Opposite contributions of stationary and traveling planetary waves in the Northern Hemisphere winter middle atmosphere
Opposite contributions of stationary and traveling planetary waves in the Northern Hemisphere winter middle atmosphere
复制标题
北半球冬季中层大气中静止行星波和行行星波的相反贡献
DOI：
10.1029/2020jd034195
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
T. Hirooka
中科院分区：
文献类型：
--
作者：
K. Iwao;T. Hirooka
通过对宽带辐射辐射计(SABER)探测大气的卫星资料的分析，研究了行星波(PWS)对北半球冬季行星波(PW)活动强烈的中层大气平均气流的贡献。结果表明，月平均定常行星波(STPWs)对东风加速的贡献与高纬低层残留行星波(TRPWs)对西风加速的贡献相反。当中层出现东风时，由于不能在东风区传播，从对流层传播的短时低空急流在中低层消散，加速东风。另一方面，由于纬向气流不稳定加速西风，TRPWs在那里发展。中层的东风经常是由平流层发展的向西TRPWs的消散引起的，并将由这些相反的贡献维持10天以上。进一步的分析表明，发展在高纬度低中间层的TRPW可能是一个纬向波数为1的向东的TRPW，周期为10-40天。这种TRPW将通过消除中层PW耗散在东风区下方形成的暖温度异常而发展和向下传播，从而消除斜压不稳定。
This study investigates contributions of planetary waves (PWs) to the mean flow in the middle atmosphere during the Northern Hemisphere winter when PW activities are strong, by analyzing satellite data from Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). It is suggested that there would be opposite contributions between easterly acceleration by monthly mean stationary planetary waves (STPWs) and westerly acceleration by remaining traveling planetary waves (TRPWs) in the high‐latitude lower mesosphere. When easterly winds appear in the mesosphere, STPWs propagating from the troposphere dissipate in the lower mesosphere to accelerate easterly winds because STPWs could not propagate in easterly wind regions. On the other hand, TRPWs develop there due to the zonal flow instability to accelerate westerly winds. The easterly wind in the mesosphere is frequently triggered by dissipation of westward TRPWs developed in the stratosphere, and would be maintained by these opposite contributions for more than 10 days. Further analyses suggest that the TRPW developing in the high‐latitude lower mesosphere would be an eastward TRPW of zonal wavenumber 1 and a period of 10–40 days. This TRPW would develop and propagate downward to dismiss the baroclinic instability by eliminating warm temperature anomalies formed below the easterly wind region due to the PW dissipation in the mesosphere.