The study utilizes SA Doppler weather radar data from Dalian and Dandong,combined with surface ob-servations and ERA5 reanalysis data,to conduct a comparative analysis of the synoptic background and mecha-nisms of two mild-wet downburst events over the Liaodong Peninsula:the first on September 11,2020(Event Ⅰ),and the second on September 10,2021(Event Ⅱ).Results indicate that both events occur under the influence of a Northeast Cold Vortex.Event I is associated with a cold vertex transformed from a northward typhoon,while Event Ⅱ involves a cut-off low.Both events are characterized by unstable atmospheric stratifications of"upper-wet and lower-dry",with skew-T diagrams showing an upward-opening"bell-shaped"structure.Near-surface temperature lapse rates are nearly dry-adiabatic.The precipitable water content exceeds 30 mm.The lifting condensation level is low,with CAPE and DCAPE values being relatively small.The 0-6 km wind shear intensity is significantly stron-ger in Event Ⅱ than in Event Ⅰ.The thunderstorm gale events in both cases are induced by wet microbursts,with E-vent I involving an isolated storm and Event Ⅱ embedded within a squall line system.In both cases,the Doppler ra-dar reflectivity notches exceeding 45 dBz appear earlier at higher elevation angles than at lower elevation angles prior to the wet microbursts.
Northeast Cold Vortex(NCV)Cut-off lowThunderstorm gale
国家科技期刊平台
NSTL
万方数据
