Cover Page/Proposal Summary

ROSS-00    NRA 00-OSS-01

Date Due: 4/28/2000

The major goal of the proposed research is to refine our knowledge of the chemical processes that are currently taking place in the atmospheres of giant planets and their satellites. This investigation will provide a solid theoretical framework from which to interpret several interesting recent observations. An important secondary goal of the work is to understand how differing physical properties such as atmospheric temperature, ultraviolet flux, or the strength of atmospheric mixing can engender differences in the observed chemical composition of atmospheres within our own solar system (e.g., Jupiter vs Saturn) and beyond (e.g., Jupiter vs the T dwarf Gliese 229B). During this funding cycle, our primary focus will be on developing photochemical models for Jupiter, Gl 229B, and Io. The photochemical models of Jupiter's upper atmosphere will be compared with recent ISO observations of hydrocarbon and oxygen compounds to place better constraints on the flux of external oxygen-bearing material into Jupiter's atmosphere and to better understand the quantitative details of hydrocarbon photochemistry on the outer planets. The Jovian model will serve as a starting point for models of C-H-O-N-S photochemistry on Gl 229B. These models will help determine whether photochemistry can alter the predicted equilibrium composition (and hence the observable spectrum) of the T dwarf and will illustrate how changes in parameters such as temperature, gravity, ultraviolet flux, and metallicity can affect the composition of the atmospheres of extrasolar giant planets and brown dwarfs. Finally, our models of photochemistry near an active volcanic plume on Io will be compared with recent HST and ground-based observations to better understand the role of volcanoes in maintaining Io's atmosphere.

Certification of Compliance with Applicable Executive Orders and U.S. Code

By submitting the proposal identified in this Cover Sheet/Proposal Summary in response to this NRA or AO, the Authorizing Official of the proposing institution (or the individual proposer if there is no proposing institution) as identified below: