A multi-city analysis of the UHI-influence on warm season rainfall
A multi-city analysis of the UHI-influence on warm season rainfall
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DOI：
10.1016/j.uclim.2013.09.004
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发表时间：
2013-12
期刊：
影响因子：
6.4
通讯作者：
M. Ganeshan;R. Murtugudde;M. Imhoff
中科院分区：
文献类型：
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作者：
M. Ganeshan;R. Murtugudde;M. Imhoff
本研究利用当代高分辨率观测结果评估了城市热岛 (UHI) 对美国几个城市暖季降水的影响。使用统计方法分析与传播和非传播风暴相关的空间（局部和顺风）降雨异常。日趋势分析表明，城市热岛效应对内陆城市（明尼阿波利斯和华盛顿特区）的降水具有显着影响，特别是在下午和夜间。传播的风暴似乎集中在城市地区，但降雨加强发生在城市的下风处。过去较少受到关注的夜间降水异常显着且与白天异常相当。对于沿海城市（纽约市、普罗维登斯和克利夫兰），由于热岛-海风相互作用，白天极端正降雨异常的频率和强度可能会出现局部增加。对于非传播风暴，在内陆城市（达拉斯）的顺风处夜间降雨量明显增加，而沿海城市（休斯顿）则观察到当地白天强降雨事件的频率增加。对于沿海城市来说，顺风和夜间热岛对降雨的影响似乎不太明显。显然需要未来的研究来了解导致城市降雨增加的过程的可变性。
This study evaluates the influence of the Urban Heat Island (UHI) on warm season precipitation for several US cities by using contemporary high-resolution observations. Spatial (local and downwind) rainfall anomalies associated with propagating and non-propagating storms are analyzed using statistical methods. A diurnal trend analysis suggests that the UHI has a dominant influence on precipitation for inland cities (Minneapolis and Washington D.C.), especially during afternoon and nocturnal hours. Propagating storms appear to converge over the urban region, but the rainfall intensification occurs downwind of the city. The nocturnal precipitation anomaly, which has received less attention in the past, is significant and comparable to the daytime anomaly. For coastal cities (New York City, Providence and Cleveland), a local increase in the frequency and intensity of extreme positive rainfall anomalies may occur during daytime due to the UHI-sea breeze interaction. For non-propagating storms, nocturnal rainfall enhancement is evident downwind of an inland city (Dallas), whereas a local daytime increase in the frequency of heavy rainfall events is observed for a coastal city (Houston). Downwind and nocturnal UHI impacts on rainfall appear less obvious for coastal cities. Future studies are clearly needed to understand the variability in processes that produce urban rainfall enhancement.