李雪松,罗亚丽,管兆勇. 2014. 2010年6月中国南方持续性强降水过程:天气系统演变和青藏高原热力作用的影响[J]. 气象学报, 72(3):428-446, doi:10.11676/qxxb2014.035
2010年6月中国南方持续性强降水过程:天气系统演变和青藏高原热力作用的影响
The persistent severe rainfall over southern China in June 2010:The evolution of synoptic systems and the Tibetan Plateau’s heating effect
投稿时间:2013-12-16  修订日期:2014-02-24
DOI:10.11676/qxxb2014.035
中文关键词:  南方持续性强降水  显式对流集合模拟  大气环流与天气系统  青藏高原热力作用
英文关键词:Persistent severe rainfall over southern China  Convection-permitting ensemble simulation  Circulation and weather systems  Tibetan Plateau's heating effect
基金项目:国家重点科学研究发展计划973项目(2012CB417202)、国家自然科学基金项目(41175049、41221064)、国家科技支撑计划项目(2012BAC22B03)。
作者单位E-mail
李雪松 南京信息工程大学气象灾害省部共建教育部重点实验室, 大气科学学院, 南京, 210044
中国气象科学研究院灾害天气国家重点实验室, 北京, 100081 
 
罗亚丽 中国气象科学研究院灾害天气国家重点实验室, 北京, 100081 yali@cams.cma.gov.cn 
管兆勇 南京信息工程大学气象灾害省部共建教育部重点实验室, 大气科学学院, 南京, 210044  
摘要点击次数: 3157
全文下载次数: 6177
中文摘要:
      2010年6月中国南方发生持续性强降水,其强度与2008年6月相当,超过近年来其他年份。但是,与2008年6月相比,2010年6月对流层中低层低值系统活动在青藏高原至长江中下游地区异常频繁,副热带高压(副高)位置异常偏西、强度偏强,导致低层异常风场辐合区及强降水区域相对偏北。分析2010年6月14—24日中国南方连续出现的4次持续性强降水过程,发现南亚高压、对流层中层的中纬度槽脊和西太平洋副高以及低层切变线和东移低涡是造成持续性强降水的主要天气系统。利用WRF模式对2010年6月强降水过程实施显式对流集合模拟试验,在控制试验重现观测到的地面降水和天气系统特征的基础上,在敏感性试验中将青藏高原的地表短波反照率修改为1.0,对比两组模拟试验的结果表明:控制试验中青藏高原的地表感热加热作用使得高原及其周边地区的大气温度发生变化,相应的热成风平衡调整使得对流层低层至高层大气环流和天气系统特征发生显著变化,增强了中国南方的持续性降水。200 hPa青藏高原西部形成反气旋性环流异常,东部形成气旋性环流异常,青藏高原东部南下的冷空气加强,中国南方辐散增强;500 hPa青藏高原北部的脊加强,中国东部的槽加深,副高西北侧的西南风明显增强,从青藏高原向下游传播的正涡度也显著加强;850 hPa的低涡强烈发展并逐步东移,华南沿海的西南低空急流更为强盛,导致降水区的水汽辐合、上升运动及降水强度都增强。
英文摘要:
      Persistent severe rainfall occurs over southern China during June 2010, with a magnitude being comparable to June 2008 and exceeding the other recent years. The June of 2010 is characterized by frequent occurrences of low-value systems in the middle-and low-troposphere from the Qinghai-Tibet Plateau to the lower reaches of the Yangtze River, and the significantly intensified West Pacific subtropical high (WPSH), leading to more northward located low-level anomalous wind convergence and rain bands compared to June of 2008. Analyzing the four successive persistent severe rainfall events over southern China during 14-24 June 2010, it is found that the South Asian high, the middle-latitude trough and ridge and the WPSH in the middle troposphere, as well as the shear lines and eastward-moving vortices in the lower troposphere are the main synoptic systems inducing the persistent severe rainfall. Moreover, an ensemble of convection-permitting simulations (CTL) is carried out using the WRF model for these rainfall events in June 2010. The ensemble mean successfully reproduces the observed evolutions of precipitation and weather systems. Another ensemble of simulations (SEN) with the surface albedo over the Tibetan Plateau and its southern slope being changed artificially to one, otherwise it is identical to CTL, is carried out. Comparison between CTL and SEN suggests that the surface sensible heating of the Tibetan Plateau in CTL significantly effects the temperature distributions over the plateau and its surroundings and the thermal wind adjustment consequently changes atmospheric circulations and properties of synoptic systems from the lower to upper troposphere, which significantly intensifies the persistent severe precipitation over southern China. Specifically, at 200 hPa, anticyclonic and cyclonic anomalies are formed over the western and eastern plateau, respectively, which enhances the southward cold air intrusion along the eastern plateau and intensifies the divergence over southern China; at 500 hPa, the ridge over the northern plateau and the trough over eastern China are strengthened, the southwesterly flows along the northwestern side of the subtropical high are intensified, and the positive vorticity propagation from the plateau to the downstream is also enhanced significantly; and at 850 hPa, the low-pressure vortices strongly develop and move eastward while the southwesterly low-level jet over the South China coasts is intensified as shown in CTL, leading to stronger water vapor convergence and upward motion over the precipitation region.
HTML   查看全文   查看/发表评论  下载PDF阅读器
分享按钮