Some 20,000 musk oxen died on Canada's far-northern Banks Island because of such conditions during the winter several years ago. Yet, their deaths went unnoticed until the next spring. The new satellite-detection method could provide an early warning to native people, giving them a realistic chance of getting food to herds to prevent mass starvation.
"We are talking about Banks Island, but this applies to the whole Arctic - Alaska, northern Canada, Siberia, Scandinavia - wherever there is permafrost," says Jaakko Putkonen of the University of Washington in Seattle, who participated in the satellite study.
Banks Island is at the edge of the Beaufort Sea inside the Arctic Circle. In October 2003, rain fell for several days there on top of a 6-inch snow cover. The rain seeped through the snow to the soil surface. The temperature then plunged, and the water became a thick layer of ice that lasted the winter. It prevented browsing animals from reaching their food supply of lichens and mosses at the soil's surface.
"Starvation happened over a period of many months, and no one knew until they went up to do the population count the next spring," says the University of Washington's Thomas Grenfell, who traced satellite clues of the Banks Island event with Putkonen.
Rain falling on snow can mean lingering death for musk oxen, reindeer, and other animals that root through the snow to graze on the Arctic tundra. Grenfell and Putkonen found evidence for the 2003 rain-on-snow occurrence in passive satellite microwave imagery, which they believe could provide a signature to help detect such events anywhere.
In the new study, the scientists examined data from 10 different satellite microwave channels, each providing slightly different information on the qualities of the snowpack. "The subtleties in the microwave levels mean there can be high error margins on this information, but the Banks Island event stood out like a sore thumb," Grenfell says.
He and Putkonen detail their work in a paper now in press with Water Resources Research, a journal of the American Geophysical Union.
Grenfell has conducted more than 40 field experiments in polar regions and has become quite familiar with precipitation characteristics there. Much of the previous work he did was with researchers who were interested in the nature of the snowpack, but he found that the presence of water interfered with interpreting satellite microwave readings. For the new research, the signal from water was key, he says.
The researchers hope to search other satellite microwave records for evidence of rain-on-snow events of the last 30 years that are known from anecdotal information.
The 2003 rain-on-snow event affected the northern part of the 43,000-square-mile Banks Island. The musk oxen population of 70,000 was cut by nearly 30 percent, but a caribou herd on the southern part of the island was unaffected. The closest weather station, about 60 miles from the musk oxen range, didn't record any rainfall at the time of the event that resulted in the massive die off, so few people recognized that the oxen were in distress.
Currently, there is no way to know exactly where or how often these potentially devastating rain-on-snow events occur, the researchers say, but using satellite data to locate them could make up for a scarcity of weather stations in the sparsely populated Arctic.
Rain-on-snow events historically have occurred mostly in coastal areas. However, in earlier research, Putkonen found that models predict that climate change will push winter rainfall much farther into northern continents and large islands.
While food shortages can trigger a large die off, there also can be severe consequences from milder events that force animals to exert more energy to get food. That reduces body weight and limits reproduction, which in turn can cause long-term damage to herds.
Peter Weiss | American Geophysical Union
Receding glaciers in Bolivia leave communities at risk
20.10.2016 | European Geosciences Union
UM researchers study vast carbon residue of ocean life
19.10.2016 | University of Miami Rosenstiel School of Marine & Atmospheric Science
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences