摘要
2002年9月27日、2003年6月28日和2004年6月24日山东部分地区遭受了不同程度的灾害性天气,雷达观测分析表明是3次超级单体风暴所致,0927风暴尺度和天气现象次于0628和0624风暴。利用济南多普勒雷达探测资料,结合天气形势,对这3次典型超级单体强度结构、流场结构及其演变过程进行了仔细的分析,结果表明:地面中尺度辐合触发了不稳定能量的释放,引发了强对流天气发生;风暴形成阶段表现为不同的演变特征,0927风暴表现为多单体传播型,0628风暴表现为单体自身发展型,0624风暴表现为群发单体合并型;移动路径相似,都属于右移风暴,偏离风暴承载层平均风右侧30°—70°,移动速度约为风暴承载层平均风速的45%—70%;发展成熟阶段最大强中心高度表现不同,0927风暴位于单体底部, 0628风暴位于单体中下层,0624风暴位于单体中层以上,最大反射率因子和垂直积分液态含水量(VIL)表现也有差别,0624风暴最强,0628风暴次之,0927风暴相对较弱。风暴旺盛成熟阶段表现为典型的超级单体特征,有界弱回波区(BWER)和中气旋;风暴旺盛成熟阶段风暴垂直流场结构有相似性,低层气旋性辐合,中层近似于气旋性旋转上升,高层气流辐散;中层水平流场结构存在较大差异,0927和0624风暴为双涡管式旋转结构,0628风暴为单涡式的气旋旋转结构。
Three supercell storms on 24 June 2004（0624）, 28 June 2003（0628）, 27 September 2002（0927） produced different damages in Shandong province respectively, the scale and weather phenomena of storm 0927 were inferior to storms 0628 and 0624. The inner structure and evolvement of the three storms were analyzed in details based on the CINRAD/SA radar data in the combination with weather charts. The results show that surface meso-scale convergence triggered release of unstable energy, which brought about severe convection. There were different evolvement characteristics on storm development stages, storms 0927, 0628 and 0624 displayed multi-cell propagation, single-cell evolution, and multi-cells mergence, respectively. The storm tracks were similar each other, they were right moving supercell storms, i.e. moved at an angle of 30° - 70° to the right of the mean wind, at a speed of about 45 % 70 % of the mean wind speed. In the mature stage, the maximum reflectivity height was at low level in storm 0927, middle level in storm 0628, and middle-upper level in storm 0624, respectively. Three storms possessed almost all typical features of supercell storms： WER, BWER, and mesocyclone. An organized mesocyclone began at the middle height of an updraft, it deepened gradually downwards and upwards, and became a typical mid-level mesocyclone with strong updrafts. The signatures of the vertical structure of airflows in three storms were similar, i.e. significant convergence at low-level, nearly pure rotation at mid-level, and divergent rotation at upper-level. However, signatures of mid-level horizontal airflows in three storms were different： at mid-level there was a single vortex in storm 0628, and a double-vortex flow pattern in storms 0927 and 0624. The horizontal structure of double-vortex flow pattern is hard to be blown away by environmental airflow, thus the storm could resist for a longer time-period relative to single vortex storm.
出处
《气象学报》
CAS
CSCD
北大核心
2009年第1期133-146,共14页
Acta Meteorologica Sinica
基金
国家自然科学基金项目(40575012)
山东省科学技术厅攻关项目(2007GG20008001)。
关键词
超级单体
中气旋
双涡管式
旋转结构
Supercell storm, Mesocyclone, Inner structure, Double-vortex flow pattern
