Global structure and seasonal variations of the migrating 6-h tide observed by SABER/TIMED  

作　　者：LIU MoHan XU JiYao YUE Jia JIANG GuoYing 

机构地区：[1]State Key Laboratory of Space Weather, Center for Space Science and Applied Research,Chinese Academy of Sciences [2]College of Earth Science, University of Chinese Academy of Sciences [3]Center for Atmospheric Science, Hampton University

出　　处：《Science China Earth Sciences》2015年第7期1216-1227,共12页中国科学（地球科学英文版）

基　　金：supported by the Chinese Academy of Sciences(Grant No.KZZD-EW-01-2);the National Natural Science Foundation of China(Grant Nos.41331069,41274153);the National Basic Research Program of China(Grant No.2011CB811405);the Specialized Research Fund for State Key Laboratories of China;performed by Numerical Forecast Modelling R&D and VR System of State Key Lab.of Space Weather and Special HPC workstand of Chinese Meridian Project

摘　　要：Ten years of SABER/TIMED temperature data are used to analyze the global structure and seasonal variations of the migrating 6-h tide from the stratosphere to the lower thermosphere. The amplitudes of the migrating 6-h tide increase with altitudes. In the stratosphere, the migrating 6-h tide peaks around 35°N/S. The climatologically annual mean of the migrating 6-h tide clearly shows the manifestation of the(4, 6) Hough mode between 70 and 90 km that peaks at the equator and near 35°N/S. Above 90 km, the 6-h tide shows more than one Hough mode with the(4, 6) mode being the dominant one. The migrating 6-h tide is stronger in the southern hemisphere. Annual, semiannual, 4-, and 3-month oscillations are the four dominant seasonal variations of the tidal amplitude. In the stratosphere and stratopause, the spring enhancement of the 6-h tide at middle latitudes is the most conspicuous feature. From the mesosphere to the lower thermosphere, the tidal amplitude at low latitudes is gradually in the scale of that at middle latitudes and exhibits different temporal variations at different altitudes and latitudes. Both ozone heating in the stratosphere and the background atmosphere probably affect the generation and the seasonal variations of the migrating 6-h tide. In addition, the non-linear interaction between different tidal harmonics is another possible mechanism.Ten years of SABER/TIMED temperature data are used to analyze the global structure and seasonal variations of the migrating 6-h tide from the stratosphere to the lower thermosphere. The amplitudes of the migrating 6-h tide increase with altitudes. In the stratosphere, the migrating 6-h tide peaks around 35°N/S. The climatologically annual mean of the migrating 6-h tide clearly shows the manifestation of the（4, 6） Hough mode between 70 and 90 km that peaks at the equator and near 35°N/S. Above 90 km, the 6-h tide shows more than one Hough mode with the（4, 6） mode being the dominant one. The migrating 6-h tide is stronger in the southern hemisphere. Annual, semiannual, 4-, and 3-month oscillations are the four dominant seasonal variations of the tidal amplitude. In the stratosphere and stratopause, the spring enhancement of the 6-h tide at middle latitudes is the most conspicuous feature. From the mesosphere to the lower thermosphere, the tidal amplitude at low latitudes is gradually in the scale of that at middle latitudes and exhibits different temporal variations at different altitudes and latitudes. Both ozone heating in the stratosphere and the background atmosphere probably affect the generation and the seasonal variations of the migrating 6-h tide. In addition, the non-linear interaction between different tidal harmonics is another possible mechanism.

关 键 词：migrating tide global structure seasonal variations non-linear interaction bispectral analysis 

分 类 号：P434[天文地球—大气科学及气象学]