Submillimeter and millimeter observations of Jupiter

Using absolute calibrations referenced to Mars, narrowband photometry has been obtained for the Jovian disk in ten passbands covering the 0.35-3.3 mm wavelength range. Existing atmospheric temperature structure and composition constraints are taken as the context for an analysis of the derived brightness temperature spectrum. Results obtained for the 0.35-0.45 mm range are noted to suggest that radiances can be matched by models which include NH3 ice particles of 30-100 micron size. A 5-percent increase of the absolute calibration scale would yield results well fitted by a clear atmosphere model, obviating the supposition of additional Jovian atmosphere absorption.