Superrotation of the upper atmosphere.
Superrotation of the upper atmosphere.
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高层大气的超自转。
DOI：
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发表时间：
1972
期刊：
影响因子：
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通讯作者：
H. Rishbeth
中科院分区：
文献类型：
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作者：
H. Rishbeth
若干年前，D. G. 金 - 黑尔从人造卫星轨道倾角的微小变化中发现，高层大气的旋转速度比地球快约20%。本文概述了为解释这种所谓的“超旋转”而提出的几种理论。一些理论将其解释为热层中已知存在的水平压力变化的结果。其他理论将其归因于电离层或磁层运动对中性空气的反作用。另一组理论从热层中的热驱动不稳定性或振荡的角度来解释超旋转。目前还无法明确选择一种对超旋转的“正确”解释，但目前以下因素似乎可能是造成超旋转的原因：地转风、风产生的极化场对离子拖曳的日调制、与磁亚暴相关的电场驱动的离子拖曳、“移动火焰”现象以及大气波从较低层携带的向东动量的沉积。
Some years ago D. G. King-Hele discovered, from small changes in the orbital inclination of artificial satellites, that the upper atmosphere rotates about 20% faster than the earth. This article outlines several theories that have been advanced to explain this so-called ‘superrotation.’ Some theories explain it as a consequence of the horizontal pressure variations that are known to exist in the thermosphere. Other theories attribute it to ionospheric or magnetospheric motions that react on the neutral air. Another group of theories treats superrotation in terms of thermally driven instabilities or oscillations in the thermosphere. It is not yet possible to make a clear choice of a ‘correct’ explanation of superrotation, but at present the following appear to be possible contributory causes: geostrophic winds, diurnal modulation of ion drag by wind-produced polarization fields, ion drag driven by electric fields associated with magnetic substorms, the ‘moving flame’ phenomenon, and deposition by atmospheric waves of eastward momentum carried from lower levels.