Urban morphology modulates thunderstorm process and associatied cloud-to-ground lightning activity over Beijing metropolitan region

• DOI: 10.5194/acp-2024-3
• Publication Date: 2024-04-16T04:45:59Z
• Authors: Tao Shi; Yuanjian Yang; Gaopeng Lu; Zuofang Zheng; Yucheng Zi; Ye Tian; Lei Liu; Simone Lolli
• Keywords: Lightning; Urban Morphology; Urban Heat Island; Sea breeze

Abstract. The effect of urban barriers may have a significant impact on the patterns thunderstorm processes and lightning activity, but there is still lack comprehensive mechanical explanations. observational analysis carried out in this study found that cloud-to-ground (CG) lighting activity tends to cluster around outer boundaries mega cities, while, opposite, CG gathers within small-sized city. When squall line originating from type mesoscale convective system (MCS) known as '0713' passed through built-up area, barrier rough underlying surface contributed separation cold pool. This led weakening vertical airflow breaking convergence line, ultimately triggering bifurcation thunderstorm. Simulation results complement these observations. buildings outside 5 Ring Road (RR) are replaced with bare soil, pool minimized. Furthermore, density also influenced strength effect. Therefore, specific morphologies were identified critical factor modulating organization process thunderstorms. offers fundamental foundation technical support for predicting assessing risks. It holds implications understanding excess warming, its prediction assessment, resulting thermal risk, by factors such ventilation, sea breezes, geophysical environment coastal cities.