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

Abstract

[1] 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 L s = 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.

MGS TES observations of the water vapor above the seasonal and perennial ice caps during northern spring and summer

“…Numerical modeling of the water vapor diurnal behavior (Zent et al, 1993;Pathak et al, 2008), and recent observations by Phoenix Lander Tamppari et al, 2010;Whiteway et al, 2009;Daerden et al, 2010) and orbiting instruments on Mars Express (e.g. Tschimmel et al, 2008) indicate that large proportion of the atmospheric water vapor may be confined to a near-surface layer from 100 m to 1-2 km thick in the afternoon (at the time of TES nadir observations analyzed here) and that cloud formation and precipitation at night may keep water vapor confined to heights below 4-6 km above the surface.…”

Lidar on the Phoenix mission to Mars

“…There is also a thin cloud at a height of 1.5 km. It is expected that such thin water ice clouds will be detected in the atmosphere of Mars during the Phoenix mission [ Clancy et al , 1996; Montmessin et al , 2004; Pathak et al , 2008].…”

“…This affects local and global meteorological patterns which in turn determine the lifting of dust from the surface and long‐range transport [ Leovy , 2001; Newman et al , 2002]. There is also a climate interaction with the distribution of water ice above and below the surface of Mars [ Boynton et al , 2002; Pathak et al , 2008]. This involves transport of water through the atmosphere and previous measurements from orbit have indicated that clouds could play a substantial role [ Clancy et al , 1996; Neumann et al , 2003].…”

Ice nucleation by surrogates of Martian mineral dust: What can we learn about Mars without leaving Earth?

“…[3] Models from single cloud resolving to planetary scale have been developed to describe the nucleation, evolution, and precipitation of these clouds [Pathak et al, 2008;Daerden et al, 2010;Montmessin et al, 2002;Montmessin et al, 2004]. Several models consider cloud nucleation and microphysics, which have not been directly measured, by simple assumptions and/or analogies to terrestrial observations.…”