Knowledge Bank

Since our observation of the 3.544 $\mu$m $2v20\to v2$($J=9K=9\to J=8,G=9,U=1$) hot band transition of $H3+$ in the polar regions of $Jupitar,a$ we have pursued the simultaneous detection of additional hot band transitions with fundamental band transitions in order to derive well determined $H3+$ excitation temperatures. We report 9 additional resolved $2v22\to v2$ and $v1+v2\to v1$ hot band transitions observed in emission at 3.52, 3.63, 3.66, and 3.84 $\mu$m. The hot band transitions have thus far only been detected in the polar regions, with the occasional exception being the 3.544 $\mu$m $2v02\to v2$ transition around $45\prime$ S latitude during the 1994 Comet Shoemaker Levy-9 encounter. Temporal and spatial variation of the excitation temperatures as well as their dependence on vibrational mode will be presented. Anomalous line intensities, e.g. , will also be discussed. All observations were made with the CGS4 spectrometer at the United Kingdom Infrared Telescope on Mauna Kea, Hawaii.