摘要
利用常规气象观测资料、NCEP/NCAR 1°×1°6 h分析资料和2.5°×2.5°日平均再分析资料、自动雨量站资料,采用统计对比分析、诊断分析等方法,对三门峡市2014年9月7-18日连阴雨过程的环流形势、物理量场进行分析,找出此次连阴雨天气的主要成因,结果表明:1)南亚高压的异常偏北偏强为连阴雨天气提供了有利的大尺度环流背景。2)副热带高压的长时间稳定维持,对减缓低槽和切变线移速、促使暖湿气流向北输送十分有利。3)乌拉尔山高压脊较常年同期偏弱,与常见连阴雨天气乌拉尔山高压脊异常偏强的形势有所不同。4)稳定的副热带高空西风急流与副高外围的西南低空急流耦合,为连阴雨提供了持续的上升运动和水汽辐合。5)强降水的产生只有充足的水汽供给是不够的,还必须在水汽的输送区有明显的水汽辐合。6)低层强烈的垂直上升运动为此次连阴雨期间暴雨的形成提供了有利的动力条件。
In this paper, the analysis was carried out for the circulation situation, physical quantity field to find out the main cause of the continuous rain weather during September 7--18, 2014 by the method of statistic contrastive analysis and diagnostic analysis etc. The data of NCEP/NCAR 1°× 1 ° 6 h, NCEP/NCAR 2.5°× 2.5° daily average reanalysis data, automatic station rainfall data was used. The result showed as follows. 1 ） Going northwards and much stronger anomalously of South Asia high provided the favorable large-scale circulation conditions for this continuous rain process. 2）The long-term stable maintenance of subtropical high was advantageous to reduce moving speed of low trough and shear line, and force the northwards transportation of warm-wet air flow. 3 ） Urals high-pressure ridge was weaker than that in normal years, and was quite different with its abnormal stronger situations in common contin- uous rain weather. 4）The coupling between stable subtropical upper-level jet stream and southwest low- level jet stream outside subtropical high provided continuous ascending motion and moisture convergence for continuous rain. 5）It was not enough to generate sufficient water vapor for heavy rainfall, and there must also had obvious water vapor convergence in the transition zone of water vapor. 6） The low-level strong vertical ascending motion effectively drived the development of storm rainfall during this continuous rain.
出处
《气象与环境科学》
2017年第2期115-119,共5页
Meteorological and Environmental Sciences
基金
三门峡市科技计划项目(2013020318)
三门峡市气象局科研项目(SQ201304)资助
关键词
连阴雨
高空急流
低空急流
南亚高压
continuous rain
upper level jet
low level jet
the South Asian high
