摘要
利用欧洲中心ERA-40月平均再分析资料,分析了1958-2001年冬季欧亚中高纬陆面热力状况的变化特征,重点讨论了冬季陆面热力异常与中高纬大气环流的联系及其可能影响机制。结果表明:由于全球变暖的区域非均匀性,近年来冬季欧亚中高纬陆面增温趋势显著且增温幅度较大,中低纬陆面增温幅度相对偏小,陆面热力变化的经向非均匀性造成欧亚大陆中纬度区域(40°N-50°N附近)的陆面经向温度梯度在20世纪80年代初发生了显著的年代际减弱。由于陆面对大气的加热作用,导致蒙古高原至中国东北地区对流层低层大气经向温度梯度减小,从而使得对流层大气斜压性减弱,根据热成风原理,纬向风垂直切变减小,最终导致欧亚中高纬高空西风环流异常偏弱。
Based on ERA40 monthly reanalysis data,the features of the land surface thermal anomalies over the mid- high latitudes of the Eurasian Continent during 1958- 2001 were investigated,and the possible linkage between the land surface thermal anomalies and the atmospheric general circulation was further explored. Because of the global warming in recent years,the land surface temperature warming trend is more obvious and higher in the north of Lake Balkhash and Lake Baikal than the lower latitudes. Due to the inhomogeneously meridional land surface thermal changes,there is an apparent decadal weakening of the meridional land surface temperature gradient over the mid- latitude region of Eurasian Continent( around 40° N- 50° N) at the early 1980. Decreased meridional gradient of the surface soil temperature tends to decrease the meridional gradients of both the surface air temperature and the air temperature in the lower atmosphere. According to thermal wind theory,decreased meridional temperature gradient will result in the decrease of the atmospheric baroclinicity. Meanwhile,the gradient of lowlevel troposphere temperature,the vertical shear of zonal wind and zonal wind itself will be decreased.
出处
《高原气象》
CSCD
北大核心
2015年第6期1584-1592,共9页
Plateau Meteorology
基金
科技部公益性行业(气象)科研专项(GYHY201206017)
国家自然科学基金项目(41230422)
江苏省自然科学基金-杰出青年基金项目(BK20130047)
新世纪优秀人才支持计划
关键词
陆面热力异常
中高纬环流
经向温度梯度
垂直风切变
全球变暖
Land surface thermal anomalies
General circulation in the mid-high latitudes
Meridional temperature gradient
Vertical wind shear
Global warming
