Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1038/NGEO2887 |
Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water | |
Chaffin, M. S.; Deighan, J.; Schneider, N. M.; Stewart, A. I. F. | |
2017-03-01 | |
发表期刊 | NATURE GEOSCIENCE |
ISSN | 1752-0894 |
EISSN | 1752-0908 |
出版年 | 2017 |
卷号 | 10期号:3 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | Atmospheric loss has controlled the history of Martian habitability, removing most of the planet's initial water through atomic hydrogen and oxygen escape from the upper atmosphere to space. In standard models, H and O escape in a stoichiometric 2:1 ratio because H reaches the upper atmosphere via long-lived molecular hydrogen, whose abundance is regulated by a photochemical feedback sensitive to atmospheric oxygen content. The relatively constant escape rates these models predict are inconsistent with known H escape variations of more than an order of magnitude on seasonal timescales, variation that requires escaping H to have a source other than H-2. The best candidate source is high-altitude water, detected by the Mars Express spacecraft in seasonally variable concentrations. Here we use a one-dimensional time-dependent photochemical model to show that the introduction of high-altitude water can produce a large increase in the H escape rate on a timescale of weeks, quantitatively linking these observations. This H escape pathway produces prompt H loss that is not immediately balanced by O escape, influencing the oxidation state of the atmosphere for millions of years. Martian atmospheric water loss may be dominated by escape via this pathway, which may therefore potentially control the planet's atmospheric chemistry. Our findings highlight the influence that seasonal atmospheric variability can have on planetary evolution. |
领域 | 地球科学 ; 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000395791400007 |
WOS关键词 | MARTIAN ATMOSPHERE ; IONOSPHERE ; SOLAR ; PHOTODISSOCIATION ; PHOTOCHEMISTRY ; VARIABILITY ; CHEMISTRY ; EVOLUTION ; EXOSPHERE ; CORONA |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/35054 |
专题 | 地球科学 气候变化 |
作者单位 | Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80303 USA |
推荐引用方式 GB/T 7714 | Chaffin, M. S.,Deighan, J.,Schneider, N. M.,et al. Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water[J]. NATURE GEOSCIENCE,2017,10(3). |
APA | Chaffin, M. S.,Deighan, J.,Schneider, N. M.,&Stewart, A. I. F..(2017).Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water.NATURE GEOSCIENCE,10(3). |
MLA | Chaffin, M. S.,et al."Elevated atmospheric escape of atomic hydrogen from Mars induced by high-altitude water".NATURE GEOSCIENCE 10.3(2017). |
条目包含的文件 | 条目无相关文件。 |
除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。
修改评论