85th AMS Annual Meeting

Sunday, 9 January 2005
An examination of Jupiter's Great Red Spot and other vorticies using the EPIC Model
Christopher J. Melick, University of Missouri, Columbia, MO; and H. Md. Anip, A. Kunz, R. Morales-Juberias, A. R. Lupo, and P. S. Market
Poster PDF (730.7 kB)
The Great Red Spot (GRS) on Jupiter is a great anti-cyclonic storm akin to a blocking high on earth, but it is enormous (semi-major axis > 22,000 km) and it has been continuously observed for at least 120 years. Historically, several studies have been conducted by many researchers in order to understand its nature, however, some physical processes related to it have not been entirely explained yet. In order to determine the various thermodynamic and dynamic processes influencing the atmosphere surrounding the GRS, this study utilized data generated from the EPIC model developed at the University of Louisville. Students at the University of Missouri utilized this model in order to perform this study as part their semester-long project. This project was aimed at demonstrating the general applicability of the principles and physics of weather and climate to atmospheres of any composition. Jupiterís temperature and pressure fields were first diagnosed so as to get a general synopsis of the weather pattern depicted by the EPIC model. Synoptic-scale vertical motions were calculated from the isentropic method, with results indicating that the pressure transport term was generally a more significant contributor to vertical motions. In order to check these estimates, forcing mechanisms from the QG omega equation were also evaluated. The calculated values for the large-scale vertical motions were found to be typically on the order of 0.1 Ķbs-1 at the lower altitudes, with a decrease in magnitude upon reaching the upper atmosphere. Even though the weak thermal gradients at each isentropic level suggest that Jupiterís atmosphere in the region studied might appear to have a baroclinic component, further analysis using the barotropic instability condition indicates that the atmosphere is very stable with respect to horizontal shear.

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