Anticyclone Driven Heat Waves Intensify Beijing's Urban Boundary‐Layer Turbulence

作者：Na Tang, Jianping Guo, Juan Chen, Zhibo Li, Xiaoran Guo, Yuping Sun, Hui Xu, Zhen Zhang, Ning Li, Liping Zeng, Miao Yu, Tianmeng Chen · 发表于：Geophysical Research Letters · 年份：2025 · DOI：10.1029/2025gl115800 · 被引用次数：3 · 研究领域：Meteorological Phenomena and Simulations、Climate variability and models、Wind and Air Flow Studies

Abstract Heat waves (HWs), intensifying under climate change, critically modulate planetary boundary‐layer (PBL) turbulence through poorly constrained mechanisms. Leveraging unique radar wind profiler network measurements across three Beijing during the record‐breaking 2023 summer (16 HW days), we quantify the turbulence dissipation rate (ε) variations under anticyclone driven HWs (hereafter called Type AC, 40% dominance). The mean ε in the PBL during HWs is elevated by ∼55%, demonstrating heat‐amplified turbulence. Divergent forcing regimes emerges–surface‐air temperature difference (T s −T a ) governs PBL turbulence generation while vertical wind shear (VWS) dominates mechanical mixing aloft. Intriguingly, clouds play a dual role: they enhance VWS‐induced turbulence under normal conditions but reduce heat driven turbulence. These findings establish the first observational evidence of synoptic‐scale thermal‐dynamic decoupling in urban PBLs during extreme heat, providing mechanistic insights for improving megacity air quality forecasting and heat‐stress resilience strategies.