摘要
利用1979—2011年NCEP/NCAR再分析资料、我国160个站降水和气温资料,分析欧亚大陆热力变化特征,其在冬季和春季的气候变率最明显,且南北区域呈反相差异。在此基础上,探讨1—3月欧亚大陆热力差异与中国降水异常的关系,欧亚大陆正(负)热力差异年,1—3月华南、西南至河套西部地区降水偏多(少)明显,后期夏季多雨带位于长江中下游地区(华南地区)。大气环流异常特征显示:1—3月欧亚大陆南北热力差异与同期北极涛动(AO)、东亚大槽、东亚高空急流等大尺度大气环流,以及后期东亚高空急流、南亚高压、低层季风风系异常的密切相关是欧亚大陆热力变化与中国降水联系的可能途径。
Seasonal changes of thermal differences between the sea and the land（land-sea thermal contrast） is a key influence factor to monsoon formation,strength change,onset and retreat.Land thermal condition significantly influences atmospheric circulation at high and low level,monsoon activities and climatic anomalies.Being the largest land of the world,effects of Eurasian continent on global climate are more complicated and important,especially considering the heat source seasonal changes of the Tibetan Plateau.Based on NCEP/NCAR reanalysis data and monthly data of 160 meteorological stations in China from1979 to 2011,the thermal characteristics over Eurasian continent are investigated.Results show that the climatic variability of surface air temperature（SAT） displays obvious difference in different regions and seasons.The SAT variability is significantly larger in south Eurasia than that in north Eurasia,and is the biggest in winter and the weakest in summer.Temporal and spatial characteristics of SAT over Eurasian continent from January to March are emphatically investigated,and it＇s found thermal changes are just opposite with positive（negative） anomalies in south Eurasia and negative（positive） anomalies in south Eurasia.According to the variation characteristics of temporal coefficient of the first empirical orthogonal function（EOF-PC1）,8 positive and 8 negative thermal contrast years are chosen,and the relationship between changes of the thermal variation over Eurasian continent and precipitation in China is further studied using methods of correlation and composite analysis.Results show that this thermal contrast is not only closely connected with precipitation in China from January to March,but also connected with the precipitation in the following summer.The thermal index is shown to be positively correlated with the accumulative pre-.cipitation in South China,Southwest China and middle reaches of the Huang River from January to March,and the rainfall amount of the middle and lower reaches
出处
《应用气象学报》
CSCD
北大核心
2016年第2期209-219,共11页
Journal of Applied Meteorological Science
基金
公益性行业(气象)科研专项(GYHY201206017)
国家重点基础研究发展计划(2013CB430202)
国家自然科学基金项目(41575097)
关键词
欧亚大陆
1-3月地面温度
中国降水
年际变化
Eurasia
surface air temperature for January-March
precipitation of China
inter-annual variability
