User:VMKarnes/Climate of Mars

Katabatic Winds and Jumps
Katabatic winds, or drainage atmospheric flows, are winds that are created by cooled dense air sinking and accelerating down sloping terrains through gravitational force. Found most commonly on Earth effecting the elevated ice sheets of Greenland and Antarctica, katabatic winds can also be found effecting parts of Mars with intense clear-cut downslope circulations, such as Valles Marineris, Olympus Mons, and both the northern and southern polar cap. They can be identified by multiple different surface morphological features in the polar regions, such as dune fields and frost streaks. Due to the low thermal inertia of Mars’ thin CO2 atmosphere and the short radiative timescales, katabatic winds on Mars are two to three times stronger than those on Earth and take place on large areas of land with weak ambient winds, sloping terrain, and near-surface temperature inversions or radiative cooling of the surface and atmosphere. Katabatic winds have been instrumental in shaping the northern polar cap and the polar layered deposits, both in aeolian methodology and thermal methodology. It has also been shown that the acceleration of katabatic winds increases with the steepness of the slope and causes atmospheric warming the more intense the slope is. This atmospheric warming could appear over any steep slope, but this does not always equal surface warming. They also are shown to limit CO2 condensation rates on the polar caps in the winter and increase CO2 sublimation in the summer. Though quantitative measurements of katabatic winds are rarely available, they remain a highly sought-after element for upcoming missions.

Katabatic jumps are also common in troughs on Mars and can be described as narrow zones with large horizontal changes in pressure, temperature, and wind speed that require super saturated water vapor to form clouds and enable ice migration from the upstream part of the trough to the downstream. For this reason, the polar caps see less katabatic jumps in winter, as the seasonal ice cap that covers the polar regions means there is less water ice available to create vapor. However, even when the seasonal cap has sublimated over the course of the Martian summer, the fast winds necessary for katabatic jumps are no longer present, meaning the cloud cover is again negligible. Therefore, katabatic jumps are most commonly seen in troughs during the Martian spring and Martian fall.