Study On Spatial And Temporal Characteristics Of Climate Change In Jiangsu Province In Recent 45 Years

Based on observational datas of 62 meteorological stations from 1961 to 2005 and 15 solar radiation stations, using the methods of linear trend analysis, MK trend test, EOF analysis, abrupt change test and moving average, the spatial and temporal distributions and their trends for temperature, precipitation and global solar radiation in Jiangsu province are investigated . The conclusion can be drawn as follows: (1) The annual,spring,autumn and winter average temperature has an obvious decrease trend in the whole province especially in winter, which the jump points are around year of 1996,1996,1997 and 1989 respectively; The summer average temperature slightly increased generally, and some areas appear a decrease trend. With EOF method, we found the first typical field (whose contributing rate is 90% at least and distribution is positive)can indicate the main characteristics of annual and seasonal rainfall distributions and called it as synchronized in the whole area of the province. (2) The number of days with the 95th percentiles of daily maximum temperatures increased slightly, meanwhile, the number of days of the 5th percentiles of daily minimum temperatures decreased greatly; The number of days with maximum temperatures over 35℃increased slightly, and the frost days decreased significantly. (3) The annual, spring, summer precipitation in Jiangsu has no significant change trend, but autumn precipitation decreased significantly and winter precipitation which has jump time for about 1988 increased greatly; The first principal component exhibited all over the province is consistent indicating the drought or the flood in annual and seasonal precipitation by using the method of EOF. (4) The annual,spring,summer,winter precipitation days has no significant change trend, only a significant decrease trend for autumn precipitation days. (5) The extreme precipitation quantity and its frequency in summer appear a significant increase trend and the extreme precipitation intensity in autumn appears a decrease trend. (6) The global solar radiation has significantly decreased, especially in the seasons of summer and winter. All annual and summer global solar radiation catastrophe appeared in 1980.