Climate change may complicate avalanche risk across the Pacific Northwest

University of Washington

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

A cross-section of snowpack reveals a thin, darker ice layer running horizontally through the snow. Ice layers like this one form when rain falls onto snow and freezes, forming a crust. This creates a boundary within the snowpack that can cause snow to slip and trigger an avalanche. New research from the University of Washington shows that as the climate warms, more parts of the Pacific Northwest will likely see increased avalanche risks due to these icy crusts.

view more 

Credit: Clinton Alden

This winter was one of the warmest on record across the West; as a result, many snowy, alpine areas have seen bouts of winter rainfall where there would ordinarily only be snow. These unusual weather patterns have contributed to an abysmal ski season, but they can also set the stage for dangerous avalanches. At temperatures close to freezing, precipitation can fall as rain but freeze when it hits the snow, forming an icy crust. Snow that accumulates on top of that crust is unstable and prone to abrupt slides, causing an avalanche that can close down a major highway in moments, endanger backcountry skiers and more.

Avalanche experts in Western Washington know how to manage the risks associated with rain-on-snow events, but many of their counterparts in colder regions like Eastern Washington, Idaho and Montana are less familiar with these dynamics. New research from the University of Washington shows that as winters in these regions warm, their snowpacks may come to resemble those of maritime areas, with more rain-on-snow events, icy crusts and complex avalanche forecasting. 

The findings were published February 25 in ARC Geophysical Research.

“This winter’s warmth is a harbinger,” said lead author Clinton Alden, a UW graduate student of civil and environmental engineering. “We know that temperatures will keep rising, and our work is a red flag for cooler regions of the greater Pacific Northwest, such as Idaho and Western Montana, that aren’t used to dealing with ice crusts and their resulting avalanche problems.”

The study is part of a larger effort to understand the structure of snow as it accumulates, which has implications for weather and avalanche forecasting, wildlife dynamics and more. 

“Snow scientists are pretty good at measuring snow depth and volume,” said senior author Jessica Lundquist, a UW professor of civil and environmental engineering. “We’re also pretty good at figuring out how much water you get if all that snow melts. But our models aren’t as good at representing snow structure, such as layers of different densities and crystal types that increase avalanche risks. And we really want to know how the structure of snow changes as the climate changes. That’s a tricky question that no one has tackled, particularly for rain-on-snow conditions.”

To dig into that question, the researchers studied how warming influences ice layer formation in seasonal snowpacks. First, they collected temperature and precipitation data captured by 53 monitoring stations across the Pacific Northwest for the past 25 years. They used a computer model to identify days when ice layers likely formed at each location. They then checked the model against real-world measurements at one of the locations — a station at Snoqualmie Pass — and found that the model matched the measurements with 74% accuracy.

Finally, they used the same model to simulate those same 25 winters at 2 C and 4 C warmer than they were, and looked for changes to the number of ice crusts across the region. According to the UW Climate Impacts Group, the Pacific Northwest is expected to warm by 2 C to 5 C by 2050 as compared to pre-2000 temperatures.

The results were split regionally by the Cascade mountains. In colder, inland parts of the Pacific Northwest — places like Eastern Washington, Idaho and Montana — higher temperatures created more rain-on-snow days and more avalanche-prone ice layers. Locations in the warmer, maritime Cascades saw the opposite effect: Higher temperatures created slush instead of ice, potentially reducing the avalanche risk associated with ice crusts. 

The predicted snowpack changes may also impact wildlife behavior. Some foraging mammals, such as reindeer, dig down into the snow in search of food and may have a hard time breaking through an icy crust. Conversely, firm ice might provide a better running surface for animals fleeing predators. Specific regional effects will require additional study.

What’s clear now is that those who work or play in avalanche terrain in broad swaths of the Pacific Northwest — and even beyond — may need to adjust to a new set of risk factors.

“I get calls from avalanche forecasters in places like Colorado, Wyoming and Montana. They tell me they’re getting rain at 10,000 feet, which they’ve never seen before,” said co-author John Stimberis, the avalanche forecaster supervisor at Washington State Department of Transportation at Snoqualmie Pass, who earned his master’s in transportation and highway engineering at the UW. “They want to know when to expect the onset of avalanches and when to expect the return to stability.” 

Alden hopes that this research will encourage further collaboration within the avalanche forecasting community.

“I’d love to see this shared with avalanche forecasters widely, both as a call to action and as a way to help them understand what their snowpack might look like in the future,” Alden said.

Benjamin K. Sullender, the director of geospatial science at Audubon Alaska and former doctoral student of environmental and forest sciences at the UW, is a co-author.

This research was funded by the NASA Interdisciplinary Research in Earth Science program and the UW Program on Climate Change’s Graubard Fellowship.

For more information, contact Alden at cdalden@uw.edu.

This map shows the change in number of “ice crust days” across the 53 monitoring sites during the simulated winter with 2 C warming. The Cascade sites overwhelmingly saw fewer theoretical ice crust days, whereas cooler inland regions overwhelmingly saw more.

Credit

Alden et. al/ARC Geophysical Research

Journal

ARC Geophysical Research

DOI

10.5149/ARC-GR.2451 

Article Title

Higher Temperatures Lead to More Melt-Freeze Crusts in Snowpacks in Cooler Regions of the Pacific Northwest

 

NASA’s EDGE mission taps Boise State as part of next-generation Earth observation effort

Boise State researchers are part of the team behind the Earth Dynamics Geodetic Explorer, or EDGE, a satellite mission concept aimed at monitoring Earth’s land, ice and coastal regions that NASA selected to launch as early as 2030.

Boise State University

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Example LiDAR (Light Detection and Ranging) data “point cloud” showing vegetation and surface topography. The data is colored by elevation (left, in rainbow), reflectivity “brightness” of the received laser pulse (middle, gray), and surface type such as vegetation, ground and water (right).

view more 

Credit: Josh Enterkine, Boise State University research associate in Boise State’s geosciences department

EDGE is one of two next-generation satellite missions announced in February. The mission will help NASA better understand changes to the Earth’s surface and will create detailed 3D maps of vegetation, as well as ice formations like glaciers and sea ice. It builds on the work of two existing NASA satellites, but will do it better and more precisely.

This is particularly important for ecosystems in the semi-arid west, where measuring low-height vegetation such as shrubs and vegetation on steep slopes is challenging. Accurate measurement of vegetation in these landscapes is critical for applications including fire management, grazing and recreation. Information that the mission generates will help improve capabilities for assessing pre-fire risk and evaluating post-fire impacts.

Helen Amanda Fricker at UC San Diego will head the mission. Joining Fricker is Boise State’s Nancy Glenn, vice president of research and economic development and professor of geosciences. 

“Our faculty and students are doing exceptional work to better understand Earth’s systems, and this mission creates new opportunities for collaboration across the university and beyond,” Glenn said. “Participation in a NASA mission of this scale highlights the growing impact of Boise State as a research university.”

Josh Enterkine, research associate in Boise State’s geosciences department, also sees the value of this project.

“The EDGE mission’s global imaging capability will allow Boise State teams to bridge critical gaps between small-scale drone and ground-based surveys and existing satellite datasets,” Enterkine said. “This will help translate fine-scale environmental patterns into broader regional and global insights on wildfires and water systems,.”

Boise State researchers use Light Detection and Ranging, or LiDAR, data across a wide range of studies — from mapping bird habitats and modeling post-wildfire debris flows in Idaho, to assessing vegetation and carbon storage in forests and rangelands.  The data generated through EDGE will support research in these areas, enabling Boise State researchers to advance important work that benefits both the region and the nation. 

In a press release issued by NASA, Nicky Fox, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington, stated, “NASA uses the unique vantage point of space to study our home planet to deliver life-saving data into the hands of disaster response and decision-makers every day for the benefit of all, while also informing future exploration across our solar system. By understanding Earth’s surface topography, ecosystems and atmosphere, while also enabling longer range weather forecasting, these missions will help us better study the extreme environments beyond our home planet to ensure the safety of astronauts and spacecraft as we return to the Moon with the Artemis campaign and journey onward to Mars and beyond.”

The EDGE project has been selected for continued development as part of NASA’s Earth System Explorers Program, which conducts principal investigator-led Earth science missions based on key priorities laid out by the science community and national needs. 

The selected missions will advance to the next phase of development, and each mission will be subject to confirmation review in 2027. This review will assess the missions’ progress and the availability of funds. If confirmed, the total estimated cost of each mission, not including launch, will not exceed $355 million, with a mission launch date of no earlier than 2030.

For more information about the Earth System Explorers Program, visit their webpage.

Study: New system aims to detect percentage of recycled plastic in plastic products

University at Buffalo researchers want to provide regulators and others a quick and reliable way to assess sustainability claims

University at Buffalo

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

BUFFALO, N.Y. – Recycled plastics are promoted on everything from water bottles and fleece jackets to shopping bags and yogurt cups. Verifying such claims, however, is another matter because there is no quick and reliable way to measure how much recycled plastic these products contain.

University at Buffalo researchers are addressing this problem by combining several scientific tests, as well as artificial intelligence, to create a new method for differentiating recycled plastic from new plastic.

Described in a study published today in Nature's Communications Engineering, the method aims to help companies, regulatory agencies and other organizations better monitor plastic recycling.

“Our goal is to create a quick and reliable tool that can be used to verify recycled material content, as well as enforce recycling regulations,” says corresponding author Amit Goyal, PhD, SUNY Distinguished Professor and SUNY Empire Innovation Professor in the UB Department of Chemical and Biological Engineering.

The tool, he says, aims to “improve the quality of plastic products and help reduce plastic waste, which will support a more circular economy where plastic pollution and its associated health and environmental risks are reduced.”

Why it’s difficult to tell recycled plastic from new plastic

When plastic is recycled, it is melted, cleaned and remolded. The end product looks just like new plastic and it has a very similar chemical makeup. But there are subtle differences, such as microscopic impurities and broken polymer chains, found in recycled plastics.

To spot these differences, the research team employed four sensing techniques. They are:

·         Triboelectric testing. This measures how plastic gains and holds an electrical charge when surfaces touch – in other words, static electricity. Recycled plastics often hold a charge longer due to structural defects from repeated processing.

·         Dielectric/impedance spectroscopy. This technique applies an electric field to measure how a plastic stores and loses energy. Recycled plastics show lower energy storage and higher energy loss.

·         Capacitance analysis. This tracks how quickly plastic charges and discharges in a circuit. Differences in timing can reveal changes in electrical properties caused by recycling plastic.

·         Mid-infrared spectroscopy. This shines light on the chemical structure of plastics, and it can show fragmented polymer chains found in recycled plastic.

Machine learning analyzes data, predicts recycled content

Researchers tested the method by examining new and recycled PET, or polyethylene terephthalate, which is a common plastic used to make juice bottles, peanut butter jars and other goods.

To analyze and combine data from these tests, the researchers utilized machine learning, which is a type of AI. Their machine learning model studied the test results and learned to recognize patterns in the data that correlate with recycled plastic percentages.

The system was more than 97% effective at determining the percentage of recycled content in PET samples that contained anywhere from 0% to 50% recycled material.

"This is an ideal example of combining cutting-edge innovation in science and engineering with AI for social good, and to potentially realize significant societal impact," said Goyal.

Team's future work aims to create a portable device

Goyal says the team’s future work will involve combining the method's different sensing techniques and machine learning model into a portable device.

“By fabricating such a device, we hope to enable widespread, real-time monitoring of recycled plastics in commercial products,” he says.

The work’s relevance will grow, he says, as more states and countries adopt regulations that require plastics to be made with some recycled materials. Such regulations are expected in the near future given ongoing work of the Intergovernmental Negotiating Committee – a United Nations-led initiative – to finalize an international legally binding agreement to end plastic pollution.

The New York State Center for Plastics Recycling Research and Innovation at UB provided funding for the research. The center is supported by a grant from New York State Environmental Protection Fund, administered by the New York State Department of Environmental Conservation. 

---

Journal

Communications Engineering

DOI

10.1038/s44172-026-00639-y 

Article Title

Determining the percentage of recycled plastic content in a plastic product

Article Publication Date

23-Mar-2026

 

Bee dancing is better with the right audience

Precision of the food-directional ‘waggle dance’ fluctuates with audience size and who’s in attendance

University of California - San Diego

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

A dancing honey bee (center) is surrounded by an audience of “followers” that carefully interpret the movements of the ultra-fast ‘waggle’ dance.

view more 

Credit: Heather Broccard Bell

Dance like nobody’s watching? Not quite, at least not for honey bees.

In recent years, scientists have carefully deciphered details of the honey bee “waggle dance,” which is an advanced form of social communication in the animal kingdom. University of California San Diego biologists and their international colleagues recently unraveled how the dance conveys critical information about food sources for the benefit of fellow hive inhabitants.

A new study on the dynamics of the dance, published in the Proceedings of the National Academy of Sciences, finds that it’s not just the dance performer that matters — it’s also who’s in the audience. The experiments showed that the performing forager is not simply broadcasting a predetermined message. Rather, the precision of the performer’s directions to the food source depends on its audience.

Once a foraging bee returns to the hive after discovering a promising food source, it communicates this vital location information to hive mates by performing a blazing-fast, complex dance. While nestmates pay attention, the dancing forager runs forward while “waggling” its abdomen, then loops back and repeats the performance in a matter of seconds. The angle of the waggle dance conveys the direction of the food relative to the sun, and the duration of the performance encodes the distance to the source.

Professor James Nieh of the UC San Diego School of Biological Sciences likens the new findings to a street performance. With a good-sized audience, street musicians focus on the performance itself. But when the crowd thins, the performer scans faces, shifts position and puts more effort into finding and keeping an audience. The search for a receptive audience essentially changes the bee's performance because it is difficult to maintain the precision of a fast, repeated movement pattern while simultaneously moving around to locate and engage an audience.

“Everyone has seen a street musician or a performer adjust to a changing crowd,” said Nieh, a faculty member in the Department of Ecology, Behavior and Evolution. “In the hive, we see a comparable tradeoff. When fewer bees follow, dancers move more as they search for their audience, and the dance becomes less precise.”

Working with scientists at the Chinese Academy of Sciences and Queen Mary University of London, Nieh studied experimental hives and monitored the honey bee “dance floor,” which replicated the crowded, dynamic social space found in real hives. In the first part of the experiment, they evaluated fluctuating numbers of bees in the primary dancing area to test the changes caused by different audience sizes. In a second set of experiments, they held the number of bees constant, but changed the age of the audience members by introducing young worker bees, which are not interested in following dances. In both experimental scenarios, dancers were less precise when performing for a smaller audience.

“The waggle dance is often presented as a one-way information transfer,” said Ken Tan, the senior author of the study and a researcher at the Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences. “Our data show that feedback from the audience shapes the signal itself. In that sense, the dancer is not only sending information, but also responding to social conditions on the dance floor.”

The new study also provided clues to how dancers sense audience size and composition. Audience members, they found, make frequent antennal and body contact with dancers. Such tactile cues likely provide information about audience composition.

Lars Chittka, a researcher at Queen Mary University of London, said the study shows that “humans aren’t the only ones who perform differently depending on their audience. Our study shows that honey bees quite literally dance better when they know someone is watching. When followers are scarce, dancers wander around searching for listeners — and in doing so, their signals become fuzzier. It’s a lovely reminder that even in the miniature world of insects, communication is a deeply social affair.”

Apart from honey bees, the new research results offer a window into how animal groups manage information. Collective groups of animals often depend on signals that must be repeated, shared and acted upon.

“The new findings show that the accuracy of a signal can depend on the availability of receivers, not only on the motivation of the sender,” said Nieh. “That kind of feedback may be important in animal societies, engineered swarms and other distributed systems where the quality of information can rise or fall with audience dynamics.”

The study’s researchers include: Tao Lin, Shihao Dong, Gaoying Gu, Fu Zhang, Xiuchuan Ye, Tianyi Wang, Ziqi Wang, Jianjun Li, James C. Nieh, Lars Chittka and Ken Tan.

Funding for the study was provided by the 14th Five-Year Plan of Xishuangbanna Tropical Botanical Garden; Chinese Academy of Sciences (E3ZKFF3B); the Yunnan Revitalization Talents Support Plan (XDYC-QNRC-2023-0566); and National Natural Science Foundation of China (32571753 and 32322051).

When honey bee foragers locate a food source, such as this lemonade berry sumac shrub (Rhus integrifolia), they return to the hive and communicate the source through the intricate details of the waggle dance. Credit: Heather Broccard Bell

---

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2518687123 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

The audience shapes the information content of the honey bee waggle dance

Article Publication Date

23-Mar-2026

Bumblebees Are Hosts For Dangerous Bee Virus

Red-tailed bumblebees can act as hosts for a dangerous bee virus. CREDIT: Uni Halle / Patrycja Pluta

 March 25, 2026  

By Eurasia Review

Wild bumblebees serve as key hosts for acute bee paralysis virus. While the virus appears to cause little harm to bumblebees, infection is usually fatal to honeybees. Until now, it was assumed that honeybees were the key host for the virus. By using data from extensive field trials, a team from Martin Luther University Halle-Wittenberg (MLU) and Georg August University of Göttingen has now identified the red-tailed bumblebee as the key host for acute bee paralysis virus. Their study was published in the journal “Ecology Letters” and could help inform policies that aim at curbing the spread of such diseases in nature.

Honeybees, wild bees and other insect species are connected by their shared visits to flowers. “A flowering summer meadow is therefore both a source of food and a potential site for the transmission of viral infections. This is because insects searching for food there come into contact with material that may be contaminated with viruses, such as pollen and nectar,” says biologist Professor Robert Paxton from MLU. Until now, research has assumed that honeybees serve as primary hosts for various viruses and can thus infect bumblebees and other wild bees. However, the new study paints a different picture: according to it, wild bees can also be reservoir hosts for viruses and thus theoretically contribute to the infection of honeybees.

This result is based on field data collected by the team at 32 locations in Lower Saxony and Hesse. The researchers first observed whether different bee species visit the same flower species. They also used virus screening of 1,725 insects comprising multiple bee species to analyse how much each bee species contributes to the spread of various viruses. “To identify the bee species that contribute the most to the spread of viruses, we used the basic reproduction number, R?. This measure estimates how widely a virus can spread from one insect to others of the same species,” explains Patrycja Pluta from MLU, lead author of the study. The team calculated precisely for each combination of virus and bee species how easily a virus can spread and how much each bee species potentially contributes to the spread of viruses.

The researchers identified the most important host insects for three known bee viruses. They found that honeybees are the main carriers of deformed wing virus (DWV) and black queen cell virus (BQCV) at the sites studied. „However, the main host insect for the acute bee paralysis virus is a wild bee: the red-tailed bumblebee Bombus lapidarius,” says Patrycja Pluta. When honeybees become infected with the virus, they are unable to fly after a short time, start to tremble and die within a few days. This can lead to the rapid collapse of an entire colony.

Another finding: the composition of bee species at a location has less influence on the spread of viruses than previously assumed. In contrast, direct contact with bees that transmit many viruses plays a decisive role. And this occurs when visiting flowers. According to Robert Paxton, these findings are important for understanding how diseases spread in nature and how they can possibly be counteracted. „The more space and the more diverse food bees have, the less likely infections are to occur. To minimise the risk of further spread of disease, more flower strips with many different plant species would be very helpful, for example,“ says Paxton.