HR: 0830h
AN: P51C-0464    [PDF]
TI: Passive Microwave Sounding of Jupiter's Atmosphere From an Orbiting Spacecraft
AU: * Hofstadter, M D
EM: Mark.D.Hofstadter@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Gulkis, S
EM: Samuel.Gulkis@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Kamp, L W
EM: Lucas.W.Kamp@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Levin, S M
EM: Steven.M.Levin@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Bolton, S J
EM: Scott.J.Bolton@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Janssen, M A
EM: Michael.A.Janssen@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Ingersoll, A P
EM: api@gps.caltech.edu
AF: California Institute of Technology, 150 A. S. Mudd 1200 E. California Blvd., Pasadena, CA 91109 United States
AB: The brightness temperatures of Jupiter at wavelengths from 1 to 100 cm provide important constraints on the distribution of microwave opacity in the Jovian atmosphere. At Jupiter, these wavelengths probe the atmosphere between ~1 and 1000 bars. The microwave opacity is most sensitive to the gaseous ammonia and water abundances as functions of height and location on the planet but other sources of opacity may also be present. It is difficult to determine a precise water abundance from nadir measurements alone because of the dominating absorption due to ammonia in the upper atmosphere. Even if the physical properties of the atmosphere were known precisely and the absorption properties of all of the absorbers were known, radiometer noise and calibration limitations will set limits to the accuracy at which the ammonia and water can be retrieved. We examine in this paper the impact of including the relative brightness of nadir and off-nadir views, which can be known much more precisely than the absolute brightness. This greatly improves the ability to measure simultaneously the water and ammonia abundances on Jupiter, relying on the fact that water and ammonia have different altitude distributions due to their different vapor saturation laws. We will also discuss how differential measurements from place to place on the planet can be used to constrain the ammonia and water abundances.
DE: 5704 Atmospheres--composition and chemistry
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting