Spatial variations in the Jovian 20-micrometer flux

The 17–28 μm brightness temperature of the center of the disk of Jupiter is 136 ± 4 K. Model calculations yield an effective temperature of 142 ± 4 K at the center of the disk for a helium to hydrogen ratio He/H₂ of 0. This corresponds to an effective temperature of the entire disk of 136 ± 5 K. The NEB, SEB, and STeB are shown to emit an excess flux at 20 μm when compared to the neighboring zones. The hot belts were grey in color at the time of the observations and were the source of excess 5-μm flux as well (Keay et al. 1973). The relationships between 5-μm and 20-μm flux excesses and the cloud structures are discussed.