Estimating the characteristics of atmospheric P deposition is critical to understanding the biogeochemical P cycle. Here we chose a typical urban–rural transition to monitor the dry and wet P depositions for 2 years. We found that atmospheric dry P deposition was the primary form of total P deposition, and P deposition could be affected by both meteorological factors and land-use types. Findings provide proper management of land use, which may help mitigate the pollution caused by P deposition.

HO₂ radicals play key roles in tropospheric chemistry, their levels in ambient air not yet fully explained by sophisticated models. Here we measured HO₂ uptake kinetics onto ambient aerosols in real time using a self-built online system and investigated the impacting factors on such processes by coupling with other instrumentations. The role of the HO₂ uptake process in O₃ formation is also discussed. Results give useful information for coordinated control of aerosol and ozone pollutants.

The present study examines the role of tropical cyclones in the enhancement of tropospheric ozone. The most significant and new observation reported is the increase in the upper-tropospheric ozone by 20–50 ppbv, which has extended down to the middle and lower troposphere. The descent rate of enhanced ozone layer during the passage of tropical cyclone is 0.8–1 km day⁻¹. Enhancement of surface ozone concentration by ~ 10 ppbv in the daytime and 10–15 ppbv at night-time is observed.

We show the first mercury profile measurements over Europe since 1996. Besides gaseous elemental mercury (GEM) and total gaseous mercury (TGM), the gases CO, SO₂, NO_x, and O₃ were measured from aboard a research aircraft over four European locations. Compared to the boundary layer, the concentration of GEM and TGM in the free troposphere was 10–30% lower. Inside the individual layers no vertical gradient was apparent. Combined with CARIBIC data, a unique profile from 0.4 to 10.5 km is provided.