Wed Jul 20 00:10:29 1994
OSIRIS spectra of impact site E near 2:30 UT on 7/18
taken at the CTIO 4-meter show prominent CH4 absorption
lines at 2.20, 2.30, and 2.32 microns, allowing an
estimate of the cloud altitude from the CH4 abundance
above the cloud layer.
We made model spectra between 4300 and 4700 cm-1. The model includes CH4 absorption and solar reflection, and the basic model is similar to that of Kim et al. (Icarus, v. 91, p. 145, 1991). We found that the cloud deck should occur around 2 mbar level, assuming a normal CH4 mixing ratio in undisturbed Jupiter. However, since the explosion would bring up low altitude CH4 to high stratosphere where CH4 mixing ratio is lower, the 2 mbar should be the lower limit of the cloud deck altitude.
Usually NH3 cloud occurs at the 300 - 600 mbar level, and the polar haze occurs at the 10 - 20 mbar level.
No observations from here today, and yesterday we only obtained a single 2.3 micron image, at 00:05 on 7/19, during a 10-second (!) break in the clouds. This image showed sites C, A, E, and H, with A still very prominent after 52 hours, but much less bright than E and H. Hope for better weather tomorrow...
John Spencer, Darren Depoy, Sang Kim, OSIRIS, CTIO 4-meter.