Analysis of Extreme Weather Events in Beijing during 1951-2008

Based on the daily observation data during 1951-2008, the change of extreme weather events in Beijing are analyzed. Results show that: (1) The annual mean temperature, minimum temperature, and mist events show increasing trends of 0.39℃·(10 a) -1, 1.0 ℃·(10 a)-1, and 12.4 d·(10 a)-1 respectively. The maximum 24 h rainfall shows a decreasing trend of -10.8 mm·(10 a)-1, rain days, humidity, gale, and thunder storm decrease at different extent -1.90 d·(10 a)-1,-1.17% (10 a)-1,-2.64 d·(10 a)-1,and -1.24 d·(10 a)-1, sand and dust events show a decreasing trend of -9.39 d·(10 a)-1. The maximum temperature, the maximum rain intensity(60 min), and rainstorm, frost, fog, high temperature events have little change. (2) Rainstorm, high temperature, the maximum temperature, and sand and dust events have no remarkable periodicity. Thunder storm, frost, the minimum temperature, the maximum 24 h rainfall, and mist events have periodical variation, their main periods are 6 a, 7 a, 16 a, 12 a, and 12 a,respectively. (3) Urbanization has an effect on the warming records in Beijing. Extreme weather events may be influenced by certain weather systems, with less correlation with city development.