Jovian Tropospheric Horizontal and Vertical Temperature Structure During the Galileo G1 Orbit
B.M. Fisher , G.S. Orton, M. Ressler, S. Hinkley (JPL,Caltech)
We observed Jupiter at 11 thermal infrared wavelengths
from 7.85 m to 24.5 m from June 26-July 1, 1996 using
the MIRLIN camera at the NASA IRTF. The observations were made in
support of the Galileo Ganymede-1 orbit to provide a global
perspective to compliment the high-resolution, limited-area spacecraft
observations. Our wavelength coverage allows
for sounding of the tropospheric temperatures at pressures of
approximately 100-500 mbar.
The sounding results in maps of temperature as a function of
latitude, longitude, and pressure. Good weather during the observation
period allowed for complete planet coverage. We apply the thermal wind
equation for geostrophic conditions to find latitudinal and longitudinal
wind shears as a function of pressure and location. Preliminary
results have shown evidence for a counter-rotating region in the center
of the Great Red Spot at the 250 mbar level.
Thermal wind shears are examined in detail at the latitudes
of the 5 m hot spots, the North Equatorial Belt (NEB) and
around the southern-hemisphere classical
white ovals. Considerable longitudinal structure is observed
in Jupiter's NEB. The vertical temperature structure of
these features is examined for evidence vertical shear in the rotation rates.
Temporal changes on the time scale of a few days are examined.
NASA/NRC Resident Research Associate
Caltech Summer Undergraduate Research Fellow