The 2019–2020 Black Summer wildfires wrought destruction across Australia and exposed millions of people to air pollution. Using a new school-based observational network alongside long-standing observations, we provide the first assessment of spatiotemporal variations in Black Summer's air pollution impacts across Sydney, including how meteorology modulated the severity and timing of these episodes. Throughout the summer, hourly fine particulate matter (PM_2.5) concentrations at schools often exceeded 25 μg m⁻³ (i.e. the national daily average standard for PM_2.5) for up to 8 h, with PM_2.5 spikes frequently reverberating across Sydney, creating city-wide impacts. However, timing and magnitude varied markedly with location, and a geographic sequence of impacts was evident, reflecting smoke transport by the passage of synoptic features, especially pre-frontal troughs. Temperature, dew point temperature, and air pressure had significant, mainly positive non-linear associations with PM_2.5, whereas negative relative humidity‒PM_2.5 associations increased in strength at ~70% humidity, and negative wind speed‒PM_2.5 associations reversed at higher speeds reflecting increased synoptic-scale advection of PM_2.5. This study provides insights into the complex spatiotemporal variations in air pollution during wildfires and the corresponding influential meteorological factors. Together, these insights can inform improvements in air quality forecasting and support planning to reduce exposure to smoke emissions, thus increasing the preparedness requirements of society to mitigate the impacts of severe wildfires.

2019-2020 年的黑色夏季野火在澳大利亚造成了破坏，并使数百万人暴露在空气污染中。使用新的基于学校的观测网络以及长期观测，我们首次评估了“黑色夏季”对悉尼空气污染影响的时空变化，包括气象学如何调节这些事件的严重程度和时间。整个夏季，学校每小时的细颗粒物 (PM _2.5 ) 浓度往往超过 25 μg m ⁻ ³（即 PM _2.5的国家日平均标准）长达 8 小时，其中 PM _2.5高峰经常在悉尼回荡，造成全市范围的影响。然而，时间和强度随位置而显着变化，并且影响的地理序列是明显的，反映了通过天气特征特别是前额叶低谷的通过的烟雾传输。温度、露点温度和气压与 PM _2.5呈显着的主要正非线性关联，而负相对湿度 - PM _2.5关联在约 70% 的湿度下强度增加，负风速 - PM _2.5关联在较高湿度下逆转反映 PM _2.5天气尺度平流增加的速度. 这项研究为野火期间空气污染的复杂时空变化以及相应的影响气象因素提供了见解。总之，这些见解可以为空气质量预测的改进提供信息，并支持减少烟雾排放的规划，从而提高社会的准备要求，以减轻严重野火的影响。