Spatial and Temporal Characteristics of Air Temperature over China in Spring Under the Background of Global Warming
DONG Lili;LI Qingquan;DING Yihui;Collaborative Innovation Centre on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science and Technology;Laboratory for Climate Studies of China Meteorological Administration,National Climate Centre;College of Atmospheric Science,Nanjing University of Information Science and Technology;
The climatological characteristics of seasonal,monthly and pentad mean air temperatures in the springs of 1981—2010 are analyzed and compared with those in the springs of 1951—1980 by using the daily air temperatures from observing stations of China and the monthly NCEP/NCAR atmospheric reanalysis data of the United States.The variation characteristics of air temperature and seasonal process in spring after 1980 s are also investigated.The possible causes for temperature change in spring are preliminarily discussed.The results show that except the Southwest China,most regions of China experience warming temperature in spring and the situation of temperature "increase-decrease" is presented from Northeast to Southwest after 1980 s.The air temperature rises by 0—1℃ in most regions of China except some parts of Southwest China in March,April and May.The seasonal process from March to May speeds up in the region to the south of Yangtze River and the eastern part of Southwest China,while it slows down in northeast China,the southern part of Southwest China and the northern part of Northwest China.The seasonal process in Inner Mongolia and the southern part of South China goes from fast to slow.On the whole,under the background of global warming,the onset and end dates of spring become earlier in East China,while the change is indistinct in West China.Compared with the condition in 1951—1980,the Ural blocking high and East Asian trough have weakened,while the zonal circulation over Asia in the middle and high latitudes,the subtropical high in western Pacific Ocean,and the subtropical westerly jet over East Asia have strengthened since 1980 s.Those are disadvantageous to the influence of cold air from polar region and high latitude areas in the Northern Hemisphere on the climate of China.Therefore,temperatures are high over most of China,especially Northeast China in spring.However,the strengthen of the middle east jet and the southward of the East Asian jet are in favor of the cold air from the central-eastern part of Europe influencing Southwest China and resulting in low air temperature there.In the meantime,the weakened southern branch trough goes against the warm and wet flows from the Indian Ocean and Bay of Bengal influencing the Southwest China,which easily results in low temperature in these areas.
【Fund】： 国家重点基础研究发展计划(973计划)(2013CB430202);; 国家重大科学研究计划(2012CB955203);; 公益性行业(气象)科研专项(GYHY201306021;GYHY 201406018);; 国家自然科学基金项目(41175065);; 气象行业标准项目(2200513)共同资助
【CateGory Index】： P423.3
【CateGory Index】： P423.3