Properties of Limb Clouds at Mars determined from the Emirates Mars Mission (EMM) eXploration Imager (EXI)

Observations of clouds in planetary atmospheres can provide insight about atmospheric characteristics such as vertical temperature structure and dynamics. Clouds observed at the limb of a planet (from the perspective of the telescope or spacecraft observing them) can be particularly useful tools, in part because their height above the surface can be measured directly.

The Emirates Mars Mission (EMM) has been recording visible light images of the Martian disk since early 2021, using the Emirates eXploration Imager (EXI). We present an analysis of limb clouds evident in EXI images taken using its red filter (centered on 635 nm) over the course of a Martian year. We present statistics on their height, thickness, spatial extent, and geographic and local time distribution – as well as correlations between these parameters. We place our results in context with previous work, and explore reasons for observed trends.