Martian Water-ice Clouds
Mars’ atmosphere, while much drier than our own, is nevertheless driven by a seasonal water cycle wherein water vapour is exchanged between the atmosphere and the polar caps. One feature of this water cycle is the yearly Aphelion Cloud Belt (ACB) which occurs around when Mars reaches its furthest point from the sun. During ACB season, water-ice clouds form much more readily around the equatorial area of Mars. Curiosity, at about 5° south of the equator, is well positioned to observe the southern edge of the ACB.
My work has looked at the microscopic properties of water-ice crystals in these clouds, which we can infer from the ways sunlight interacts with the clouds. The way light is scattered is described by a curve called a ‘phase function’, and the phase function encodes information about particle size and shape. I can also use year-to-year observations to look at variability in ACB clouds between years, at different parts of the ACB season, and at different times of the martian day (which we call a ‘sol’).
I have also been involved in research determining how optically thick these clouds are, and how well orbital instruments are able to see optically thin ACB clouds. Additionally, I’ve been involved in looking at twilight noctolucent clouds, which we see near the beginning of the Mars year.
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Atmospheric Dust
Dust in the atmosphere is another large driver of the martian climate. Mars sees both small, short-term dust lifting events such as dust devils, and longer term, larger events like dust storms.
More to come
Martian Methane
Coming soon