Lightning and Moist Convection on Jupiter and Saturn

California Institute Of Technology, Pasadena CA

Investigators

Abstract

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.