P23B-2136
Constraining Atmospheric Particle Size in Gale Crater Using REMS UV Measurements and Mastcam Observations at 440 and 880 nm
Tuesday, 15 December 2015
Poster Hall (Moscone South)
Emily L Mason, Texas A & M University College Station, College Station, TX, United States, Mark T Lemmon, Texas A & M University, College Station, TX, United States, Manuel de la Torre-Juárez, Jet Propulsion Laboratory, Pasadena, CA, United States, Alvaro Vicente-Retortillo, Complutense University of Madrid, Madrid, Spain and German Martinez, University of Michigan Ann Arbor, Ann Arbor, MI, United States
Abstract:
Optical depth measured in Gale crater has been shown to vary seasonally, and this variation is potentially linked to a change in dust size visible from the surface. The Mast Camera (Mastcam) on the Mars Science Laboratory (MSL) has performed cross-sky brightness surveys similar to those obtained at the Phoenix Lander site. Since particle size can be constrained by observing airborne dust across multiple wavelengths and angles, surveys at 440 and 880 nm can be used to characterize atmospheric dust within and above the crater. In addition, Rover Environmental Monitoring Station (REMS) on MSL provides downward radiation flux from 250 nm (UVD) to 340 nm (UVA), which would further constrain aerosol properties. The dust, which is not spherical and likely contains irregular particles, can be modeled using randomly oriented triaxial ellipsoids with predetermined microphysical optical properties and fit to sky survey observations to retrieve an effective radius. This work provides a discussion on the constraints of particle size distribution using REMS measurements as well as shape of the particle in Gale crater in comparison to Mastcam at the specified wavelengths.
