at a high rate when providers submit them for reimbursement, which reinforces the idea to make physical activity surveys and counseling services available,” Carr says.

Cole Chapman, assistant professor in the College of Pharmacy, is the first author on the study. Chapman, who joined the Pharmacy faculty in 2019 after earning bachelor’s and doctoral degrees at Iowa, collected and analyzed the data from the patients’ electronic medical records. 

Marcussen and Mary Schroeder, associate professor in the Department of Pharmacy Practice and Science in the College of Pharmacy, are study co-authors.

The study, “Screening Patients for Physical Inactivity Helps Identify Patients at Risk for Cardiometabolic and Chronic Diseases,” was published online [INSERT ONLINE PUB DATE HERE] in Preventing Chronic Disease, a journal of the U.S. Centers for Disease Control and Prevention.

UI Health Care Stead Family Children’s Hospital funded the research.

 

Unraveling climate change-induced compound low-solar-low-wind extremes in China




Science China Press
Spatial distribution of historical compound low-solar-low-wind (LSLW) extremes. 

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In the top-left panel, the spatial distribution of compound LSLW extremes is shown, with frequency indicated by color and intensity by shading for the historical period (1961-1990). The top-right panel presents the schematic diagram of physical processes for interdiurnal correlation. East Asia is mainly influenced by two weather systems, namely the western Pacific subtropical high (WPSH) and the Mongolian-Siberian high (MSH). In low latitudes, the westward extension of WPSH induces suppressed activity in situ, resulting in predominantly clear and calm conditions. Meanwhile, prevailing southerly winds in the west flank of the WPSH transport moisture from the tropics to East Asia, leading to cloudy (low solar) and windy (high wind) conditions. In mid-high latitudes, cold front invades East Asia under the northerly wind of MSH accompanied cloudy (low solar) and windy (high wind) weather conditions. While in mountainous regions, such as Qinghai-Tibet Plateau and Hengduan Shan, local obstructive effects lead to decreasing wind speed (low wind) and uplift topography with decreasing temperature leads to cloudy conditions (low solar). The bottom-left panel shows the spatial distribution of interdiurnal correlation between wind and solar resource. The bottom-right panel displays the likelihood multiplication factor of our estimated co-occurrences of compound LSLW extremes relative to the counterfactual cases assuming low-solar and low-wind events are independent.

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Credit: ©Science China Press




This study, led by Dr. Yue Qin and Dr. Tong Zhu from the College of Environmental Sciences and Engineering at Peking University, represents one of the first comprehensive efforts to analyze the spatiotemporal patterns and drivers of compound low-solar-low-wind (LSLW) extremes across China. By coupling multi-model climate simulations with state-of-the-art statistical and diagnostic analyses, the research provides crucial insights into this emerging challenge.

“Our results suggest that under compound LSLW extremes, renewable energy generation could be significantly compromised,” said Dr. Yue Qin, one of the corresponding authors. “Even more concerning, climate change could intensify the frequency of such events, escalating threats to China’s renewable energy supply and potentially hindering progress toward carbon neutrality.”

China has pledged to achieve carbon neutrality by 2060, necessitating a profound transition toward solar and wind energy. Unlike fossil fuels, solar and wind power depend heavily on fluctuating meteorological conditions, making them inherently variable and intermittent, which poses significant risks to the stability of electricity supply.

While individual renewable energy resources have been widely studied, much less is known about the compounded challenges posed by simultaneous low solar and wind energy availability. Despite increasing recognition of compound events—such as drought-heatwave or wind-precipitation extremes—and their impacts, the vulnerability of renewable energy systems to these compound events remains understudied, particularly in China, a global leader in wind and solar energy investments.

The study highlights a strong topographic dependence in the frequency of compound LSLW extremes, with a national average frequency of 16.4 days per year (10th-90th percentile range: 5.3–32.6 days per year). Renewable energy supply in eastern China is particularly affected, with power output during these extremes dropping by ~80% compared to average climate conditions. The researchers also projected changes in compound LSLW extremes under future climate scenarios. They found that the frequency of such events increases nationwide across all scenarios, with the Tibetan Plateau and northwestern China facing high LSLW frequency and projected to experience significant frequency increases.

“In particular, a striking increase of compound LSLW extremes’ frequency occurs under SSP370 scenario with aerosol emissions increase due to the assumption of a lenient air quality policy.” said Licheng Wang, the lead author from Peking University. “It is noteworthy that the distinct increase in aerosol loading under SSP370 scenario, likely plays an important role in driving the most striking increases in compound LSLW extremes’ frequency observed nationwide. The high aerosol loading weakens wind speed by inducing a more stable boundary layer and attenuates radiation by absorbing and scattering incoming solar radiation.”

The researchers also test the inter-grid electricity transmission as an adaptation strategy, and find that it can significantly reduce the potential impacts caused by both the frequency (by over 91%), and the intensity of compound extremes indicating the extent of LSLW power output failures (by 59%-85%) of compound LSLW extremes. Notably, Xizang often demonstrates the largest potential in mitigating LSLW-induced renewable power shortages for other regions via grid interconnection. However, current interregional electricity transmission infrastructure is largely insufficient in Xizang, due to both geographical and economic challenges in developing (ultra-) high-voltage electricity transmission. Therefore, advancing renewable energy infrastructure project in Xizang could potentially play an important role in supporting China’s carbon neutrality targets.

Without a robust understanding of China’s compound LSLW extremes, renewable energy investment and power sector planning could be inadequately informed, jeopardizing China’s pursuit of carbon neutrality—a critical component of global carbon mitigation efforts.

“By revealing the geospatial and temporal evolution of compound LSLW extremes and their underlying physical mechanisms under climate change, our study emphasizes that these events are not random but predictable,” added Dr. Yue Qin. “This underscores the importance of proactive preparation and mitigation to address this pressing challenge.”

###

See the article:

Unraveling climate change-induced compound low-solar-low-wind extremes in China

https://doi.org/10.1093/nsr/nwae424