关键词: 积温, 持续期, 初日, 终日, 滑动平均

Abstract: In this paper, the accumulated temperatures higher than 0℃ (T≥0℃) and 10℃(T≥10℃) in North China and Northeast China during the period of 1956~1995 are calculated, and their change tendency are analyzed. The results indicate that the accumulated temperature in North China and Northeast China has an obvious changing tendency, and in 80~90’s the accumulated temperature raised gradually as a wave. The accumulated temperature is closely related to the duration of T≥0℃ (or T≥10℃) period and their changing tendency are similar. The results of the regression analysis between the accumulated temperature and the duration of T≥0℃ period and mean annual temperature show that if the mean annual temperature raise 1℃ the accumulated temperature of T≥0℃ will increase about 117～252℃·d and the duration of T≥0℃ period will extend about 5～13.5days.

Key words: The accumulated temperature, The accumulated temperature, The duration of T≥0℃ (or T≥10℃) period, The first day, The last day, Moving average