Collaborative Research: Analysis and attribution of changes in Siberian hydroclimate and implications for the future

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This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This work will document observed changes in the hydroclimatology of the Siberian region, attribute these changes to specific physical mechanisms in the context of climate change, and study the impact of those changes from the regional to the hemispheric weather and climate. The project will use observational analysis and modeling experiments to investigate the links between arctic sea ice trends and changes to seasonal snow cover. The autumn snow cover is of particular interest due to its persistent increases over the last two decades despite the robust warming trend and its connection to stratosphere-troposphere coupling and hemispheric variability in the subsequent winter season and that while fall snow cover has been increasing, spring snow cover has been decreasing. This work will explore the links to sea ice in terms of changes to moisture transport, synoptic activity, and soil moisture and the links to the large scale atmospheric dynamics in terms of changes to the timing and occurrence of stratosphere-troposphere coupling events. This will make it possible to evaluate better the feedback mechanisms associated with snow cover and the atmosphere, and should lead to a quantitative assessment of future trends in the Arctic. The likely influence of snow and ice cover on future global temperature trends highlights the importance of developing a fundamental understanding of regional surface-atmosphere water and energy exchange dynamics of the arctic regions. Observed data will include both remote sensing and station observations (snow cover extent of CPC/Rutgers University, snow depth, humidity and temperature data from the Russian Hydrometeorological network, and corrected precipitation) and data from NCEP/NCAR and ECMWF reanalyses. This work should result in an improved understanding of arctic climate feedback mechanisms, their association with observed past and modeled future trends, and their influence on weather and climate on a hemispheric scale.