Understanding the Consequences of Interactions between Deep Convective Storms and Large Cities

由于土地使用的特点，大城市可能对当地天气产生重大影响。 城市热岛是城市最著名的后果，但先前对降水和闪电的研究表明，城市也会影响雷暴的位置和强度。 该奖项为城市风暴改造潜力的数值模拟研究提供资金，特别关注恶劣天气的潜力。 这项研究的目的是确定哪些风暴过程最受城市地区的影响，以及哪些城市特征最有可能改变重大风暴。 这项工作的结果将为业务预报员提供与公共安全有关的更多信息。 该奖项还将通过支持学生和为K-12教师开发学习模块来帮助培训下一代科学家，该项目旨在提高对深对流风暴与大城市地区之间相互作用的理解。 大多数以前的研究在该地区的风暴-城市相互作用集中在弱强迫事件和/或由此产生的降水从这些风暴，和社会还没有凝聚在周围的主要机制风暴修改（城市热岛（UHI），流动障碍，气溶胶，水分）。 这项研究将包括一个大的参数空间研究，调查城市参数和风暴修改之间的因果关系。 第一步将是基于CM 1的一组约150个理想化敏感性实验，网格大小为250米。 然后，WRF-ARW将被用来检查风暴修改的实例在路易斯维尔，肯塔基州周围的实际数据的情况下，使用10个成员的集合方法。 城市热岛指数将通过吸收城市周围30个观测点的数据进行调整。 最后，观测网络将用于分析对流降雨量的空间变化。 该提案将解决的首要问题是：1）哪些风暴过程最受大城市地区的影响？2)城市与风暴相互作用与恶劣天气可能性的关系是什么？3)不同的城市特征如何影响深对流风暴的变化？，4）环境风切变对城市改造有何影响？该项目由物理和动力气象学计划和激励竞争研究的既定计划（EPSCoR）共同资助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Large cities can have significant impacts on local weather due to land-use characteristics. The Urban Heat Island is the most well-known consequence of cities, but prior research on precipitation and lightning has provided an indication that cities can also affect the location and strength of thunderstorms. This award provides funding for a numerical modeling study of the potential for urban storm modification with a specific focus on severe weather potential. The intent of the study is to determine which storm processes are most affected by an urban area and which urban features are most likely to modify significant storms. The output from this work will provide operational forecasters with additional information relevant to public safety. The award will also help to train the next generation of scientists through support of students and the development of learning modules for K-12 teachers.This project intends to improve the understanding of interactions between deep convective storms and large urban areas. Most prior research in the area of storm-urban interactions has focused on weakly-forced events and/or the resultant precipitation from those storms, and the community has not coalesced around the dominant mechanism for storm modification (Urban Heat Island (UHI), flow obstruction, aerosols, moisture). This study will consist of a large parameter space study to investigate the cause-and-effect relationship between urban parameters and storm modification. The first step will be a CM1-based set of ~150 idealized sensitivity experiments, with grid sizes 250m. The WRF-ARW would then be used to examine instances of storm modification in real-data cases around Louisville, KY using a 10-member ensemble approach. The UHI will be adjusted by assimilating data from a network of 30 observation sites around the city. Finally, the observational network will be used to analyze the spatial variability in convective rainfall amounts. The overarching questions that the proposal would address are: 1) Which in-storm processes are most strongly affected by an encounter with a large urban area?, 2) What are the consequences of city-storm interactions as they relate to severe weather potential?, 3) How do different urban features impact the modification of deep convective storms?, and 4) What is the effect of environmental wind shear on urban modification?This project is jointly funded by the Physical and Dynamic Meteorology program and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.