Ph.D. Geography, 1989
Director, National Snow and Ice Data Center (NSIDC)
Professor, Dept. of Geography
- Arctic climate variability and change
- High latitude atmospheric circulation
- Numerical weather prediction in high latitudes
- Arctic atmosphere-ocean-ice interactions
- The hydrologic cycle
Current Research: Understanding the environmental impacts of a changing Arctic
As the Arctic loses its summer sea ice cover, the region becomes more accessible to marine transport, tourism, and extraction of energy resources. As the economic and strategic importance of the Arctic grows, so does the need to better understand its climate and weather patterns, and to communicate the implications of Arctic change to the public. Research during the past year has been guided by these principles. My group’s work continued to elucidate processes leading to “Arctic amplification,” the observed outsized rise in temperatures in the Arctic relative to the rest of the globe.
While sea ice loss is a primary driver of Arctic amplification, a number of other processes appear to contribute, including changes in cloud cover and atmospheric heat transport into the region. It has been argued by some scientists that Arctic amplification is having influences on mid-latitude weather patterns in autumn and winter. While there is evidence of such impacts from modeling studies, observational evidence is, at best, conflicting. In the coming year, in collaboration with other CIRES scientists from both modeling and observational frameworks, we will examine in detail responses to Arctic amplification both within the Arctic and at middle-latitudes.
A new line of research started during the past year focused on better understanding the characteristics, variability, and environmental impacts of the Summer Arctic Frontal Zone and how this seasonal feature may change in the future. Most prior research work concludes that the Arctic Frontal Zone develops in response to summer heating contrasts between the Arctic Ocean and snow-free land. Areas where the frontal zone is best expressed are regions of frequent cyclogenesis (storm formation). It appears that these cyclones have significant impacts on summer precipitation not only along the Arctic coast, but also over the central Arctic Ocean, which is where many of the storms eventually migrate. Another major accomplishment of the past year was the completion of the second edition of my textbook with Roger Barry, titled “The Arctic Climate System.” As has been the case for the past seven years, I participated in field work in the Alaskan Arctic to monitor snow-cover conditions.