Brown haze, observed over some cities during the winter months, has been found to be associated with poor surface air quality and negative health outcomes. While the link between the atmospheric boundary layer (ABL) structure and surface air quality is well-established, the degree to which boundary layer structure influences local brown haze formation is unknown. Using continuous ceilometer data from seven winters, we investigate the influence of the ABL structure in relation to surface air pollution and brown haze formation over an urban area of complex coastal terrain in the Southern Hemisphere city of Auckland, New Zealand. When days with severe brown haze are compared with those when brown haze is expected but not observed (based on favorable meteorology and high surface air pollution levels), the presence of severe brown haze is found to coincide with a significantly shallower boundary layer during both the daytime convective phase (∼48% lower) and the early-morning nocturnal phase (∼28% lower). Severe brown haze is also found to be associated with significantly reduced morning transition growth rates (70 m h⁻¹) compared to days on which brown haze is expected but not observed (170 m h⁻¹). Our results also suggest the entrainment of pollutants stored in the residual layer may contribute to the severity of the haze. This study illustrates the complex interactions between the ABL structure, air pollution, and the presence of brown haze, and demonstrates the utility of a ceilometer instrument in understanding and predicting the occurrence of brown haze events.

在冬季的一些城市中观察到的褐色雾霾，与地面空气质量差和对健康的负面影响有关。虽然大气边界层（ABL）结构与地面空气质量之间的联系已得到充分确立，但边界层结构影响局部褐色雾霾形成的程度尚不清楚。利用来自七个冬季的连续云高仪数据，我们研究了南半球新西兰奥克兰市复杂沿海地形市区上的ABL结构与地面空气污染和褐雾形成的关系。当将有严重褐色雾霾的日子与预期但没有观察到褐色雾霾的日子进行比较时（基于有利的气象学和较高的地面空气污染水平），在白天对流阶段（约低48％）和夜间夜间阶段（约低28％）期间，发现严重的褐色混浊与边界层明显较浅相吻合。还发现严重的褐色混浊与早晨过渡生长速率（70 m h^-1）与预计出现但没有观察到雾霾的日子相比（170 m h ^-1）。我们的结果还表明，残留在残留层中的污染物的夹带可能会导致雾霾的严重性。这项研究说明了ABL结构，空气污染和褐色雾霾之间的复杂相互作用，并证明了云高仪仪器在理解和预测褐色雾霾事件发生中的作用。