Based on ground-based remote sensing and sea-land breeze identification algorithms, researchers found that sea breezes and typhoons along Hainan Island's coast suppress photochemical reactions but transport ozone precursors to the area. Sea breezes largely confine pollutants below 300 m, while typhoons elevate pollution levels at mid-upper altitudes. These findings highlight that tropical coastal sea breezes and typhoons threaten air quality, necessitating targeted pollution mitigation policies.

A six-year study in a Shanghai port shows during low-sulfur fuel policies adjustment phase (2018–2020), ship pollution decreases by 43.47 % and 23.08 % yearly, but emissions rebounded 19.5 % yearly post-2020 as shipping grew. Using air sensors and data analysis, researchers identified cargo ships as key polluters and created a cost-effective monitoring method for global ports. Findings warn shipping expansion risks air quality progress, urging smarter policies while supporting trade.

In 2022, Shanghai implemented city-wide static management measures during the high-ozone season in April and May, providing a chance to study ozone pollution control. Despite significant emissions reductions, ozone levels increased by 23 %. Statistically, the number of days with higher ozone diurnal variation types increased during the lockdown period. The uneven decline in VOC and NO₂ emissions led to heightened photochemical processes, resulting in the observed ozone level rise.

Our tropospheric NO₂ vertical column density product with high spatiotemporal resolution is based on the Geostationary Environment Monitoring Spectrometer (GEMS) and named POMINO–GEMS. Strong hotspot signals and NO₂ diurnal variations are clearly seen. Validations with multiple satellite products and ground-based, mobile car and surface measurements exhibit the overall great performance of the POMINO–GEMS product, indicating its capability for application in environmental studies.

High RH could contribute to the secondary formation of HONO in the sea atmosphere. High temperature could promote the formation of HONO from NO₂ heterogeneous reactions in the sea and coastal atmosphere. The aerosol surface plays a more important role during the above process in coastal and sea cases. The generation rate of HONO from the NO₂ heterogeneous reaction in the sea cases is larger than that in inland cases in higher atmospheric layers above 600 m.