热带气象学报2011,Vol.27Issue(4):560-568,9.DOI:10.3969/j.issn.1004-4965.2011.04.013
夏季海洋性大陆区域O LR年际变动与中国长江中上游旱涝的关系
VARIATIONS OF OLR IN MARITIME CONTINENT REGIONS IN ASSOCIATION WITH DROUGHTS AND FLOODS IN THE UPPER AND MIDDLE REACHES OF YANGTZE RIVER OF CHINA IN BOREAL SUMMER
摘要
Abstract
Using the monthly mean data from NECP, GISST dateset, along with station rainfall data in China from 1979 to 2007, we have investigated the relationships between Outgoing Long-wave Radiation (OLR) and the summertime rainfall in China by performing the SVD analysis. Our results show that the convective activities around the Bay of Bengal, monsoon trough in South China Sea, the South Pacific convergence zone (SPCZ), and the Indonesian Islands and as well as the surrounding waters are significantly correlated with the summer time rainfall in the upper middle reaches of Yangtze River. When the OLR is higher (lower) than normal over the Bay of Bengal, monsoon trough region, and the South Pacific convergence zone(SPCZ), and lower(higher) than normal over the south Indian Ocean and around Indonesian Islands, the precipitation in the upper and middle reaches of Yangtze River will be significantly more (less) than normal. An index Imcolr as derived from OLR is defined in Maritime Continent, which associates with rainfall in the upper and middle reaches of Yangtze River. Composite differences of several quantities between high index IMCOLR and low index years show that the anomalous increases in the net radiation of air column and the thermal fluxes at sea surface around Indonesian Islands facilitate stronger convections and henceforth less OLR there. This anomalous heating forces the atmosphere to respond to weaken the surface thermal fluxes in the Bay of Bengal, leading to weaker convections, and henceforth more OLR there. It is found that /mcolr is well correlated with SSTA showing a triple like structure in tropical Indo-Pacific. These anomalous thermal forcings lead to anomalous response of atmosphere lower troposphere, resulting a P-J like pattern and henceforth affecting the anomalous precipitation in the upper and middle reaches of Yangtze River.关键词
气候学/向外长波辐射/奇异值分解/热带海洋性大陆/长江中上游/夏季Key words
Climatology/ outgoing long-wave radiation(OLR)/ Singular value decomposition/itime Continent/ upper and middle reaches of Yangtze River/ boreal summer分类
天文与地球科学引用本文复制引用
宋大伟,管兆勇,唐卫亚..夏季海洋性大陆区域O LR年际变动与中国长江中上游旱涝的关系[J].热带气象学报,2011,27(4):560-568,9.基金项目
国家重点基础研究发展计划项目973课题(2006CB403602)资助 (2006CB403602)