Thermal structure of Mars’ middle and upper atmosphere: Understanding the impacts of dynamics and solar forcing | CU Experts

We report six years of observations of dayside temperatures of the; middle and upper atmosphere of Mars made by the Imaging Ultraviolet; Spectrograph instrument aboard the MAVEN spacecraft. Thermospheric; temperatures show strong long-term variability associated with Martian; season and solar cycle. Temperatures from both the Martian thermosphere; and mesosphere show strong short-term variability indicating coupling; from the lower atmosphere. The observed local time effect is strong in; both upper and middle atmosphere temperatures. The thermosphere tends to; be colder in the morning compared to the evening when temperatures are; higher. Middle atmospheric temperatures show cooling during the dawn and; dusk hours. Our analysis shows strong tidal activity during aphelion,; whereas non-migrating tides are suppressed during perihelion, possibly; due to increased dust activity. Observations during the deep minimum of; solar cycle 24 reveal that thermospheric temperatures are highly; variable with respect to local time if solar forcing, Mars-Sun distance,; and spatial effects are removed. We will discuss these results in the; context of coupling between the lower and upper atmosphere of Mars.

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