Off-season lee wave cloud over the Arsia Mons in Mars: A study based on Mars Colour Camera (MCC)

Abstract

The present analysis reported the lee wave interpretation on Arsia Mons Elongated Cloud (AMEC) that used to appear over the lee side of the Arsia Mons. The present work also reported the wavelength, the cloud's height, and wind speed of the observed lee wave structure. The estimated wind speed is 86 ± 4.9 m/s, with a wavelength of 60 ± 0.3 km at an altitude of 55 ± 7 km. This is the largest lee wave structure that appears during the dust storm season (Ls = 230 to Ls = 300) and strongly contributes to the planet's Albedo level. Calculated TOA reflectance varies from 0.05 to 0.15 for the blue channel and 0.02 to 0.09 for the red channel. Estimated AOD ranges from 1.8 (red channel) to 1.5 (blue channel), indicating the contribution of dust and water ice crystal. The estimated angstrom exponent (α) value signifies coarse mode particle presence in the cloud with an effective radius of 3.2 μm. The presence of water ice crystal contributes to the albedo level's increment to 0.8 and signifies the formation temperature for AMEC to be around 190 K.