MULTI-SCALE ANALYSES OF SURFACE AIR TEMPERATURE VARIATIONS FOR THE NORTHERN HEMISPHERE AND CHINA DURING THE LAST ONE HUNDRED YEARS^*

Using multi-resolution theory of wavelet analysis,this paper studies the multi-scale structure of surface air temperature variations for the Northern Hemisphere and China during the last one hundred years.The results show that the climatic variations for the Northern Hemisphere can be described as 3 hierarchies corresponding to the larger-scale changes.They are the cold period before 1919,the warm period from 1920 to 1978 and the warmer period after 1979.The larger-scale hierarchical changes obviously show qualities of climate jump.The years 1920 and 1979 are the jump points of climate change.The surface air temperature variations for China are not entirely analogous to the Northern Hemisphere,and the main contrasts are that China is in the cold period after 1955 and the jump point of warming is 1987.The surface air temperature variations for the Northern Hemisphere and China during the last one hundred years obviously show the hierarchical structure of multi-scale changes and the qualities of climate jump.