Synoptic Modulation of the Antarctic Surface Wind Regime

*9725263教区这个项目研究从南极大陆冰盖下流下来的寒冷和强烈的地面风(所谓的katabatic风)如何与南极周围天气系统通过所产生的更大规模的气压梯度相互作用。最近的研究表明，虽然赤道风在南部高纬度地区的大气质量、热量和动量收支中起着重要的作用，但它们与天气系统的相互作用是复杂和不清楚的，不同的研究得出了不同的结论。这项研究将利用对南极对流层结构的一系列观测，这些观测是1994年和1995年为若干规定的观察期收集最完整、最详细和最准确的数据集的国际努力所产生的，这是对流层区域观测研究(Frost)的第一次。最先进的数值模型将补充这些观察结果：国家大气研究中心/宾夕法尼亚州立大学MM5模型、科罗拉多州立大学RAMS模型和威斯康星大学NMS模型。初步工作表明，这些模式将能够现实地解决南极环境问题。将对东南极洲沿岸的气旋系统进行数值模拟，以解决赤道风场的响应问题。将对模型结果进行广泛的评估，以确定运动方程中受天气系统、赤道风和下伏地形影响的各个项的大小。预计这项工作将提供新的信息，更好地了解南极天气系统与高纬度和低纬度自由大气环流以及全球大气过程之间的联系。***

*** 9725263 Parish This project is a study of how the cold and intense surface winds that flow down from the antarctic continental ice sheet (the so-called katabatic winds) interact with the larger scale pressure gradients that result from the passage of synoptic weather systems around the antarctic perimeter. Recent research has shown that while katabatic winds play an important role in the atmospheric mass, heat, and momentum budgets at high southern latitudes, their interaction with synoptic weather systems is complex and unclear, with different studies leading to different conclusions. This study will make use of a series of observations on the structure of the antarctic troposphere that resulted from an international effort to assemble the most complete, detailed, and accurate data set possible for several prescribed observation periods in 1994 and 1995 - the First Regional Observing Study of the Troposphere (FROST). State-of-the-art numerical models will complement these observations: the National Center for Atmospheric Research/Pennsylvania State University MM5 model, the Colorado State University RAMS model, and the University of Wisconsin NMS model. Preliminary work has indicated that these models will be capable of realistically resolving the antarctic environment. Numerical simulations of cyclonic systems along the coast of East Antarctica will be conducted to resolve the response of the katabatic wind regime. Extensive evaluation of model results will take place in order to determine the magnitude of individual terms in the equations of motion that are affected by the synoptic systems, the katabatic winds, and the underlying terrain. It is expected that this work will provide new information and a greater understanding of the connections of antarctic weather systems to the circulation of the free atmosphere both at higher altitudes and lower latitudes, and to global atmospheric processes. ***