In order to study the impact of cross-border transportation of biomass burning from peripheral areas on the air quality in Yunnan Province, a southwestern border province in China, during spring, specifically in response to the large-scale pollution process in Yunnan from April 1 to 18, 2024, three border cities in Yunnan Province, namely Mengzi City, Mangshi City, and Mengla County, were selected as examples. Ground-based particle laser radar network observations, combined with ground air quality data, meteorological data, and MODIS satellite remote sensing data, were used, along with the HYSPLIT backward trajectory model, potential source concentration weight trajectory analysis method, and other technical means, to analyze the spatiotemporal distribution characteristics and motion trajectories of pollutants and to evaluate their impact on the air quality in Yunnan province. The results show that in April 2024, there were numerous fire points in the peripheral areas of Yunnan province. Under the dominance of the southwest monsoon, the three border cities were prone to the cross-border transport of biomass burning from Myanmar, Thailand, Laos, and Vietnam during the period from night to morning, with a lag time of 1.5 to 72 hours and a coverage range of up to 2300 kilometers. During the pollution growth process, the air quality in Mengzi City was mainly affected by mixed-layer transport from Myanmar, Laos, and Vietnam. The transport from eastern Myanmar and passing areas led to an increase of about 30 μg/m³ in the ground PM_2.5 concentration in Mengzi City on the afternoon of April 6th. Mangshi City was mainly affected by surface-level transport and low-altitude subsidence from Myanmar and Bangladesh, while Mengla County was mainly affected by surface-level transport and low-altitude subsidence from Laos, Myanmar and Thailand. Overall, Myanmar has the greatest impact on the air quality of border cities in Yunnan Province. 

为研究中国西南边境省份云南省空气质量在春季受外围地区生物质燃烧跨境传输的影响, 针对2024年4月1—18日云南省大范围污染增长过程, 以蒙自市、芒市和勐腊县3个云南省边境城市为例, 利用地基颗粒物激光雷达组网观测, 结合地面空气质量数据、气象数据和MODIS卫星遥感数据, 利用HYSPLIT后向轨迹模式和潜在源浓度权重轨迹分析法等多种手段, 分析污染物的时空分布特征和运动轨迹, 评估其对云南省空气质量的影响。结果表明, 2024年4月云南省外围地区火点数量较多, 在西南季风主导下, 夜间至上午时段, 蒙自市、芒市和勐腊县易受缅甸、泰国、老挝和越南等地生物质燃烧跨境传输的影响, 滞后时间为1.5~72 h, 覆盖范围可达2300 km。在污染增长过程期间, 蒙自市空气质量主要受缅甸、老挝和越南等地污染混合层内输送影响, 缅甸东部以及途经地区的污染输送导致4月6日下午蒙自市地面PM_2.5浓度升高约30 μg/m³。芒市主要受缅甸和孟加拉国等地污染贴地输送以及低空沉降影响, 勐腊县主要受老挝、缅甸和泰国等地污染贴地输送以及低空沉降影响。总体来看, 缅甸对云南省边境城市空气质量的影响最大。