FEATURES AND COMPARISONS OF THE QUASI-BIENNIAL VARIATIONS IN THE ASIA-PACIFIC MONSOON SUBSYSTEMS

The National Centers for Environmental Prediction (NCEP) reanalysis data Climate Diagnostics Center Merged Analysis of Precipitation (CMAP) results,and NOAA Extended Reconstructed Sea Surface Temperature (SST),have been utilized in this paper to study the quasi-biennial variations in Asia-Pacific monsoon subsystems and associated SST anomalies (SSTA) and wind anomalies. Four monsoon indices are computed fi,om NCEP/National Center for Atmospheric Research (NCAR) reanalysis to represent the South Asian monsoon (SAM),South China Sea summer monsoon (SCSSM),Western North Pacific monsoon (WNPM) and East Asian monsoon (EAM),respectively. The quasi-biennial periods are very significant in Asia-Pacific monsoons (as discovered by power spectrum analysis),and for SAM and EAM---with moderate effects by EI Ni(n)o-Southern Oscillation (ENSO)---the quasi-biennial periods are the most important factor. For SCSSM and WNPM (once again due to the effects of ENSO),the quasi-biennial periods are of secondary durations. There are obvious interdecadal variations in the quasi-biennial modes of the Asia-Pacific monsoon,so in the negative phase the biennial modes will not be significant or outstanding. The wind anomalies and SSTA associated with the biennial modes are very different in the SAM. WNPM and EAM regions. Since the WNPM and SCSSM are very similar in the biennial modes,they can be combined into one subsystem,called SCS/WNPM.

作 者： ZHENG Bin LI Chun-hui LIN Ai-lan GU De-jun   作者單位： Guangzhou Institute of Tropical and Marine Meteorology / Key Open I,aboratory for Tropical Monsoon, China Meteorological Administration,Guangzhou 510080 China  刊 名： 熱帶氣象學報(英文版)  英文刊名： JOURNAL OF TROPICAL METEOROLOGY  年，卷(期)： 2009 15(1)  分類號： P444  關(guān)鍵詞： Asia-Pacific monsoon   power spectrum   wave filtering   monsoon indices   quasi-biennial variation