Global Changes in Surface Dust Coverage using Mars Climate Sounder
Abstract
The current climate of Mars is punctuated by annually-recurring regional-scale, and occasional global-scale, dust events where dust is lifted high into the atmosphere and transported by the circulation. In the atmosphere, dust absorbs short-wavelength solar radiation, reducing the amount of sunlight reaching the surface, and increasing down-welling long wavelength radiation. On the surface, dust influences the albedo and thermal properties, hence the energy absorbed, by brightening soils, darkening ices, and thermally insulating the surface due to its low thermal inertia. Widespread changes in albedo, presumably associated with dust redistribution, are observed over mutliple timescales, however the amount, rate, and spatial variability concerning surface dust redistribution is not well understood. The redistribution of surface dust, assuming sufficient changes in both the thickness and areal extent, will result in changes in albedo and/or thermal inertia, which are expressed in the surface temperature signal. Thermal emission from the surface and atmosphere has been measured by the Mars Climate Sounder (MCS) infrared radiometer for ~7 Mars years, and allows for accurate derivation of the kinetic surface temperature. Daytime-nighttime pairs of surface temperature are used to quantify thermal inertia and surface albedo. These quantities are then interpreted in the context of changing dust thickness. Results will have implications for our understanding of the global transport of dust, the initiation of dust storms, and the overall climate of Amazonian Mars.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMP039...04B
- Keywords:
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- 0343 Planetary atmospheres;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 6225 Mars;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 5405 Atmospheres;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS;
- 5445 Meteorology;
- PLANETARY SCIENCES: SOLID SURFACE PLANETS