The contribution of industrial emissions to ozone pollution: identified using ozone formation path tracing approach.

Wintertime meteorological conditions are usually unfavorable for ozone (O) formation due to weak solar irradiation and low temperature. Here, we observed a prominent wintertime O pollution event in Shijiazhuang (SJZ) during the Chinese New Year (CNY) in 2021. Meteorological results found that the sudden change in the air pressure field, leading to the wind changing from northwest before CNY to southwest during CNY, promotes the accumulation of air pollutants from southwest neighbor areas of SJZ and greatly inhibits the diffusion and dilution of local pollutants.

Anomalous surface O changes in North China Plain during the northwestward movement of a landing typhoon.

As high impact weather in a large scale, typhoon movement from the northwest Pacific into inland regions influencing ambient O changes is unclear, especially in North China Plain (NCP). A landing Typhoon Ampil during July 17-24, 2018 was studied herein to characterize the surface O anomalies during its movement over NCP. Landing typhoons present large negative O anomalies at the center of the typhoon and positive O anomalies 600-1700 km away from the center.

Influence of Chinese New Year overlapping COVID-19 lockdown on HONO sources in Shijiazhuang.

Nitrous acid (HONO) is an important precursor of hydroxyl radical (OH) in the atmosphere. It is also toxic to human health. In this work, HONO concentrations were measured in Shijiazhuang using a Monitor for AeRosols and Gases in ambient Air (MARGA) from December 15, 2019 to March 15, 2020, which covered the heavy air pollution season, the Chinese New Year (CNY) vocation and the Corona Virus Disease-19 (COVID-19) lockdown period.