SATURN 1991-1993 - REFLECTIVITIES AND LIMB-DARKENING COEFFICIENTS AT METHANE BANDS AND NEARBY CONTINUA - TEMPORAL CHANGES

DOI: 
10.1006/icar.1995.1159
Publication date: 
01/10/1995
Main author: 
ORTIZ, JL
IAA authors: 
ORTIZ, JL
Authors: 
ORTIZ, JL; MORENO, F; MOLINA, A
Journal: 
ICARUS
Publication type: 
Article
Volume: 
117
Pages: 
328-344
Number: 
Abstract: 
We present results on the variations of Saturn's reflectivity as a function of latitude and longitude for 3 consecutive years (1991-1993) in the 0.6- to 0.96-mu m spectral range. We found a strong decrease in methane absorption at equatorial latitudes from 1991 to 1992 and 1993, the most dramatic variations corresponding to the strongest 8900-Angstrom band. Changes in the limb-darkening behavior in both the continuum and methane absorption bands were also detected, implying considerable variations in the physical parameters of the tropospheric haze. Particularly, the change in the continuum Minnaert limb-darkening coefficients is comparable to that observed during the 1990 ''storm'' in the equatorial region. A remarkable asymmetry in the E-W curve of the absorption in the 6190-Angstrom methane band was found in 1992 mainly at equatorial latitudes. We confirm a high variation of the continuum reflectivity as a function of wavelength as detected by J. L. Ortiz et al. (1993, J. Geophys, Res, 98, 3053-3053), the dependence being different for distinct latitudes, with a darker southern hemisphere at the longest wavelengths. This N-S asymmetry was detected in the whole period 1991-1993. (C) 1995 Academic Press, Inc.
Database: 
WOK
SCOPUS
Keywords: