Numerical Simulation and Analysis of Convective Storms

在春季和夏季，中尺度对流系统带来了最有利的降雨，以及龙卷风、冰雹、山洪暴发和大风等破坏经济和危及生命的现象。中尺度对流系统是雷暴的集合，在典型尺度上覆盖数百公里的区域，寿命超过一天。作者提出了一种观测分析和数值模拟相结合的方法，以进一步了解中尺度对流系统。所使用的观测数据是在以前由国家科学基金会赞助的实验中收集的。研究目标包括：1.；具有随机雷暴模式的中尺度对流系统的分析和模拟。目的是确定为什么有些系统发展出这些随机降水模式，而另一些系统则表现出线性结构。2. 使用雷达反射率场来识别体积降雨率的脉动和中尺度对流系统在其生命周期中的其他形态特征。3. 我们注意到，一些中尺度对流系统往往会产生强烈的风暴，其中大部分破坏发生在天气尺度暖锋的北侧。首席研究员将使用数值模拟和观测分析相结合的方法来确定对流尺度和中观/天气尺度特征的哪种组合会导致强风。4. 利用先进的数值技术，首席研究员将研究天气、中尺度和中尺度之间的动力学相互作用。

During the Spring and Summer months, mesoscale convective systems account for most beneficial rainfall as well as economically disruptive and life-threatening phenomena such as tornadoes, hail, flash floods and high winds. Mesoscale convective systems are collections of thunderstorms that cover areas several hundreds of kilometers in typical dimension and have lifetimes of more than one day. The Principal Investigator proposes a joint observational analysis and numerical simulation approach in furthering knowledge of mesoscale convective systems. Observational data to be used are those that have been collected during previous experiments sponsored by the National Science Foundation. Among the research goals are: 1. Analysis and simulation of mesoscale convective systems which exhibit random patterns of thunderstorms. The objective is to determine why some of these systems develop these random precipitation patterns while others exhibit a line structure. 2. Use radar reflectivity fields to identify pulsations in volumetric rainfall rates and other morphological characteristics of mesoscale convective systems over their lifetimes. 3. It has been noted that some mesoscale convective systems tend to produce severe wind storms with most of the damage occurring on the north side of synoptic-scale warm fronts. The Principal Investigator will use a combination of numerical simulation and observational analyses to determine what combination of convective- scale and meso/synoptic scale features lead to severe winds. 4. Using advanced numerical techniques, the Principal Investigator will investigate the dynamical interactions between the synoptic, meso-alpha and meso-beta scale.