Precipitation Mechanisms over Complex Terrain

大气中的三种主要降水云系是深对流、锋面系统和热带气旋。这个项目考察了每一个都是如何受到山脉的影响的。这项研究将分析现有的数据集，包括过去几个国家科学基金资助的实地活动的数据集。智力上的优点：可以通过确定关键因素来了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都相关的这些成分。通过比较喜马拉雅山脉、安第斯山脉、台湾中部山脉和墨西哥西部马德雷山脉的暴雨对流行为，将检查和识别深层对流的成分。这些不同的地点提供了不同的天气和地形环境，以便通过比较这些不同地区的风暴来确定造成强降雨和洪水的重要因素。从亚洲上空向赤道方向倾斜的斜压波，到季风条件，再到赤道波和昼夜强迫，这些都是主要的天气条件。我们将针对不列颠哥伦比亚省沿海山区检验锋面越过山脉时降水增强的因素，以检验切变和热致湍流增强迎风侧降水的假说。热带气旋翻越山脉的相关因素将通过研究飓风卡尔(2005年)和热带风暴多莉(2014年)进入和越过墨西哥的马德雷东部山脉来研究。将研究地形锁定重力波和引发山区对流的作用，作为改变和延长热带气旋眼壁和雨带中降水的因素。通过研究这些类型的主要大气降水系统在越过山脉时对降水的增强作用，并确定关键因素，该项目将有助于更全面地了解山脉对降水云的影响。更广泛的影响：这项工作将为改进地球上最容易发生洪水和灾难性社会影响的地区的强降水预报奠定更广泛的影响。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的发生模式在不断变化的气候中可能会如何改变。此外，该项目将优化以往实地活动数据集的使用，并将有助于培训妇女和少数群体从事大气科学研究。

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.