Impulse Weibull distribution for daily precipitation and climate change in China during 1961-2011

Based on a newly developed dataset containing daily precipitation in China at 0.5°intervals of longitude and latitude over the period 1961 to 2011, we find that statistical patterns of the daily surface precipitation data from the 3825 measurement sites can be described by a new Impulse Weibull (IWBL) probability distribution. By applying appropriate parameter identification techniques, we estimate all the parameters of the IWBL distribution for each site. We also examine the trends in annual and daily precipitation over the period 1961 to 2011. Results show that the probability of rainy days has decreased over time for over 90% the surface area of China, and that the extreme precipitation and annual precipitation have decreased for most of the area in China.