Collaborative Research: Critical Issues on Cold Region Precipitation Characteristics

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The type of precipitation to reach the earth's surface is highly dependent on the lower tropospheric temperature profile. Strong and persistent temperature inversions, a unique vertical profile over the Arctic during the cold season, pose unique challenges to the determination of precipitation type. In other regions, surface air temperature can be used as a predictor of this condition, but this measurement cannot be used in high-latitude locales. This collaborative research project will address some critical issues associated with precipitation type in order to better understand the spatial and temporal patterns of changes in the frequency of different precipitation types associated with increasing air temperatures over pan-Arctic land areas. The investigators will identify the atmospheric and other environmental conditions associated with each precipitation type specifically for high-latitude regions. They will use historical station records across Arctic land regions to compile the frequencies of each precipitation characteristic using various statistical analyses and mapping tools. They will analyze these data in order to enhance the capabilities for climate and hydrological model simulations of snow conditions to assess potential changes in the hydrological cycle and energy budgets. The investigators also plan to examine how much variability in precipitation type is related to short-term fluctuations in major atmospheric circulation patterns as opposed to background long-term warming trends.Project results are expected to enhance basic knowledge regarding how precipitation characteristics change in response to changing atmospheric conditions. The project should contribute to enhancement of fundamental theory regarding the determination of precipitation types based on atmospheric and environmental conditions unique to the Arctic region. Because climate change has been most evident over the Arctic due to the high sensitivity of snow and ice to the energy budget, the project should provide valuable information that is especially critical to interdisciplinary research on the Arctic ecosystem, species dynamics, and human-nature interactions. The project also will aid in efforts to determine the possible future nature of climatic change in the Arctic and to assess the viability of different strategies for adapting to changing conditions. This project is jointly supported by the Geography and Spatial Sciences Program, the Arctic System Science Program, and the Climate and Large-Scale Dynamics Program.