Measurements of the Charge, Size, and Type of Thunderstorm Precipitation Particles

9311749马歇尔：这项研究的目的是研究降水电荷是否对雷暴中的电力负有主要责任。为此，研究人员建议分析1991年对流和降水/带电实验(CAPE)期间在佛罗里达州10个雷暴内收集的降水粒子的电荷、大小和二维形状的数据。这些数据特别重要，因为测量的温度范围从-50摄氏度到-20摄氏度；尽管有迹象表明，风暴中的大部分电荷都是在那里产生的，但这个地区还没有得到很好的研究。根据形状测量，提出者可以确定降水粒子的类型：雨滴、雪花、冰雹或冰雹。然后，他们可以确定不同类型粒子上携带的电荷的极性和数量。PI将与国家大气研究中心(NCAR)的同事合作，寻找温度、云中液态水含量、云中粒子类型和数量、上升和下降气流、云中位置等对粒子电荷的影响。他们将把帆船测量的电场与测量的粒子电荷预期的电场进行比较；可比较的场将表明，在风暴的该部分，降水携带了大部分电荷。PIS将与NCAR的同事和其他CAPE研究人员合作，使用雷达数据，通过将帆船轨迹叠加到反射率数据和来自多个多普勒雷达分析的风场，将降雨量测量置于正确的风暴背景下。***

9311749 Marshall The objective of this research is to see if the charge on precipitation is primarily responsible for the electricity in thunderstorms. Toward this end, the investigators propose to analyze data of the charge, size, and two-dimensional shape of precipitation particles collected inside ten Florida thunderstorms during the 1991 Convection and Precipitation/Electrification Experiment (CaPE). These data are especially important because of the measurements in the temperature range from -5o to -20oC; this region has not been well studied despite suggestions that much of the charge in storms is generated there. From the shape measurements the proposers can determine the type of precipitation particle: raindrop, snowflake, hailstone, or graupel. They can then determine the polarity and amount of charge carried on different types of particles. The PIs will collaborate with colleagues at the National Center of Atmospheric Research (NCAR) to look for influences on particle charges by temperature, cloud liquid water content, cloud particle types and numbers, updrafts and downdrafts, position in the cloud, etc. They will compare the electric fields measured by the sailplane to the electric field expected from the measured particle charges; comparable fields will suggest the precipitation carries most of the charge in that part of the storm. The PIs will collaborate with NCAR colleagues and other CaPE researchers using radar data to place the precipitation measurements in their correct storm context by superimposing sailplane tracks on reflectivity data and on wind fields from multiple Doppler radar analyses. ***