杨本湘, 陶祖钰. 2005: 青藏高原东南部MCC的地域特点分析. 气象学报, (2): 236-242. DOI: 10.11676/qxxb2005.023
引用本文: 杨本湘, 陶祖钰. 2005: 青藏高原东南部MCC的地域特点分析. 气象学报, (2): 236-242. DOI: 10.11676/qxxb2005.023
Yang Benxiang, Tao Zuyu. 2005: THE ANALYSIS OF LOCAL FEATURES OF MCC ON SOUTHEAST TIBETAN PLATEAU. Acta Meteorologica Sinica, (2): 236-242. DOI: 10.11676/qxxb2005.023
Citation: Yang Benxiang, Tao Zuyu. 2005: THE ANALYSIS OF LOCAL FEATURES OF MCC ON SOUTHEAST TIBETAN PLATEAU. Acta Meteorologica Sinica, (2): 236-242. DOI: 10.11676/qxxb2005.023

青藏高原东南部MCC的地域特点分析

THE ANALYSIS OF LOCAL FEATURES OF MCC ON SOUTHEAST TIBETAN PLATEAU

  • 摘要: 青藏高原东南部是一个对流天气频繁发生的地区。在该地区生成发展的MCC不仅给当地造成大范围的雷电和强降水天气,还对长江中下游地区的天气产生明显的影响。文中通 过对2001~2002年6~9月发生在该地区的16个MCC个例的分析,得出其具有明显的地域特点: (1) MCC最易发生在100°E附近的横断山脉地区和105°E附近的成都平原地区,且后者多于前者;(2) 它们都具有生命史短,水平尺度较小和生消变化快的特点,但东部型生消时间晚 ,降水量大;西部型生消时间早,降水量小;(3) 东部型和西部型MCC发生前的环流背景和 成熟阶段的垂直结构也有明显不同。东部型MCC在形成前中低层有明显的水汽输送,在成熟 阶段中低层有较强的正涡度环流,有较弱的垂直风切变,具有较为典型的MCC特征;而西部 型MCC在形成前中低层水汽输送不明显,成熟阶段的正涡度环流不强,处于较强高空急流的正下方,具有与强风暴相类似的一些特征。

     

    Abstract: The convective weather occurs on Southeast Tibetan plateau frequently. The MCCs create large scope of thunderstorm and severe rainfall on local regions. Furthermore, they influences the weather in the middle reaches even lower reaches of the Yangtze River evidently. The notable characteristics explored through 16 MCC cases were analyzed on which formed on Southeast Tibetan plateau from June to September in 2001 and 2002: Firstly, The regions on which MCC generate prone areas were the Hengduan Mountains′regions about 100°E (West Region)and the Sichuan basin nearly 105°E(East Region),and the number of MCC which formed on lat er was more than on former. Secondly, these two kinds of MCCs had common feature s such as shorter lifetimes, smaller scale and quicker change than MCCs formed o n other regions like America and the lower reaches of the Yangtze River, but the time when MCC generated and decayed on which ER was later on WR, and the precip itation of MCC on which ER was more than on WR. At last, the evident difference existed between MCC on which WR and on ER in the circulations before their formtion, and there were largely discrepancies in the vertical constructions at mature stage. Enormous vapor transportation appeared at low middle layer before MCC generated on ER and evident positive vorticity circulations dominated in their mature stage. Also, the vertical wind change was little. Obviously, the MCC on ER was typical MCC noted; Contrarily, there were no evident vapor transportation at lowmiddle level before MCC formed on WR, and in their mature, positive vor t icity circulations were not prominent which related to latent heat released by l ess rainfall, but there were strong upper jet stream up MCC on WR. It is natural ly that some characteristics of MCC on WR were similar to severe storm on extent . In conclusion, the differences in two kinds of MCCs formed on Southeast Tibeta n Plateau were connected with the altitude of the area on MCCs generated.

     

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