Mapping Mariner 9 Dust Opacities
Abstract
The study of the structure of Martian global dust storms can greatly contribute to our understanding of both interannual weather patterns and climatic trends on Mars. We present the results from a study of the spatial and temporal opacity variation of the 1971 global dust storm. Martin (Icarus vol. 66, 2-21, 1986) calculated dust opacities from Viking IR Thermal Mapper data. We use the same procedure with Mariner 9 IR Interferometer Spectrometer data by convolving IRIS spectra with IRTM filter functions, and thus derive 9 mu m optical depths. The opacities are mapped and binned by solar longitude to study the spatial structure of the 1971 dust storm. We have also calculated storm decay constants for different regions. We find that: 1. There is a diminishing spatial variation in opacity as the storm decays. 2. The highest opacities are found in the southern tropics; the lowest opacities are consistently in the southern polar region. 3. The storm dissipates more slowly near the equator, in accordance with previous results (Anderson and Leovy, J. Atmos. Sci., 35, 723-734, 1978).
- Publication:
-
AAS/Division for Planetary Sciences Meeting Abstracts #28
- Pub Date:
- September 1996
- Bibcode:
- 1996DPS....28.0309F