Spatial-temporal characteristics of record-breaking temperature events over China in recent 46 years

Based on the theory of probability distribution of record-breaking events and daily high/low observational temperature data in China form 1960 to 2005, the spatial-temporal characteristics of record-breaking temperature are investigated. We found that the annual mean frequency of record-breaking high temperature is about 2.5 times greater than normal in 1976-2005, while for record-breaking low temperature is 4.5 times less. Record-breaking high temperature is obviously more than normal in Northwest, North China, Northeast and Tibet, while the record-breaking low temperature is obviously less than normal there. As to the relative trend of record-breaking temperature events, the record-breaking high temperature somewhat increases in most parts of China, but the record-breaking low temperature become less and less all over China. For the development trend of strength, the record-breaking high temperature events, have somet enhancement in high latitude areas of China, but the record-breaking low temperature events have no change or only eventually become weakening in this area and also in Xinhang and Tibet. It should to be payed attention that the strength of record-breaking low temperature events becomes obviously enhanced in south China. In studying the relationship of annual frequency of record-breaking high/low temperature events and pacific warm pool index, we found that there are significant correlations between them for most parts of China.