High-Resolution 10-micronmeter Spectroscopy of Ammonia and Phosphine Lines on Jupiter

latitudes 308–358S. This variation is not correlated with the 200-mbar temperature. It can be explained by a decrease of High spectral resolution measurements of NH3 and PH3 lines the eddy mixing coefficient near 240 mbar from p4000 to #400 on Jupiter in the 10.5to 11.2-mm range are presented. Observacm sec between the two latitude ranges. The PH3 mixing tions, recorded on January 21–23, 1991, cover the 108–408S ratio near 580 mbar lies between 1.7 and 2.6 3 10 in the latitude range and several longitudes including the Great Red observed regions. At all longitudes, PH3 varies smoothly with Spot (GRS). Information on the temperature in the upper tropolatitude, decreasing by p30% from 108 to 358S. This variation sphere was retrieved from the continuum radiance at wavemay also reflect a decrease in the strength of the eddy mixing lengths around 12.8 and 17.8 mm. At all observed longitudes, near 580 mbar or at deeper levels in the atmosphere.  1998 the 200-mbar temperature field is minimum at latitudes of Academic Press 208–258S near the location of the South Tropical Zone, in