Publisher Correction: Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter.
Publisher Correction: Martian dust storm impact on atmospheric H2O and D/H observed by ExoMars Trace Gas Orbiter.
复制标题
出版商更正：ExoMars 微量气体轨道飞行器观测到的火星沙尘暴对大气 H2O 和 D/H 的影响。
DOI：
10.1038/s41586-019-1163-x
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发表时间：
2019
期刊：
影响因子：
64.8
通讯作者：
Vandaele AC
中科院分区：
文献类型：
--
作者：
Vandaele AC
火星上的全球性沙尘暴很少见，但可以影响火星大气数月。它们会导致大气动力学的变化和大气的膨胀，这主要是由于灰尘的太阳加热所致。反过来，大气动力学的变化会影响大气水蒸气的分布，对火星上的大气光化学和气候具有潜在影响。最近对沙尘暴条件下火星大气中水蒸气丰度的观测表明，高空大气水蒸气增加，在北部高纬度地区更为明显，而低纬度地区水柱减少。在这里，我们展示了全球沙尘暴爆发时灰尘、水和半重水 (HDO) 的同步高分辨率测量结果，这些测量结果是由 ExoMars 痕量气体轨道飞行器上的 NOMAD 和 ACS 仪器获得的。我们报告了从行星边界层到 80 公里高度的 HDO/H2O 比率 (D/H) 的垂直分布。我们的研究结果表明，在沙尘暴爆发之前，HDO 丰度在 40 公里以上的海拔地区已降至可检测水平以下。 HDO 的减少与水冰云的出现同时发生。风暴期间，在 40 至 80 公里高度之间观察到 H2O 和 HDO 丰度增加。我们认为，丰度的增加可能是沙尘暴期间气温升高的结果，导致大气环流增强，并阻止了冰云的形成，这可能会通过重力下降和随后的冰晶升华将水蒸气限制在较低的高度。在沙尘暴发展的几天内，观察到的 H2O 和 HDO 丰度发生了变化，这表明沙尘暴对火星大气的快速影响。
Global dust storms on Mars are rare,but can affect the Martian atmosphere for several months. They can cause changes in atmospheric dynamics and inflation of the atmosphere, primarily owing to solar heating of the dust. In turn, changes in atmospheric dynamics can affect the distribution of atmospheric water vapour, with potential implications for the atmospheric photochemistry and climate on Mars. Recent observations of the water vapour abundance in the Martian atmosphere during dust storm conditions revealed a high-altitude increase in atmospheric water vapour that was more pronounced at high northern latitudes,, as well as a decrease in the water column at low latitudes,. Here we present concurrent, high-resolution measurements of dust, water and semiheavy water (HDO) at the onset of a global dust storm, obtained by the NOMAD and ACS instruments onboard the ExoMars Trace Gas Orbiter. We report the vertical distribution of the HDO/H2O ratio (D/H) from the planetary boundary layer up to an altitude of 80 kilometres. Our findings suggest that before the onset of the dust storm, HDO abundances were reduced to levels below detectability at altitudes above 40 kilometres. This decrease in HDO coincided with the presence of water-ice clouds. During the storm, an increase in the abundance of H2O and HDO was observed at altitudes between 40 and 80 kilometres. We propose that these increased abundances may be the result of warmer temperatures during the dust storm causing stronger atmospheric circulation and preventing ice cloud formation, which may confine water vapour to lower altitudes through gravitational fall and subsequent sublimation of ice crystals. The observed changes in H2O and HDO abundance occurred within a few days during the development of the dust storm, suggesting a fast impact of dust storms on the Martian atmosphere.