Determination of dust aerosol particle size at Gale Crater using REMS UVS and Mastcam measurements

摘要

We calculate the seasonal and interannual variation in dust aerosol particle size above Gale Crater during the first 1413Martian solar days (sols=24.6h) of the Mars Science Laboratory mission. Measurements of UV radiation made by the Rover Environmental Monitoring Station in combination with atmospheric opacities retrieved from the Mastcam instrument are used for the calculations. Our results indicate that the dust effective radius varies significantly with season, ranging from similar to 0.6 mu m during the low opacity season (L-s=60 degrees-140 degrees) to similar to 2 mu m during the high opacity season (L-s=180 degrees-360 degrees). Our results suggest that Gale Crater is affected by dust events of high aerosol content originated at various distances from it. Our results improve the accuracy of estimations of ultraviolet radiation fluxes at the Martian surface. Moreover, our results have important implications because the lifetime of suspended dust and its ability to nucleate clouds are affected by particle size.