Study of Climatic Type Change for Recent 50 Years in North China

By Using the data of homogenization observational data from 1961 to 2009 in North China and the Coburn climate classification,the climatic change trend and the climatic type of North China are investigated.The results showed that,from 1961 to 2009,the average annual temperature in North China ranges from 0.44℃/10y,the annual precipitation is decreasing,and the reduce amplitude is 9.3mm/10y.The spatial trend showed that,there is a warming trend in North China,and the most obvious parts is in central and eastern Inner Mongolia and south of Hebei Province,which is more than 0.6℃/10y.The annual average temperature of 0℃ and 5℃ has a more visible phenomenon of the northward movement in the 2000s than the 1960s,especially the central region of Inner Mongolia.North China in recent 50 years have a greater volatility in the 250mm rainfall line,mainly from Xilinguole to Hulunbeier region in northeastern Inner Mongolia.It has a more obvious eastward movement for recent 10 years,indicating that the precipitation decreased significantly.By using the Coburn climate classification method,the North China region presents a warm dry climate trend from 1961 to 2009,some sites from the non-dry-dry type to the arid-semi-arid climate types,mainly in central Inner Mongolia and northern Shanxi province,but the overall climate of North China region and climate type has no fundamental change.