乌鲁木齐市大气降水化学与湿沉降的城郊时空分异特征OA

This study synchronously collected rainfall and snow samples at 3 urban and 3 suburban sites in Urumqi from January to December 2024,analyzed the monthly variations of pH,water-soluble ion concentra-tions and wet deposition fluxes,and conducted source apportionment using the PMF model.The results showed that:(1)precipitation was alkaline,with Ca2+,Na+,SO42-and Cl-as the dominant ions,accounting for over 70%of the total ion concentration;(2)wet deposition fluxes in both urban and suburban areas were predominantly con-trolled by precipitation amount,while Na+,F−,Mg2+and K+fluxes in the urban area were also significantly influ-enced by ion concentrations,reflecting the superimposed effect of intensive pollution sources in the urban area;(3)PMF analysis indicated that a 4-factor model was applicable for the urban area and a 5-factor model was ap-plicable for the suburban area;secondary inorganic aerosols contributed 73.46%in urban rainfall,while saline-al-kali dust sources contributed 25.85%in suburban rainfall,with agricultural ammonia emission sources identified,and an independent snow-melting agent influence source identified in suburban snowfall;(4)secondary inorganic aerosols in suburban snowfall were split into nitrate-dominant and sulfate-sodium salt mixed factors,while mixed-type structures were observed in all rainfall conditions.The allocation characteristics of F-revealed industrial lay-out differences between secondary transformation of fluorine-containing emissions from light industry in the ur-ban area and direct emissions from heavy industry in the suburban area.