地理学报 ›› 1999, Vol. 66 ›› Issue (2): 125-133.doi: 10.11821/xb199902004

• 论文 • 上一篇    下一篇

西伯利亚高压的长期变化及全球变暖可能影响的研究

龚道溢, 王绍武   

  1. 北京大学地球物理系,北京100871
  • 收稿日期:1998-06-24 修回日期:1998-10-14 出版日期:1999-03-15 发布日期:1999-03-15
  • 基金资助:
    国家自然科学基金

LONG TERM VARIABILITY OF THE SIBERIAN HIGH AND THE POSSIBLE CONNECTION TO GLOBAL WARMING

Gong Daoyi, Wang Shaowu   

  1. Department of Geophysics, Peking University, Beijing 100871
  • Received:1998-06-24 Revised:1998-10-14 Online:1999-03-15 Published:1999-03-15
  • Supported by:
    Supported by National Natural Science Foundation of China,No.49635190

摘要: 本文利用历史海平面气压资料建立了近百年来的西伯利亚高压强度指数。1960年代是近百年来西伯利亚高压强度最强的一段时期,1980年代后期到1990年代则是近百年来最弱的一段时期。40年左右的年代际变化比较明显。用西伯利亚高压强度能较好地解释近几十年来我国冬季气温变化的特征。近百年来西伯利亚高压的变化可能仍然以自然变率为主,全球变暖的影响还较弱。但是,在全球持续变暖的情景下,西伯利亚高压的强度将会显着减弱,5年~6年左右年际尺度的变率将会加强。

关键词: 西伯利亚高压, 气候变率, 全球变暖

Abstract: The Siberian High is one of the most important circulation systems influencing the climate of eastern Asia in winter. In this study, the intensity index of the Siberian High is defined as I=? 苮72n=1Pnδncosφn? 苮72n=1δn cosφn where Pn is the sea level pressure at grid n , φn is latitude, δn =1 when Pn ≥1 028 hPa, and δn =0 when Pn <1 028 hPa. This index indicates the level of anomaly from the average atmospheric conditions in the core region of the Siberian High. A long time series of the intensity index for the last hundred years was established on the basis of monthly mean sea level pressure data for the northern hemisphere obtained from CRU/UEA. Power spectrum analysis reveals that, for about four decades, the index showed decadal variability. In the 1960s, the Siberian High’s intensity was the highest. During the late 1980s and the early 1990s, the intensity was the lowest. The intensity was strongly correlated with the winter temperature of East Asia. A great deal of the temperature variance in the region 110°E~140°E and north of Bangladesh can be explained by the intensity index. Our calculation of the temperature data for 65 winters shows that 43 6 percent of the variance of North China’s winter mean temperature can be accounted for by the intensity of the Siberian High. The possible impact of global warming on the variability of the High was also investigated using the atmosphere ocean coupled general circulation model (HADCM2). The result of CO2 increase at the rate of 1% per year on global warming was compared with the result of control integration. It was found that in the last hundred years the impact of global warming on the Siberian High was not evident and that the High’s own natural variability played a more important role. Continuous warming in the future will significantly reduce the intensity of the system. However, the change will not be linear. With increasing Co2, variability at 5~6 year inter annual scale can be expected to become more prevalent.

Key words: Siberian High, climate variability, global warming

中图分类号: 

  • P467