A University of Wisconsin scientist presented his study on climate change and snow coverage at the American Geophysical Union fall conference in San Francisco last week. The study could help scientists learn more about climate change in the Arctic as carbon dioxide pollution continues to grow in the atmosphere.
Steven Vavrus, an associate scientist at the UW Center for Climatic Research, said the study was the first of its kind to assess the global impact of snow coverage.
"I went to the conference to share my research and learn about other related studies being done across the United States," Vavrus said.
Vavrus's main finding showed that when air temperature warmed up, the insulating effect of snow caused the ground temperature to decrease.
"When the air temperature warmed, the permafrost expanded instead of shrank," he said. "This is a counterintuitive finding because the results suggest that the insulating effect of snow coverage is more important than air change in this study."
Vavrus said he used a computer climate model to suppress all the snow coverage globally to figure out how much the snow had impacted present-day climate.
"The future climate increase of the impact of snow removal would be very sizeable and represents one-third of the climate change due to the doubling of carbon dioxide," Vavrus said. "My main goal is to remove snow regionally."
Jonathan Martin, chair of UW's atmospheric and oceanic sciences department, commented on the difference between daily weather and climate change.
"Climate is a long term average of day-to-day weather," Martin said. "Day-to-day weather is more variable while the climate is more stable and Vavrus' research is concerned with the climate."
Vavrus collaborated with three scientists from the University of Illinois who were studying cold air outbreaks. Their research found that extreme cold air outbreaks would disappear without snow coverage.
"Without snow coverage in Wisconsin, we would not get as many cold waves within the winter," Vavrus said. "It is not clear if it is the local effect creating these cold air masses or it would not be as cold because artic air masses come down from Canada, making the Wisconsin air so much colder."
Vavrus has done previous research analyzing ice coverage on lakes and climate change. He also has studied the polar climate and has primarily focused on the Artic.
"The Artic is supposed to see the largest climate change in the reduction of snow and ice coverage," Vavrus said. "This research is important because anything that will help us understand the changing of the Artic is worth pursuing."
This study could contribute to climatic research because it provides an understanding of the role of snow coverage and climate. Scientists expect the climate to warm and this study gives the upper end impact of snow cover removal.
"I want to continue with this study and try to separate the local from the remote impact of snow coverage by conducting more simulations in more detail," Vavrus said. "I am very excited to continue this study in more detail because it is the first 'big picture' look at the effect of global snow coverage on climate change."
