Hydrogen escape from Mars is driven by seasonal and dust storm transport of water

doi:10.1126/science.aba5229

GSTDTAP > 气候变化

DOI	10.1126/science.aba5229
	Hydrogen escape from Mars is driven by seasonal and dust storm transport of water
	Shane W. Stone; Roger V. Yelle; Mehdi Benna; Daniel Y. Lo; Meredith K. Elrod; Paul R. Mahaffy
	2020-11-13
发表期刊	Science
出版年	2020
英文摘要	Mars was once a wet planet, but it has lost most of its water through reactions that produce hydrogen, which escapes from the upper atmosphere into space. Stone et al. used data from the Mars Atmosphere and Volatile Evolution spacecraft to study how water is transported to the upper atmosphere and converted to hydrogen. They found that water can reach higher altitudes than previously thought, especially during global or regional dust storms. Photochemical modeling shows that this process dominates the current loss of water from Mars and influenced the evolution of its climate. Science , this issue p. [824][1] Mars has lost most of its once-abundant water to space, leaving the planet cold and dry. In standard models, molecular hydrogen produced from water in the lower atmosphere diffuses into the upper atmosphere where it is dissociated, producing atomic hydrogen, which is lost. Using observations from the Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution spacecraft, we demonstrate that water is instead transported directly to the upper atmosphere, then dissociated by ions to produce atomic hydrogen. The water abundance in the upper atmosphere varied seasonally, peaking in southern summer, and surged during dust storms, including the 2018 global dust storm. We calculate that this transport of water dominates the present-day loss of atomic hydrogen to space and influenced the evolution of Mars’ climate. [1]: /lookup/doi/10.1126/science.aba5229
领域	气候变化 ; 资源环境
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文献类型	期刊论文
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/304137
专题	气候变化资源环境科学
推荐引用方式 GB/T 7714	Shane W. Stone,Roger V. Yelle,Mehdi Benna,et al. Hydrogen escape from Mars is driven by seasonal and dust storm transport of water[J]. Science,2020.
APA	Shane W. Stone,Roger V. Yelle,Mehdi Benna,Daniel Y. Lo,Meredith K. Elrod,&Paul R. Mahaffy.(2020).Hydrogen escape from Mars is driven by seasonal and dust storm transport of water.Science.
MLA	Shane W. Stone,et al."Hydrogen escape from Mars is driven by seasonal and dust storm transport of water".Science (2020).