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

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。这项工作将记录西伯利亚地区观测到的水文气候学变化，将这些变化归因于气候变化背景下的特定物理机制，并研究这些变化从区域到半球天气和气候的影响。该项目将利用观测分析和模拟实验来调查北极海冰趋势与季节性积雪变化之间的联系。秋季积雪特别令人感兴趣，因为尽管有强劲的变暖趋势及其与平流层-对流层耦合和随后冬季半球变率的关系，但其在过去二十年中持续增加，而秋季积雪一直在增加，春季积雪一直在减少。这项工作将从水汽输送、天气活动和土壤湿度的变化方面探索与海冰的联系，从平流层-对流层耦合事件的时间和发生的变化方面探索与大尺度大气动力学的联系。这将有可能更好地评价与积雪和大气有关的反馈机制，并应导致对北极未来趋势的定量评估。冰雪覆盖对未来全球温度趋势可能产生的影响凸显了对北极地区区域地表-大气水和能量交换动态形成基本认识的重要性。观测数据将包括遥感和台站观测（CPC/Rutgers University的积雪覆盖范围、雪深、俄罗斯水文气象网络的湿度和温度数据，以及校正后的降水）以及NCEP/NCAR和ECMWF再分析的数据。这项工作应有助于增进对北极气候反馈机制的了解，了解它们与观测到的过去和模拟的未来趋势的关系，以及它们对半球尺度上天气和气候的影响。

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.