FIRST RESULTS OF ISO-SWS OBSERVATIONS OF JUPITER

The spectrum of Jupiter has been recorded between 2.75 and 14.5 mu m w ith the grating mode of the Short-Wavelength Spectrometer (SWS) of ISO . The resolving power is 1500. The main preliminary results of this ob servation are (1) at 3 mu m, the first spectroscopic signature, probab ly associated with NH3 ice, of the Jovian cloud at 0.5 bar and (2) the first detection of a thermal emission at the center of the CH4-nu(3) band at 3.3 mu m, showing evidence for a high temperature in the upper jovian stratosphere (T=800 K at P=0.16 microbar). In addition, the R( 2) HD line has been detected for the first time in Jupiter, using the Fabry-Perot (FP) mode of the SWS, with a resolving power of 31000. A p reliminary analysis of the HD line indicates a D/H ratio of about 2.2 10(-5).