J4 ›› 2003, Vol. 21 ›› Issue (3): 8-13.

• 论文 • 上一篇    下一篇

秦岭邻近地区旬降水气候学及其大气环流特征

刘晓东1方建刚2杨续超1李新周1   

  1. 1.中国科学院地球环境研究所,陕西西安710075 ;2陕西省气象局,陕西西安710015
  • 收稿日期:2003-06-03 修回日期:2003-09-02 出版日期:2003-09-30 发布日期:2003-09-30
  • 作者简介:刘晓东(1963一),男,研究员,博士生导师,主要从事气候学研究.E一mail: liuxd @loess.llqg.ac.cn
  • 基金资助:

    国家自然基金项目((40121303) ,国家科技部项目((2001CCBOOl00,G1999043401)及中科院院长基金资助

Clinratology of dekadly precipitation around the Qinling mountains and characteristics of its atmospheric circulation

 LIU Xiao-Dong1, FANG Jian-Gang2, YANG Xu-Chao1, LI Xin-Zhou1   

  1. 1 .Institute of Earth Environment ,Chinese Academy of Sciences ,man ,710075 ,China;
            2. Meteorological Bureau of Shanxi Province ,man  710015 ,China
  • Received:2003-06-03 Revised:2003-09-02 Online:2003-09-30 Published:2003-09-30

摘要:

利用秦岭及其邻近地区76个气象台1961~2000年的旬降水量和NCEP/ NCAR 850hPa格点风场资料,分析了该地区的降水气候时空特征及其与大气环流变化的联系。结果表明‘秦岭地区多年平均汛期出现在6月下旬至10月上旬,其间7月上旬和9月上旬先后出现两次降水峰值。该地区平均汛期降水量为403mm.占年总降水量的60 % .秦岭南侧气候平均汛期降水量明显高于秦岭北侧.但秦岭南、北汛期降水年际变化基本一致。从流场分析看,秦岭及其邻近地区的汛期降水既受西南季风,又受到东南季风系统的影响。合成分析表明,汛期降水量偏多(少)的年份通常对应于同期对流层低层研究区南侧偏南气流的增强(减弱)。回归分析发现.汛期中旬雨量增加与超前2旬索马里急流和热带印度洋西南气流增强以及超前1旬及同期台湾附近距平反气旋的发展密切相关。

关键词: 秦岭, 旬降水, 大气环流

Abstract:

Using 1961一2000 dekadly precipitation from 76 weather stations in the Qinling mountains and the surroundings and largescale grid winds at 850 hPa from NCAR/ NCEP ,the climatology spatial一temporal characteristics of the precipitation and their as sociations with the atmospheric circulation have been analyzed in this paper. The results show that the flood season for the 40一year average occurs in the period from the third dekad of June to the first dekad of October ,during which there are two peaks of precipitation ahe first dekad of July and the first dekad of September. The rainfall in the south side of the Qinling mountains is obviously higher than that in the north side ,although the interannual variations of both are basically consistent. The Qinling mountains and the surroundings are mainly controlled by the southwesterly monsson in the flood season ,e}ecially in the midsummer ,but are mainly impacted by the southeasterly monsoon in the early autumn. The composite analyses show that when theprecipitation is more(less)than normal ,the southerly wind at the south boundary of the study area is often stronger(weaker) than normal in the flood season. By the regression analyses ,it is found that the increased rainfall in a dekad in the flood season generally corresponds to the strengthened Somali
Jet and southwesterly monsoon in the dekad with a two一dekad lead ,and an anomaly anticyclone near Taiwan in the one一dekadlead
dekad and the same dekad.

Key words: Qinling mountains, dekadly precipitation, atmospheric circulation

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