The Leading Mode of Indian Ocean SST and Its Impacts on Asian Summer Monsoon
  • 【摘要】

    The Indian Ocean (IO) sea surface temperature (SST) was analyzed by using empirical orthogonal function (EOF), and the leading mode of Indian Ocean (LMIO) SST was extracted. The major spatial and temp... 展开>>The Indian Ocean (IO) sea surface temperature (SST) was analyzed by using empirical orthogonal function (EOF), and the leading mode of Indian Ocean (LMIO) SST was extracted. The major spatial and temporal characters of LMIO were discussed, and the relationships between LMIO with Indian summer monsoon (ISM) and with China summer rainfalls (CSR) were investigated, then the impacts of LMIO on Asian summer monsoon (ASM) circulation were explored. Some notable results are obtained: The significant evolutional characters of LMIO are the consistent warming trend of almost the whole IO basin,the distinctive quasi-3- and quasi-ll-yr oscillations and remarkably interdecadal warming in 1976/1977 and1997/1998, respectively. The LMIO impaired the lower level circulation of ISM and was closely related with the climate trend of CSR. It was associated with the weakening of South Asian high, the easterly winds south of the Tibetan Plateau, and the cross-equatorial flows over 10°-20°N, 40°-110°E at the upper level; with the strengthening of Somali cross-equatorial jet but the weakening of the circulation of ISM in the sector of India, the strengthening of south wind over the middle and lower reaches of Yangtze River and South China but the weakening of southwesterly winds over North China at lower level and with the increasing of surface pressure over the Asian Continent. Changes in the moisture flux transports integrated vertically over the whole troposphere associated with LMIO are similar to those in the lower level circulation. To sum up, the significant SST increasing trend of IO basin was one of the important causes for weakening of the ASM circulation and the southwards shifting of China summer rainband. 收起<<

  • 【作者】

  • 【作者单位】

    Laboratory for Climate Studies of China Meteorological Administration/Laboratory for Climate Studies of China Meteorological Administration/Group of Meteorological Audio and Video Information/Bureau of Hydrology

  • 【刊期】

    气象学报(英文版) SCI 2008年1期

  • 【关键词】

    leading mode of Indian Ocean (LMIO) SST  China summer rainfalls (CSR)  Indian summermonsoon (ISM)  Asian summer monsoon (ASM)  water vapor transport 

  • 【基金项目】

    国家重点基础研究发展计划(973计划) 国家自然科学基金