Simulating Martian boundary layer water ice clouds and the lidar measurements for the Phoenix mission

Abstract

Diurnal variation of ground fog and water ice cloud formation at the NASA Phoenix lander site is investigated using a one‐dimensional Mars Microphysical Model (MMM) coupled with the results from the one‐dimensional University of Helsinki atmospheric boundary layer (ABL) model. Phoenix is scheduled to reach Mars in May 2008 and land in the northern plains (65°–72°N). Observations from Mars Global Surveyor Thermal Emission Spectrometer for the proposed landing site and season Ls = 76°–125° have been used for the model initialization, both in the ABL and MMM. The diurnal variations of temperature and eddy diffusion coefficients produced by the uncoupled ABL are then applied to the MMM. Extinction and backscattering coefficients and lidar ratios are presented for the simulated dust and water ice clouds at the Phoenix location. Results of the dust and ice clouds are then used to simulate the Phoenix lidar measurements at two wavelengths, 532 and 1064 nm.