Precipitation Mechanisms over Complex Terrain

大气中三种主要的降水云系是深对流、锋面系统和热带气旋。 这个项目研究了山脉的存在如何影响每一个。 这项研究将分析现有的数据集，包括过去几次国家科学基金会资助的实地活动的数据集。智力优势：通过识别关键成分，可以理解和预测复杂地形地区的强降水和洪水。 这项研究确定了与三种主要风暴类型中的每一种相关的这些成分。 深对流的成分将通过比较喜马拉雅山、安第斯山脉、台湾中部山脉和墨西哥西马德雷西方上空的暴雨对流的行为来检查和识别。这些不同的地点提供了各种天气和地形背景，以便通过比较这些不同地区的风暴来确定强降雨和洪水的重要因素。 母体天气条件的范围从斜压波倾斜赤道在亚洲，季风条件，赤道波，和日强迫。 将对不列颠哥伦比亚省的沿海山区进行研究，以检验切变和热诱导湍流增强迎风面降水的假设。 将通过检查飓风卡尔（2005年）和热带风暴多莉（2014年）进入并穿越墨西哥马德雷山脉东方时的情况，研究热带气旋通过山区的相关因素。 地形锁定重力波和触发对流的作用将被检查为修改和延长热带气旋眼墙和雨带的降水的成分。 通过研究主要大气降水系统在经过山区时对降水的这些类型的增强作用，并确定关键因素，该项目将有助于更全面地了解山区对降水云的影响。 此外，通过更好地了解山脉如何影响风暴，未来的研究可能会更好地预测自然灾害发生的模式如何在不断变化的气候中改变。 此外，该项目还将优化利用以往实地活动的数据集，并将有助于培训妇女和少数民族从事大气科学研究。

The three major types of precipitating cloud systems in the atmosphere are deep convection, frontal systems, and tropical cyclones. This project examines how each is affected by the presence of mountains. The research will analyze existing datasets including those of several past National Science Foundation funded field campaigns.Intellectual Merit:Heavy precipitation and flooding in regions of complex terrain can be understood and anticipated by identifying key ingredients. This research identifies such ingredients associated with each of the three principal storm types. The ingredients for deep convection will be examined and identified by comparing behavior of heavy rain-producing convection over the Himalayas, Andes, Central Mountains of Taiwan, and the Sierra Madre Occidental of Mexico. These different venues provide a variety of synoptic and orographic settings so that the important ingredients for intense rainfall and flooding will be identified through comparison of the storms in these different regions. The parental synoptic conditions range from baroclinic waves dipping equatorward over Asia, to monsoonal conditions, to equatorial waves, and diurnal forcings. The ingredients for enhancement of precipitation when fronts cross mountain ranges will be examined for the coastal mountains of British Columbia to test the hypothesis that shear and thermally-induced turbulence enhance windward side precipitation. The ingredients associated with the passage of tropical cyclones over mountains will be studied by examining Hurricane Karl (2005) and Tropical Storm Dolly (2014) as they entered and crossed the Sierra Madre Oriental of Mexico. The roles of terrain-locked gravity waves and triggering of convection over the mountains will be examined as ingredients for modifying and prolonging the precipitation in the eyewalls and rainbands of tropical cyclones. Through studying these types of enhancement of precipitation by the major atmospheric precipitation systems as they pass over mountains and identifying key ingredients, this project will contribute to a more general understanding of the effects of mountains on precipitating clouds.Broader Impacts:This work will have the broader impact of laying groundwork for improved forecasting of heavy precipitation in regions of the earth most prone to flooding and disastrous societal impacts. Further, by better understanding how mountains affect storms, future studies may better anticipate how the patterns of occurrence of natural disasters might be altered in a changing climate. In addition, this project will optimize the use of past field campaign datasets and will contribute to training women and minorities for atmospheric sciences research.