The terraced thermal contrast among the Tibetan Plateau,the East Asian plain and the western North Pacific, and its impacts on the seasonal transition of East Asian Climate
- 作者：祁莉何金海王玉清
- 会议时间：2014-11-03
- 关键词：terraced thermal contrast ; year-round southerly ; Tibetan Plateau ; East Asian plain ; western North Pacific
- 作者单位：祁莉,何金海(南京信息工程大学,大气科学学院,南京210044)王玉清(University of Hawaii at Manoa,International Pacific Research Center and Department of Meteorology,Hawaii H1 96822,USA)
- 会议名称：第31届中国气象学会年会
- 会议地点：北京
- 主办单位：中国气象学会
- 语种：chi
- 分类号：P4;P7
摘要
The heating sources over the Tibetan Plateau (TP), the East Asian plain, and the western North Pacific (WNP) form a terraced thermal contract in the west-east direction.Over East Asia and the WNP, this zonal thermal contrast contributes as high as 45% to the seasonal variance based on the EOF analysis, and exerts a significant impact on the seasonal transition of the East Asian climate through the enhancement of the year-round southerly to the southeast of the TP in late March and early April.This effect is investigated in this study using a high-resolution regional atmospheric model by doubling the surface sensible heat flux, respectively, over the TP,the East Asian plain, and the WNP in three sensitivity experiments.Comparisons among the experiments reveal that doubling the surface sessile heat flux over the WNP has little upstream response over East Asia.The increased zonal thermal contrast between the TP and the East Asian plain due to doubled heat flux over the TP would induce anomalous northerly over the region with year-round southerly to the southeast of the TP, and weaken its seasonal enhancement.Doubling the surface sensible heat flux over the East Asian plain decreases the zonal thermal contrast and leads to southerly anomaly over the region with year-round southerly to the southeast of the TP and South China, which is favorable for the enhancement of the year-round southerly and its eastward extension.