2.6 Ma BP前后亚洲季风系统的重组  

REORGANIZATION OF THE ASIAN MONSOON SYSTEM AT ABOUT 2.6 Ma AGO

作　　者：王建[1] 刘泽纯[1] 陈晔[1] 黄巧华[1] 陈霞[1] 

机构地区：[1]南京师范大学地理科学学院,南京210097

出　　处：《古地理学报》2000年第2期73-83,共11页Journal of Palaeogeography：Chinese Edition

基　　金：国家重点基础研究专项 (KZ - 95 1-A1- 2 0 4)资助

摘　　要：根据数值模拟的结果和中国区域环境分异与演化的地质记录 ,对 2 .6MaBP前后季风系统的调整进行了分析。结果发现 ,在 2 .6MaBP前后 ,亚洲季风明显增强 ,不仅冬季风明显增强 ,而且夏季风也明显增强 ;冬季风 (东亚冬季风 )在中国北方的盛行风向由偏西风转变为偏北风 ;冬季风 (东亚冬季风 )的影响范围明显扩大 ,由中国的西北、华北、东北地区逐步扩大到华中、华东与华南地区 ;由于受青藏高原的阻挡 ,热带西南季风对青藏高原北部及西北地区的直接影响大大减弱。这是青藏高原达到了一个重要的临界高度 (可能是 2 0 0 0m)In this paper, the changes of the Asian monsoon system at about 2.6 Ma ago are discussed based on atmospheric simulations and analysis of the geological records. The results show that the Asian monsoon system reorganized at about 2.6 Ma ago. At that time, both winter and summer monsoons being strengthened obviously and the direction of the winter monsoon in North China changed from North West West to North West North. In China, the area influenced by the East Asian monsoon increased, but the area influenced by Indian monsoon decreased. This is attributed to the uplifting of the Qinghai—Xizang Plateau and the southwestward migration of the center of the Asian Low. At some time of the Pliocene, the Tropical Southwest Monsoon had spreaded onto the Qinghai—Xizang region and has influenced areas over the North China and Northwest China. However, after 2.6 Ma BP, the effects of the Tropical Southwest Monsoon on Northwest China and the Northern part of the Qinghai—Xizang Plateau has decreased again. All these suggest that the Qinghai—Xizang Plateau perhaps reached about 2000 meter elevation above sea level at about 2.6 Ma BP.

关 键 词：亚洲 季风 青藏高原 环境变迁 气候变化 古地理 古气侯 

分 类 号：P531[天文地球—古生物学与地层学] P532[天文地球—地质学]