Variation Characteristics of Extreme Temperature Events in Changsha from 1951 to 2010

doi:10.3969/j.issn.1673-7148.2012.03.006

Abstract：Based on the highest and lowest temperature data in Changsha from 1951 to 2010, by u- sing the international common percentage threshold method which can determine the warm day, warm night, cold day and cold night, linear tendency estimation method and M-K mutations detection method, the temporal and spatial variation characteristics of extreme temperature events in Changsha during the past 60 years were analyzed. The research results indicated that the warm day and warm night increased with a rate of 3.48 d ·（10a） -1 and 3.06 d · （10a） -1, while the cold day and cold night decreased with a rate of -2.13 d· （10a） -1 and - 1.78 d · （10a） -1. The warming in daytime increased more than in night. It also indicated that the periodic characteristic was significant and the warm day, cold day and cold night had abrupt changes. The most significant increase of warm day was in fall, followed by in spring. The most significant increase of warm night was in summer, followed by in winter. The decrease of cold day or night happened most in spring and winter. All seasons were becoming warmer, especially in spring and winter. The most significant increase of warm day or night was in July, and the most signifi- cant decrease of cold day or night was in April and February.