Cause of winter gravity wave spectrum saturation
This paper utilizes horizontal velocity measurements observed from 19 chaff rockets and nearly simultaneous temperature measurements collected from 19 falling sphere rockets to study the cause of winter gravity wave spectrum saturation. Results suggest that strong horizontal velocity shears larger than 0.04 s-1 are observed to be present at various heights near the winter mesopause. On one single chaff rocket flight, an extremely
strong horizontal velocity shear as high as 0.33 s-1 is observed at 87.4 km and is believed to be the strongest value ever measured in the mesosphere. These strong horizontal velocity shears, together with Brunt-V(a)is(a)l(a) frequency squared obtained from the temperature profile, act collectively to yield two dynamical instability regions of Richardson number smaller than 1/4, suggesting that the saturated gravity wave spectrum observed by the chaff rockets in winter is a result of dynamical instability.
作 者：
WU Yongfu XU Jiyao
作者单位：
Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080, China
刊 名：
中国科学D辑（英文版） SCI
英文刊名：
SCIENCE IN CHINA SERIES D (EARTH SCIENCES)
年，卷(期)：
200548(10)
分类号：
P3
关键词：
winter spectrum strong shear dynamical instability spectrum saturation
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