Urban Influences on Clouds, Precipitation and Lightning

根据这一奖项，首席调查员将继续研究城市环境对云和降水的影响。在以前的NSF支持下，敏感性试验的结果表明，城市热岛是诱发主要城市地区下风向深层湿对流的一个因素。城市热岛驱动的地面辐合在城市背风面增强。城市动量拖曳与城市热岛的非线性相互作用导致城市下风向对流，并伴随着降水的增加。在目前的奖项下，首席调查员将从事以下活动：-模拟增强的云凝结核和巨型云凝结核浓度对对流的影响。-理想化模拟和城市地区对中尺度对流系统的影响的案例研究。-参与休斯顿环境气溶胶雷暴项目(HEAT)。HEAT处于规划阶段，是一个多人参与的项目，旨在调查城市环境对天气的影响。首席调查员的模拟工作将有助于这个项目的规划。-模拟城市对对流和有利于闪电的云结构的影响。这项研究将有助于从根本上了解主要城市中心对对流风暴、闪电和降水的影响。这项研究将对城市土地利用规划产生更广泛的影响。教育方面的好处是，这项工作的成果将立即纳入第一年的课程内容和云物理和云动力学的高级课程，以及首席研究员与人合著的教科书《人类对天气和气候的影响》。

Under this award, the Principal Investigator will continue research on the influence of the urban environment on clouds and precipitation. Under prior NSF support, which was focused on dynamical influences, results of sensitivity experiments have shown that the urban heat island is a factor in inducing deep, moist convection downwind of a major urban area. Surface convergence driven by the urban heat island is enhanced on the leeward side of the city. The nonlinear interaction between urban momentum drag and the urban heat island causes convection downwind of the urban area with a concomitant increase in precipitation. Topography is also shown to impact storm development.Under the current award, the Principal Investigator will undertake the following activities:-Modeling the effects of enhanced cloud condensation nuclei and giant cloud condensation nuclei concentrations on convection.-Idealized modeling and a case study of impacts of an urban area on mesoscale convective systems.-Participation in the Houston Environmental Aerosol Thunderstorm Project (HEAT). HEAT is in the planning stages and is a multi-investigator program designed to investigate the influence of the urban environment on weather. The Principal Investigator's modeling work will be helpful in the planning of this project.-Modeling urban impacts on convection and cloud structures favorable for lightning.This research will contribute to fundamental understanding of the influence of major urban centers on convective storms, lightning, and precipitation. The broader impacts of this research will be on urban land-use planning. The educational benefit is that results of this work will be immediately incorporated in the course content of first year and advanced courses in cloud physics and cloud dynamics, as well as in the textbook "Human Impacts on Weather and Climate" co-authored by the Principal Investigator.