摘要
文章利用气象资料揭示在印度半岛南部和北部，南亚季风降水变化在10年尺度以上呈翘翘板变化形式；利用更长的季风降水资料，即300年的喜马拉雅山达索普冰芯降水记录和印度半岛南部石笋降水记录，发现印度南部和喜马拉雅山季风降水呈双极振荡行为。自1700年以来，喜马拉雅山，即印度北部（或印度半岛南部）季风降水经历了1700～1764年期间的减小（或增加）趋势，1764～1876年期间的增大（或减小）趋势，1876～2000年期间的减小（或增加）趋势。同时，发现印度半岛南部的季风降水同北半球温度变化具有相同的变化特征，而喜马拉雅山季风降水同北半球温度变化具有相反的变化特征。南亚季风降水的这种南北翘翘板变化形式，与跨赤道气流有密切的联系。
A north-south spatial reversal of monsoon rainfall in Indian subcontinent has been identified. This dipole-like pattern displays an evidence of century variability with two turning points occurred around 1764 and 1876. The 1764 point represents a shift in monsoon rainfall in Northern India from decreasing to increasing while the 1876 point is from increasing to decreasing. On the contrary, in Southern Indian the 1764 turning point indicates a shift in monsoon rainfall from increasing to decreasing while the 1876 point from decreasing to increasing. The identification of this spatial reversal clarifies the former confusion existed between Indian monsoon rainfall and global warming. Our results show that the gross features of the monsoon rainfall in Southern India （or Northern India） are similar （or reverse） to the Northern Hemisphere temperature on centennial time scale over the past 300- year, which implies that the monsoon rainfall in Southern India （or Northern India） will increase （or decrease） during the coming century as greenhouse gas concentrations continue to rise.
We inferred that the changes in the Northern Hemisphere temperature might have caused the variation of the cross equatorial flow that is responsible for the dipole-like monsoon rainfall variability. However, the mechanism of monsoon is so complicated that there are still many aspects need to be understood. For example, does the dipole in the tropical Indian Ocean connect with the dipole-like mode of the Arabian Sea branch and the Bay of Bengal branch of the southwest monsoon circulation？ We hope that this study would provide a new insight into the study of southwest monsoon.
出处
《第四纪研究》
CAS
CSCD
北大核心
2006年第2期192-197,共6页
Quaternary Sciences
基金
国家自然科学基金人才项目创新研究群体科学基金项目(批准号:40121101)
国家自然科学基金重大研究项目(批准号:90102005)
国家科学技术部基础研究重大项目研究专项项目(批准号:2005CB422004)资助
关键词
南亚季风降水
喜马拉雅山
印度半岛南部
Indian monsoon rainfall, Himalayas, Southern Indian subcontinent
