DOI: 10.1038/ngeo2020
论文题名: Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency
作者: Robinson T.D. ; Catling D.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2014
卷: 7, 期: 1 起始页码: 12
结束页码: 15
语种: 英语
英文摘要: A minimum atmospheric temperature, or tropopause, occurs at a pressure of around 0.1 bar in the atmospheres of Earth, Titan, Jupiter, Saturn, Uranus and Neptune, despite great differences in atmospheric composition, gravity, internal heat and sunlight. In all of these bodies, the tropopause separates a stratosphere with a temperature profile that is controlled by the absorption of short-wave solar radiation, from a region below characterized by convection, weather and clouds. However, it is not obvious why the tropopause occurs at the specific pressure near 0.1 bar. Here we use a simple, physically based model to demonstrate that, at atmospheric pressures lower than 0.1 bar, transparency to thermal radiation allows short-wave heating to dominate, creating a stratosphere. At higher pressures, atmospheres become opaque to thermal radiation, causing temperatures to increase with depth and convection to ensue. A common dependence of infrared opacity on pressure, arising from the shared physics of molecular absorption, sets the 0.1 bar tropopause. We reason that a tropopause at a pressure of approximately 0.1 bar is characteristic of many thick atmospheres, including exoplanets and exomoons in our galaxy and beyond. Judicious use of this rule could help constrain the atmospheric structure, and thus the surface environments and habitability, of exoplanets. © 2014 Macmillan Publishers Limited. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/106424
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: NASA Ames Research Center, Moffett Field, CA 94035, United States; NASA Astrobiology Institute's Virtual Planetary Laboratory, University of Washington, Seattle,WA 98195, United States; University of Washington Astrobiology Program, University of Washington, Seattle, WA 98195, United States; Department of Earth and Space Sciences, University of Washington, Seattle,WA 98195, United States
Recommended Citation:
Robinson T.D.,Catling D.C.. Common 0.1 bar tropopause in thick atmospheres set by pressure-dependent infrared transparency[J]. Nature Geoscience,2014-01-01,7(1)