阿克达拉站PM10和PM2.5质量浓度长期变化趋势及短期升高事件研究OA

Based on continuous observations of PM10 and PM2.5 at the Akedala regional atmospheric background station from 2011 to 2023,we employed statistical and meteorological correlation analyses,the HYSPLIT-4 mod-el,the potential source contribution function(PSCF),and the concentration-weighted trajectory(CWT)method to investigate the variation trends and source characteristics of PM10 and PM2.5 mass concentrations.The results showed that:(1)From 2011 to 2023,the annual average mass concentration of PM10 increased from 12.1 μg·m-3 to 23.2 μg·m-3,while PM2.5 increased from 7.3 μg·m-3to 10.8 μg·m-3,with annual growth rates of 0.81 μg·m-3·a-1 and 0.31 μg·m-3·a-1,respectively,indicating that PM10 increased faster than PM2.5.(2)PM10 and PM2.5 exhibited clear seasonal variations,with higher values in spring and winter and lower values in summer and autumn.The PM2.5/PM10 ratio displayed a bimodal distribution(0.4-0.5 and 0.8-0.9),where lower ratios indicated natural con-tributions and higher ratios reflected anthropogenic sources.(3)Air mass trajectory analysis suggested that PM10 primarily originated from eastern arid regions of Kazakhstan(PSCF values 0.4-0.7),whereas PM2.5 mainly came from anthropogenic sources in northern Xinjiang(PSCF values 0.5-0.8).(4)In 2023,four high-concentration PM10 events(peaks 681.1-822.6 μg·m-3)and five high-concentration PM2.5 events(peaks 294.2-551.4 μg·m-3)were observed,with durations typically less than one hour,exhibiting"short-term high-intensity"characteristics.(5)Compared with Lin'an station,PM10 and PM2.5 at Akedala showed"low baseline,high variability,and short peaks",with baseline values lower than Lin'an but higher peak concentrations.This study provides a scientific basis for understanding atmospheric background particulate matter in arid regions and analyzing transboundary transport patterns,supporting air quality assessment and regional collaborative governance in northwest China.