近40年北京地区强热岛事件初步分析

Primary Analyses on "Heat Island" Events in Beijing in Recent 40 Years

利用北京市1961-2004年间气象站及自动气象站逐日或逐时及每10min的日平均地面气温观测资料，给出了近44年北京市强热岛事件日的序列，划分了热岛日的大致标准，并分析了北京市强热岛事件日的时空分布特征。分析表明，在1961-2004年北京市出现了79例强热岛事件日，强热岛日主要出现在冬季，秋季次之，但夏季时有发生，热岛强度中心位于公主坟、天安门、大观园附近。观测发现，近44年间北京市强热岛日呈明显增多趋势，年际波动明显；强热岛日强度年际波动明显，但强度的年代际变化趋势并不明显。热岛强度一般在02～08时达到最强，在12～17时最弱，有时还出现负值，热岛消失。

Based on the daily, mean surface air standard stations and Automatic Weather Stations temperature data from 1961 to 2004 measured by the in Beijing, a series of the strong heat island（SHIE） events in Beijing over the past 44 years are given. Moreover, the analyses were also made on the temporal and spatial distribution characteristics of these events. The results indicated that 79 strong heat island events took place in Beijing during 1961-2004, mainly occurred in winter, secondly in autumn and occasionally in summer. The heat island centers were often located in the vicinity of Gongzhufen, Tiananmen Square or Daguanyuan in Beijing, which differed from the Haidian or Tongzhou centers as revealed in other research findings. Furthermore, it was found that during 44 years, there was an evident tendency that the number of SHIE increased with the time. Meanwhile, the SHIE intensity has an evident interannual fluctuation, but not interdecadal variation. In general, SHIE intensity reach the maximum value at 02：00～08：00, and it becomes gradually weakened or even falls into a negative value at 12：00～17：00.