Abstract:

Based on daily minimum and maximum temperature data in 11 meteorological stations obtained in the period from 1961 to 2005 over Sanjiangyuan region,the spatial and temporal characteristics of climate extremes were studied.The main results are summarized as follows:The trends for the annual number of warm days ( 26 d/10 a) and warm nights (44 d/10 a) are on the rise,while decreasing trends are found in the number of cold days (41 d/10 a) and cold nights (85 d/10 a);The changing trends of annual minimum temperature (042℃/10 a) is higher than that of maximum temperature(029℃/10 a);The increasing number of warm days and warm nights mainly occurs in winter and summer,while the decreasing number of cold days and cold nights occurs in spring and fall,and the trend of cold nights decreases significantly;The change in extreme in the source regions of the Yangtze River is more sensitive to the climate warming compared with the other two source regions.

Key words: Sanjiangyuan region, climate extremes, maximum and minimum temperature