Observations and Models of Storms on Jupiter and Saturn

这个项目将研究巨行星上的潮湿（水基）对流和闪电。潮湿对流是地球和巨行星上的一个基本过程，当上升的空气包中多余的水蒸气凝结成云时就会发生。它可以调节巨行星的冷却，帮助维持木星的巨大红斑，并为较小的风暴提供能量。闪电的区域表明潮湿对流发生的地方，因此研究人员将从结合土星和木星上的闪电风暴图像开始，这些图像是由卡西尼号航天器的各种仪器以不同的波长拍摄的。他们还将关注2010-2011年间发生在土星上的巨大雷暴。他们还将模拟大气动力学，以便更好地理解土星风暴之间的几十年间隔，对流在木星和土星冷却中的作用，深水丰度，以及产生纬向喷流的机制。结果将是一幅三维图像，显示云层的分布、组成和运动，以及它们与对流和闪电的关系。他们将把他们的研究纳入大学课程，并培养一名研究生，并将公开GiantPlanetWRF建模工具，用于模拟行星内部完全随时间变化的动力学。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。

This project will study moist (water-based) convection and lightning in giant planets. Moist convection is a fundamental process on Earth and the giant planets that occurs when excess water vapor in a rising air parcel condenses to form a cloud. It may regulate the cooling of the giant planets, help sustain Jupiter's Giant Red Spot, and provide energy for smaller storms. Areas of lightning indicate where moist convection is occurring, so the researchers will begin by combining images of the lightning storms on Saturn and Jupiter, taken by a variety of Cassini spacecraft instruments at different wavelengths. They will also focus on giant lightning storms on Saturn that occurred during the years 2010-2011. They will also model the atmospheric dynamics in order to better understand the multi-decadal intervals between Saturn's storms, the role of convection in Jupiter's and Saturn's cooling, and the deep water abundance, and the mechanisms for producing zonal jets. The result will be a 3-D picture of the distribution, composition, and motion of the clouds and their relation to convection and lightning. They will incorporate their research into university courses, and train a graduate student, and will make publicly available the GiantPlanetWRF modeling tool for modeling the full time-dependent dynamics of the planetary interior.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.