Statistical Analysis of Quasi-Linear Convective Systems Over the Beijing-Tianjin-Hebei Region During the Warm Season

• DOI: 10.2139/ssrn.4306160
• Publication Date: 2022-12-18T03:08:39Z
• Authors: Xinyan Cui; Mingxuan Chen; Linye Song; Chun Li; Lei Han
• Keywords: Statistical Analysis; Mesoscale convective system

The quasi-linear convective systems (QLCSs) in the warm season (May-September) during 10-year period 2011-2020 over Beijing-Tianjin-Hebei region are investigated. synoptic patterns divided into four types according to potential height field at 500 hPa. environment is unstable near locations of convection initiations (CIs) QLCSs, where temperature and humidity high there weak updraft low-level vertical wind shear. These features beneficial for formation rapid development strong convection. Furthermore, spatio-temporal distribution characteristics morphology, evolution, propagation QLCSs quantified using a skeleton-based automatic identification technology (SBAIT). CIs appear both mountains plains, with highest frequency foothills approximately 200 m, because topographic forcing that causes southerly moist flow rise foothills. There more plains daytime than night, owing peak solar heating day. Further, generally characterized as shear compared those mountains. Most 600-km long 4 km less 60 wide. they have an aspect ratio 45 area 20,000 km2. terrain CI time strongly influence morphology intensity QLCSs. Following initiation, most dissipate within 300 away from locations. Those initiate mostly early evening, whereas night morning. propagate southeast day, while northeast least number northwest. Slow-moving lives exhibit slightly reduced area, fast-moving ones shows slight increase. westsouthwest-eastnortheast (WSW-ENE), southwest-northeast (SW-NE), west-east (W-E) directions, few them westnorthwest-eastsoutheast (WNW-ESE) direction well. downslope whose directions nearly their directions. If continue develop then become long-duration systems. However, slow-moving may train effect, i.e., transmission cells constant respect system, which remarkably enhances sustainability. Moreover, exude certain impact on diurnal variations distinct different patterns.