Analysis on impact of sand and dust weather on air pollution in Langfang

ZHANG Xinmu; XU Min; LIU Qiqi

doi:10.19513/j.cnki.hyqxxb.20250106001

Abstract：Based on the surface meteorological data of Langfang National Meteorological Observing Station and the particulate matter mass concentration and AQI(air quality index)data of Langfang Municipal Bureau of Ecology and Environment,the characteristics of the air pollution in Langfang from 1 December 2020 to 30 November 2023 are analyzed.The results are outlined below.(1)Of the sand and dust weather in Langfang,72.7％(8/11)can cause a significant increase by over 80 in AQI,and 88.9％of the severe pollution days occur under the influence of sand and dust weather,mostly in spring.(2)The sand and dust processes on 15 March 2021 and 10-13 April 2023 belong to the upstream transmission type with strong intensity and long duration.The mass concentrations of PM2.5 and PM10 generally show a trend of rising and falling together,and the occurrence of sand and dust lags behind the occurrence of strong winds.(3)The sand and dust process on 4 March 2022 belongs to the locally generated type,characterized by weak intensity,small impact range and short duration.At the same time,the change in the concentration of PM10 lags behind that of PM2.5,and the mass concentration of PM2.5 drops sharply when the concentration of PM10 suddenly rises.The sharp increase in the mass concentration of PM10 almost occurs synchronously with strong winds.(4)The analysis on the three typical sand and dust weather processes shows that the ratio between PM2.5 and PM10 corresponds well with the generation and dissipation of sand and dust.(5)A higher wind speed is beneficial for the formation of sand and dust weather,while when the wind speed is excessively high,it will hinder the settling of sand and dust particles.The pollutants brought in by the northerly and southwesterly winds have a greater impact on the air pollution in Langfang.