Martian dust storm hazards: improving characterization and forecasting

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Thursday, 21 January 2010: 2:30 PM
B211 (GWCC)
Nicholas Heavens, California Institute of Technology, Pasadena, CA; and M. I. Richardson, I. J. McEwan, and M. W. Busch

Dust storms are Mars's principal type of extreme weather system, capable of obscuring the planet on mesoscale to global scales. In addition, the scale, location, and seasonal timing of their occurrence provide the most obvious examples of interannual variability in the modern Martian climate. Dust storms already create visibility, power management, and other hazards for unmanned spacecraft and almost certainly will create similar and other hazards for future human explorers of Mars and their support systems. Therefore, characterization and forecasting of dust storm hazards is a leading problem in applied martian meteorology.

Here, we present two relevant investigations. First, we adapt Emanuel's steady-state hurricane theory to martian dust storms. Our results suggest that the necessary wind velocity for sustaining a martian dust storm is controlled by the threshold velocity for lifting dust and factors related the structure of the storm and the background atmosphere such as the thermodynamic efficiency. Recent observations suggest that winter hemisphere gravity wave activity could control the initial outflow temperature of southern hemisphere dust storm activity and could determine whether a storm becomes global-scale or not.

Second, we describe a method in which radio emission from discharges near the surface of dust storms can be used to map the intensity of dust storm activity, thereby elucidating dust storm structure and rate of intensification.