CLIMATIC ABRUPT CHANGE IN THE NORTHERN HEMISPHERE FOR 1920s AND 1950s

In recent years,a large number of papers on the climatic sudden change have been presented.From the viewpoint of climatic sudden change,two methods of studying climatic sudden change are applied in this paper.The Northern Hemisphere land temperature(NHLT) during 1851-1984,China temperature(CT) during 1873-1990 and the Northern Hemisphere sea-level pressure(NHSLP) at each grid point during 1899-1987 are analyzed by the moving T-test.Theresults show that there exist two climatic sudden changes in the 1920s and the 1950s during the past 100 years,and then features of circulation for the two sudden changes are discussed by the NHSLP data.