Trends of temperature and precipitation variation in the Yangtze River Delta from 1961 to 2006.

Based on the meteorological data of 84 stations in the Yangtze River delta from 1961 to 2006,the basic features of temporal and spatial changes of temperature and precipitation are investigated.Results show that the annual mean temperature increased significantly during the past 46 years.Winter,spring and autumn mean temperature all increased significantly,and the temperature increasing rate in winter is the biggest.The areas with significant temperature increase coincide with the main urban areas.The annual minimum temperature shows an evident increasing trend while the frequency of extreme low temperature events decreased.In most regions,the maximum temperature increased significantly,especially in the mega-city regions.The annual precipitation did not show any significant trend,but the seasonal distribution of the precipitation exhibits significant changes.The precipitation increased in both winter and summer while decreased in autumn.However,no significant trend was detected in spring.