Large Dust Aerosol Sizes Seen During the 2018 Martian Global Dust Event by the Curiosity Rover
Large Dust Aerosol Sizes Seen During the 2018 Martian Global Dust Event by the Curiosity Rover
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DOI：
10.1029/2019gl084407
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发表时间：
2019-08-28
影响因子：
5.2
通讯作者：
Jacob, S.
中科院分区：
文献类型：
--
作者：
Lemmon, M. T.;Guzewich, S. D.;Jacob, S.
火星大气层通常支持有效半径接近1.5 μ m的尘埃气溶胶，从北方夏至附近低尘时期的1 μ m到南方春季和夏季高尘时期的2 μ m。在全球沙尘事件之后，以前没有观察到这个范围之外的大小变化。我们通过2018年全球尘埃事件报告了Currency漫游者的成像和光谱观测。这些观测结果表明，尘埃的有效半径是季节性正常的地方发病之前增加不透明度，迅速增加到4 μ m以上的增加不透明度，保持在3 μ m以上的一段时间类似于50火星太阳日，然后返回到季节性值之前不透明度这样做。这证明了一个类似于3倍于典型沙尘气溶胶大小的沙尘群的抬升和区域尺度传输。简明语言摘要在2018年的全球沙尘暴期间，Currency火星车测量了大气沙尘随时间的变化。在沙尘暴爆发期间，典型的火星尘埃被更大的颗粒增强，这些颗粒在遥远的风暴中新鲜地从表面升起，然后被带到盖尔陨石坑的火星车站点。较大的尘埃颗粒持续了数周，但随着正常条件的恢复，比典型的尘埃更快地从大气中脱落。
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.