Characteristics and Meteorological Factors of Severe Haze Pollution in China

A severe haze pollution incident caused by unfavorable weather conditions and a northern air mass occurred in eastern, northern, northwestern, southwestern China from January 15 to 22, 2018. To comparatively analyze variations PM2.5 pollution, hourly monitoring data 24 h meteorological were collected. Air quality observations revealed large spatiotemporal variation concentrations Handan, Zhengzhou, Xi’an, Yuncheng, Chengdu, Xiangyang, Jinan. The daily mean ranged 111.35 227.23 μg·m−³, with concentration being highest Zhengzhou. Hourly presented multiple U-shaped curves, higher values at night lower during the day. ratios of PM10 target cities results multiscale geographic weighted regression model (MGWR) Pearson correlation coefficients showed that had significant positive or negative PM10, CO, NO2, SO2. was closely related combustion fossil fuels other organic compounds, indicating contribution secondary aerosols concentrations. analysis low temperature, wind speed, high relative humidity could aggravate accumulation regional pollutants winter. Northwestern trajectory clusters predominant contributions except Jinan, associated short potential sources calculated Weight Potential Source Contribution Function (WPSCF) Concentration-Weighted Trajectory (WCWT) models similar WPSCF (>0.5) WCWT (>100 μg·m−³) mainly distributed densely populated, industrial, arid, semiarid regions.