Dynamics of the Jovian Atmosphere from Observation and Theory

Author: Li, Liming

Year: 2007

Degree: Dissertation (Ph.D.)

Advisor: Ingersoll, Andrew P.

Committee Members: Burnett, Donald S.; Ingersoll, Andrew P.; Richardson, Mark I.; Yung, Yuk L.

Option: Planetary Sciences

DOI: 10.7907/6DAY-FJ03

Abstract

The atmospheric dynamics of Jupiter is studied by the Cassini observations and numerical models.

The multi-filter imaging data sets and the global thermal maps acquired by two instruments on Cassini--the Imaging Science Subsystem (ISS) and the Cassini Composite Infrared Spectrometer (CIRS) during the Jupiter flyby, are utilized to study atmospheric activities on Jupiter including small-scale spots, the Great Red Spot (GRS), the Dark Oval (DO), the vertical structure of zonal winds, and wave propagation. These new observations enrich the library of atmospheric activities and offer more clues and constraints on theoretical studies.

A reduced-gravity quasi-geostrophic (QG) model is combined with a parameterization of moist convections based on observations, to study the interaction between moist convection and zonal jets on Jupiter and Saturn. The numerical experiments support the idea that the zonal jets get their energy from moist convective events. Strong jets in Jupiter and Saturn, which violate the barotropic stability criterion, are reproduced by assuming westward flows in the deep underlying layer. Furthermore, our simulations suggest that the width and strength of jets on Jupiter and Saturn are controlled by the classical Rhines scale and a new velocity scale determined by characteristics of moist convection.

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