关键词: 北美大陆, 欧亚大陆, 干湿变化, 冬季增温

Abstract: This study examined surface air temperature trends over global land in 1901-2009 using data (monthly precipitation and monthly mean surface air temperature) from Climatic Research Unit (CRU) at University of East Anglia. It is found that the warming trend was particularly enhanced in the winter seasons over semi-arid regions at mid-high-latitude areas. By analyzing the temporal and spatial characteristics of dry/wet variation at the surface of North America and Eurasia and the impact of enhanced winter warming upon the dry/wet variation, it is found that the south of North America was becoming wet weakly and Arctic Archipelago in Canada became wet apparently while the middle and west of North America was drier. In Eurasia, most of the continent became drier, especially in the south of West Europe, North China, Northeast China, the central-north and northeast of Mongolia and far east of Russia. But there was no clear trend of precipitation in North America and Eurasia during the winter seasons in 1950-2008, so the dry/wet variation was mainly affected by the change of temperature, especially in the places where winter warming was enhanced.

Key words: North America, Eurasia, dry/wet variation, winter warming