北京地区长期增暖中的一个减缓期

A Slowing-down Period During the Long-Term Warming in the Beijing Region

采用北京地区13站1960—2008年和20站1978—2008年的气温观测资料,分析其变化的时空特征。1960—2008年北京地区平均气温呈上升趋势。1960—1969年、1969—1983年和1985—1998年北京地区平均气温变化趋势分别为-1.27℃/10a、0.79℃/10a和1.17℃/10a,即经历了快速下降、上升和快速上升3个时段。而1998—2008年出现了长期增暖中的一个减缓期,13站和20站资料揭示的平均气温变化趋势分别为0.02℃/10a和-0.05℃/10a。1998—2008年,城区总体仍然呈增暖趋势,北城的增暖速率是南城的两倍。远郊山区或靠近水体和公园的城镇站呈降温趋势。

The spatial-temporal variations of observed temperature based on the 13 stations for 1960-2008 and the 20 stations for 1978-2008 in the Beijing region were analyzed.A rapid decreasing rate of-1.27 ℃/10a during 1960-1969,an increasing rate of 0.79 ℃/10a during 1969-1983,and a rapid increasing rate of 1.17 ℃/10a during 1985-1998 are observed by the 13-station temperatures.A slowing-down period from 1998 to 2008 with trends of 0.02 ℃/10a and-0.05 ℃/10a are revealed by the 13-station and 20-station observations,respectively.During 19982008,warming trend still exists in the urban region.The warming rate in the northern urban region is double of that in the southern part.In the rural area or the stations near a water body or park,decreasing trends are observed during 1998-2008.