月内尺度南半球环状模对应的大气环流异常传播特征  

Propagation Characteristics of Atmospheric Circulation Anomalies of Sub-monthly Southern Hemisphere Annular Mode

作　　者：李晓峰[1] 李建平[1] 

机构地区：[1]中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室,北京100029

出　　处：《大气科学》2010年第6期1099-1113,共15页Chinese Journal of Atmospheric Sciences

基　　金：国家重点基础研究发展计划项目2010CB950400;国家自然科学基金资助项目40905040;中国科学院院知识创新工程重要方向项目KZCX2-YW-Q11-01

摘　　要：本文利用NCEP/NCAR逐日再分析资料,分析了南半球环状模(Southern Hemisphere Annular Mode,简称SAM)在月内时间尺度(sub-monthly timescales,5～30天)上相关环流的垂直和水平传播特征。结果表明,月内SAM对应的纬向风异常和温度异常具有明显自南极地区向南半球中纬度地区水平传播特征;在垂直方向上,纬向风异常为明显上传特征,温度异常则具有在极地和高纬度地区明显上升、低纬度地区下沉的特点。月内SAM对应的南半球中高纬度地区上传信号表明,在较短的月内时间尺度上,对流层信号可以突破对流层顶,上传达到平流层;而月内SAM对应的整层南传信号表明,南极地区环流变化超前于中高纬度地区,因此在1～3周的月内时间尺度上,极区信号可能对中高纬地区信号具有指示意义。The related horizontal and vertical propagation characteristics of the Southern Hemisphere Annular Mode（SAM）on the sub-monthly timescales（5-30 days）is studied by employing the NCEP/NCAR reanalysis daily data.The results show that the zonal mean zonal wind anomalies and temperature anomalies propagate horizontally from the Antarctic regions to the middle and high latitudes of the Southern Hemisphere;in the vertical direction,the zonal mean zonal wind anomalies mainly propagate upward,and the temperature anomalies propagate upward in the polar regions and propagate downward in the low latitudes.The characteristics of upward propagation of the sub-monthly SAM signals imply that the tropospheric SAM signals can propagate upward into the lower stratosphere on relative short timescales.And the northward propagation of the sub-monthly SAM signals suggests that the variation of circulation in the Antarctic region leads to the variations in the middle and high latitudes of the Southern Hemisphere.So,the Antarctic signals may have prediction skills to those in middle and high latitudes of the Southern Hemisphere on the timescales from one week to three weeks.

关 键 词：南半球环状模 月内时间尺度 水平传播 垂直传播 

分 类 号：P434[天文地球—大气科学及气象学]