Mars boffins reckon they've found seasonal found patterns in Mars' dust storms.
Detailed in a Geophysical Research Letters research letter titled Interannual similarity in the Martian atmosphere during the dust storm season, David Kass, who runs the Mars Climate Sounder, and co-authors identify:
- Type A storms, that start as polar storms moving south. Big polar storms can spread far enough that they reach warmer climes. When that happens in southern-hemisphere spring, that extra warmth adds enough energy to boost wind speeds and spread the storm across the red planet.
- Type B storms, that usually pop up near Mars' south pole before the beginning of southern summer. In some years a few can occur and make some “regional haze”.
- Type C storms get their moment to shine in the northern winter, then move to the southern hemisphere. While identifiable, NASA says Type C storms vary more, in terms of temperature and duration, than the other two types.
The three types were observed using the Mars Reconnaissance Orbiter and its onboard Mars Climate Sounder. That craft and instrument have been orbiting Mars since 2006, when they arrived just in time to take over from the ailing Mars Global Surveyor that did the job since 1997.
The two orbiters' presence means we've got almost 20 years of lovely data about Mars to consider. The seasonal storm theory was derived from the most recent six years of observations.
Mars' dust storms are of considerable interest because dust absorbs heat and there's not much heat around on Mars. Knowing where and when temperatures will become even more uncomfortable than usual - dust storms can raise or lower temperatures by around 35 degrees celsius - is obviously useful when planning visits to the red planet. ®
Seasonal Temperature Pattern Indicating Martian Dust Storms