Lightning and Moist Convection on Jupiter and Saturn

本项目将研究巨行星大气中的闪电和湿对流及其与云和大尺度环流的相互作用。闪电指示潮湿对流发生的地方。湿润对流调节着巨行星在其一生中的冷却，并且在较短的时间尺度上，有助于维持像全球喷流和像大红斑这样的巨大椭圆这样的大规模特征。该项目有两个主要组成部分：(1)通过分析来自卡西尼成像系统的木星和土星的档案数据来表征闪电。闪光的水平宽度、它们的光能和光谱是闪电深度和充电机制的线索。(2)用最先进的模型模拟湿对流动力学。提出建议的团队将修改现有的天气研究与预报（WRF）模型，以模拟巨行星大气的深层亚云层。通过在东部和西部急流之间嵌套一个高分辨率的计算域，他们将研究小尺度过程，如对流、降水和闪电，因为它们与大尺度气流相互作用。该团队将培训研究生并让他们参与研究，将修改后的GiantPlanetWRF模型提供给研究界，并将压缩和分析的卡西尼号图像存档在行星数据系统中。

This project will study lightning and moist convection in giant planet atmospheres and their interaction with clouds and the large-scale circulation. Lightning indicates where moist convection is occurring. Moist convection regulates the cooling of the giant planets over their lifetimes, and, on shorter timescales, helps sustain large-scale features like the global jet streams and giant ovals like the Great Red Spot. The project has two main components: (1) Characterize lightning by analyzing archival data on both Jupiter and Saturn from the Cassini imaging system. The horizontal width of the flashes, their optical energy, and their spectrum are clues to the depth of the lightning and the charging mechanism. (2) Simulate the dynamics of moist convection with a state-of-the-art model. The proposing team will modify the existing Weather Research and Forecasting (WRF) model to simulate the deep sub-cloud layer of giant planet atmospheres. By nesting a high resolution computational domain between eastward and westward jet streams, they will study small scale processes like convection, precipitation, and lightning as they interact with the large-scale flow. The team will train and involve graduate students in the research, will make the modified GiantPlanetWRF model available to the research community and will archive the reduced and analyzed Cassini images in the Planetary Data System.