JUPITER ATMOSPHERIC PARAMETERS DERIVED FROM SPECTROSCOPIC OBSERVATIONS IN THE RED REGION DURING THE 1988 OPPOSITION

Spectroscopic observations of several selected regions of Jupiter during the 1988 International Jupiter Watch Week (centered at planet opposition) are reported. High signal-to-noise ratio charge-coupled device (CCD) spectra of the most characteristic zones and belts have been obtained. The spectra were obtained with a nominal dispersion of 55 angstrom mm-1 in the lambda-lambda-6000-6600 angstrom wavelength interval at the coude focus of the 1.52 m telescope at Calar Alto Observatory (Spain). The northsouth scans obtained show a slight increase in absorption in belts with respect to nearby zones in both methane 6190 angstrom and ammonia 6450 angstrom absorption bands. The centre-to-limb variations in the equivalent widths of these absorption features show an asymmetric shape, the absorption being greater to the West than to the East for any given fractional radius. All of these phenomena are explained using sophisticated two-cloud models.