Temperature and para hydrogen gradients on Jupiter observed from the FORCAST camera on SOFIA

Jupiter was observed on December 8, 2010 with SOFIA using the FORCAST mid-infrared camera with selected spectral channels in the 5-40 μm region. Although the channels were not optimized for planetary observations, we demonstrate that useful information on latitude gradients of upper tropospheric temperature and the para hydrogen fraction ƒ_p can be retrieved. Calibration of the data is refined using simultaneous measurements of Callisto, along with a simplified model of Callisto's thermal behavior. In this preliminary study, an inversion algorithm is applied to measurements in three channels to obtain temperature and ƒ_p as functions of latitude in an atmospheric layer centered near 300 mbar. The results are compared with those previously obtained from Voyager IRIS, Cassini CIRS, and ground-based measurements. The low-latitude minimum in ƒ_p is found to be significantly displaced northward from the equatorial minimum in temperature, unlike the gradients found in the earlier Voyager and ground-based measurements. Possible explanations for this behavior are explored.