Relationship between frontal dust storms and transient eddy activity in the northern hemisphere of Mars as observed by Mars Global Surveyor

Abstract

We have compiled a catalog of frontal dust storms in the northern hemisphere using Mars Orbiter Camera daily global maps spanning ~2.3 Martian years of Mars Global Surveyor (MGS) observations (from 1999 to 2003). The most vigorous frontal storms that flush dust to the low latitudes occur in early-mid fall and mid-late winter, away from the northern winter solstice. While many streaks are observed in the polar hood during the winter solstice period, no frontal dust storms are observed in the vicinity of the north polar region. We have also analyzed simultaneous MGS Thermal Emission Spectrometer (TES) temperature data and found statistically significant negative temperature anomalies associated with frontal storms. In the lowest scale height of the atmosphere, the geographical and seasonal distributions of temperature standard deviations associated with transient variations agree well with the distributions of frontal storms. The correlation deteriorates with increasing altitude, suggesting that lower-level temperature waves are associated with the frontal dust storms. Specifically, eastward traveling m = 3 waves with periods of 2–3 sols appear to be closely related to the development of flushing frontal storms.

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