The persistent heavy rainfall over southern China in June 2010: Evolution of synoptic systems and the effects of the Tibetan Plateau heating
The persistent heavy rainfall over southern China in June 2010: Evolution of synoptic systems and the effects of the Tibetan Plateau heating
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DOI：
10.1007/s13351-014-3284-3
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发表时间：
2014-10
影响因子：
3.2
通讯作者：
Xuesong Li;Yali Luo;Z. Guan
中科院分区：
文献类型：
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作者：
Xuesong Li;Yali Luo;Z. Guan
以2010年6月14-24日发生的4次持续性强降水过程为研究对象，分析了青藏高原地面加热对2010年6月中国南方暴雨的影响。主要天气系统包括对流层中层的南亚高压、中纬度槽脊、西太平洋副热带高压以及对流层低层的切变线和东移低涡。对流允许模拟（CTL）的合奏进行与WRF模式，这些降雨事件，成功地再现了观测到的降水和天气系统的演变。另一个模拟集合（SEN）与TP及其南坡上的表面重叠人为地改变为一个，即，该表面不吸收任何太阳能加热，否则它是相同的CTL，也执行。对比分析结果表明，青藏高原上的地面感热加热对高原及其周边地区的温度分布有显著影响，热成风的调节作用改变了大气环流和天气系统的性质，导致了华南地区降水的增强。200 hPa，高原西部和东部分别形成反气旋和气旋性异常，增强了冷空气沿着青藏高原东部南下入侵和华南地区的辐散;在500 hPa，北方高原高压脊和我国东部低压槽加强，副高西北侧沿着的西南气流增强，高原向下游的正涡度传播也明显增强，在850 hPa，低压涡强烈发展并东移，华南地区的西南低空急流加强，导致降水区水汽辐合和上升运动增强。
This study investigates influencing weather systems for and the effect of Tibetan Plateau (TP)’s surface heating on the heavy rainfall over southern China in June 2010, focusing on the four persistent heavy rainfall events during 14–24 June 2010. The major weather systems include the South Asian high, midlatitude trough and ridge, western Pacific subtropical high in the middle troposphere, and shear lines and eastward-moving vortices in the lower troposphere. An ensemble of convection-permitting simulations (CTL) is carried out with the WRF model for these rainfall events, which successfully reproduce the observed evolution of precipitation and weather systems. Another ensemble of simulations (SEN) with the surface albedo over the TP and its southern slope changed artificially to one, i.e., the surface does not absorb any solar heating, otherwise it is identical to CTL, is also performed. Comparison between CTL and SEN suggests that the surface sensible heating of TP in CTL significantly affects the temperature distributions over the plateau and its surroundings, and the thermal wind adjustment consequently changes atmospheric circulations and properties of the synoptic systems, leading to intensified precipitation over southern China. Specifically, at 200 hPa, anticyclonic and cyclonic anomalies form over the western and eastern plateau, respectively, which enhances the southward cold air intrusion along the eastern TP and 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 its downstream is also enhanced significantly; at 850 hPa, the low-pressure vortices strongly develop and move eastward while the southwesterly low-level jet over southern China strengthens in CTL, leading to increased water vapor convergence and upward motion over the precipitation region.