The Study On Climate Change And Feature In Global Land Precipitation Field From 1948 To 2001 During September To November

The paper comprehensively analyzed the data of global land monthly data PREC/L created by Chen et al. (2001) from 1948 to 2001.Using wavelet analysis and calculating trend index to analyze the feature of period and trend of global land precipitation records from September to November and the data of each month. The results show that there is a obvious 2-7 years cycle in consistence with the ENSO cycle as well as the decadal cycle. Except for the weak decreasing of October, the time series of global precipitation during September to November and the other two months are of strongly decreasing. It also points out that the trend variation of the rainfall is possibly caused by the global wanning and ENSO events.A method is brought forward to identify the dry and flood years for precipitation during September to November in global and large scale areas. The way to test the method is also given. We have used the method to identify the global dry and flood years for precipitation during September to November from 1948 to 2001. The results show that there is apparent relation between the global dry (flood) years and warm (cold) events. The distribution of the global dry and flood years takes on decadal character.We also identify the dry and flood years for precipitation during September to November in north and south hemisphere. There is a obviously positive correlation between the north hemisphere dry (flood) years and the south hemisphere dry (flood) years. And it is also happened between north hemisphere and globe.Further more, the dry and flood years for precipitation during September to November in Asia-Europe, Africa, Australia, North America, South America and austral pole are identified respectively. We discussed the possible relation of the dry and flood years among the continents.The relation between the dry and flood years for precipitation during September to November in global and large scale areas and the anomaly of sea surface temperature of key ocean are preliminary investigated.