Changes in the Frequency of Extreme Warm Season Surface Dewpoints in the Midwestern U.S.: Implications for Weather-Related Hazards

尽管上中西部是一个主要的农业区(即玉米和大豆)，并且经历了危险的热浪和频繁的暖季雷暴发展，但该地区的陆地-大气相互作用在很大程度上被忽视了。模拟研究表明，大陆中部地区的陆地-大气相互作用对全球引起的气候变化很重要，即使是微小的土地利用变化也可能对极端气候事件的发生产生重要影响。这项研究将发展数十年极端露点气候学，确定地面大气水分的时空分布，并确定有利于中西部上半部水汽汇集的区域。这将通过整合地面观测、高分辨率卫星数据和地理信息系统来实现。这些数据和工具将使研究人员能够确定土地覆盖、植被(包括农业)和地形在增强低层大气水分的时空分布方面的作用。确定暖季低层大气水汽及其源区的空间分布将有助于我们对有利于中西部上地区雷暴和危险热浪发展的形势的理解。通过详细描述和绘制暖季极端露点事件的演变图，我们将为预报员和其他研究人员提供工具，以减轻与热浪/热应激条件、反回声以及城市高温和高湿度组合相关的危险。我们还将向紧急服务机构和公众通报与极端露点事件相关的详细区域风险。

Land - atmosphere interactions in the Upper Midwest have been largely ignored even though it is a major agricultural region (i.e. corn and soybean) and is an area that experiences dangerous heat waves and frequent warm season thunderstorm development. Modeling studies suggest that land - atmosphere interactions in mid-continental locations are important for global induced climate changes and that even subtle land use changes may have important impacts on the occurrence of climate extremes. This study will develop a multi-decadal extreme dew point climatology, determine the temporal and spatial distribution of surface atmospheric moisture, and identify regions favorable to moisture pooling in the Upper Midwest. This will be achieved by integrating ground-based observations, high-resolution satellite data, and geographic information systems. These data and tools will allow the investigators to determine the role of land cover, vegetation (including agriculture), and topography in enhancing the spatial and temporal distributions of low-level atmospheric moisture. Determining the spatial distribution of low-level atmospheric moisture and its source regions during the warm season will forward our understanding of patterns conducive to the development of thunderstorms and dangerous heat waves in the Upper Midwest. By detailing and mapping the evolution of warm season extreme dew point events, we will provide tools to forecasters and other researchers in mitigating the hazards associated with heat waves/heat stress conditions, derechos, and the combination of urban heat and high humidities. We will also inform emergency service agencies and the public of detailed regional risks associated with extreme dew point events.