Observations of High Altitude CO2 Hot Bands in Mars Global Surveyor TES Limb Tangent Spectral Averages
Abstract
The MGS/TES instrument has now been in orbit for about 1.5 Martian years. Using respectively 6.45 and 12.5 cm-1 resolution observations from late Martian winter (Ls = 323o) to minimize the water vapor content, we have produced long-tangent-path limb spectral averages for one of six available detectors over successive 5 km vertical extents, beginning at 15-20 km. All of these averages show the strong 15μ m CO2 fundamental. At lower altitudes, as expected the broad 850-1300 cm-1 dust contribution to the limb radiance obscures other features in this extended spectral region. This is consistent with models of vertical dust profiles which, however, show a rapid decrease in dust concentration above 3-4 scale heights ( ~ 40 km). Features at both 10.4 and 9.5μ m are readily observed in the 35-40 km average. The former feature we identify as a CO2 hot band while the latter is comprised partly of another CO2 hot band. The ~ 100 cm-1 wide feature at 9.5μ m is visible in both low and intermediate resolution averages. Since this feature first becomes readily apparent in the 35-40 km average and is narrower than the broad dust contribution, we conclude it's not integral with the broad dust feature. On the other hand, the 9.5μ m feature is wider than can be accounted for by modeling the adjacent CO2 9.4μ m hot band. We will discuss the 9.5μ m feature in more detail. This work was supported in part by NASA's Mars Data Analysis Program.
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #32
- Pub Date:
- October 2000
- Bibcode:
- 2000DPS....32.5125M