资源环境科技发展态势分析平台

Mars' atmosphere typically supports dust aerosol with an effective radius near 1.5 mu m, varying from similar to 1 mu m during low dust times near northern summer solstice to similar to 2 mu m during higher dust times in southern spring and summer. After global dust events, size variations outside this range have not previously been observed. We report on imaging and spectral observations by the Curiosity rover through the 2018 global dust event. These observations show that the dust effective radius was seasonally normal prior to the local onset of increased opacity, increased rapidly above 4 mu m with increasing opacity, remained above 3 mu m over a period of similar to 50 Martian solar days, then returned to seasonal values before the opacity did so. This demonstrates lifting and regional-scale transport of a dust population similar to 3 times the size of typical dust aerosol.

Plain Language Summary During the global dust storm of 2018, the Curiosity rover measured the variation of atmospheric dust over time. During the onset of the dust storm, typical Martian dust was enhanced by much larger particles that were freshly lifted off the surface in distant storms and then carried to the rover site at Gale crater. The larger dust particles persisted for weeks, but fell out of the atmosphere faster than the typical dust as normal conditions were restored.