Main Submonthly Timescals of Northern and Southern Hemispheres Annual Modes
南、北半球环状模月内活动的主要时间尺度

Based on the conception of "Annular Belts of Action (ABAs)" ,characteristics of the seasonal variation and main submonthly timescales of Northern and Southern hemispheres annular modes (SAM and NAM) are studied in this paper using NCEP/NCAR reanalysis daily data. The results show that NAM is strong in winter and weak in summer while SAM's intensity has semi-annual cycle. Furthermore,power spectrum analysis is applied year by year to detect the main submonthly timescals of anular modes,the result shows that ...