Atmospheric effects on the remote determination of thermal inertia on mars

摘要: Abstract The thermal inertia of the uppermost 1–10 cm Martian surface is determined by comparing measurements infrared brightness temperature at many different times day with temperatures predicted a model. These models allow sunlight to reach unattenuated, and assume that emission atmosphere constant throughout equal 2% noontime insolation. We have assessed consequences these assumptions model allows for transfer radiation through dusty CO2 atmosphere, sensible heat exchange surface. radiative properties dust are “tuned” produce near-neutral greenhouse effect similar observed. Thus, averaged over day, absorption decreases solar flux an amount roughly increase in IR. However, increased downward IR, which can be two five greater than assumption depending on load, significantly reduces derived inertias. When using fit IRTM data Viking lander 1 site, example, 25% smaller based assumption. Smaller inertias imply particle sizes, our results suggest low-thermal-inertia regions consist particles closer 5 μm diameter rather 50 as was previously believed. This more consistent suggestions form atmospheric sedimentation. Finally, also appears capable explaining much, but not all, discrepancy between measured afternoon use assumptions, i.e., so-called “afternoon cooling” effect.