Variation characteristics of temperature in northeastern border region of Qinghai-Xizang Plateau

Based on the monthly temperature data of 12 stations in the northeast border region of Qinghai-Xizang plateau,the variation characteristics of temperature in recent 40 years were analyzed.The results showed that the warm abrupt change of yearly mean temperature occurred in 1987,the minimum temperature increased from early of 1980s' in this region,in the 1990s' the minimum temperature still increased while the maximum temperature became increasing.The mean temperatures of summer,autumn and winter all apparently increased.The increasing speed of winter was obviously faster than other seasons,and the warm abrupt change of winter mean temperature occurred in 1978 earlier than in other years.The increasing trend of spring mean temperature was not apparently.The change of daily maximum temperature,daily minimum temperature and daily temperature was obviously different in different seasons.