Determination of weather-driven trends of atmospheric emissions, concentrations and deposition over Europe during the last decades

Abstract. The dependency of emission and atmospheric physicochemical processes on various meteorological drivers are often not completely accounted for by 3D air quality models. In order to tackle this issue, the present study assesses weather-driven trends in atmospheric emissions and air quality in Europe over 1990–2022 using an enhanced version of the CHIMERE chemical transport model. The model includes meteorology-dependent anthropogenic emissions, varying 8-day leaf area index from satellite data over the whole period, and updated parameterizations for deposition as well as soil and biogenic emissions.

Simulations performed with constant anthropogenic emission practices indicate significant increases in biogenic VOC, ammonia, and soil NOx emissions. In contrast, emissions decrease for the residential sector and road traffic NOx, due to warmer temperatures reducing heating and cold-start emissions.

Ozone annual concentrations show regionally contrasting trends, with increases in southern Europe but decreases in northern regions due to enhanced deposition linked to vegetation changes. Significant increases, driven mainly by rising temperatures and solar radiation, are simulated for SOMO35 and AOT40c, with population-weighted trends of 0.5 %/yr and 0.69 %/yr, corresponding to overall increases by 18 % and 22 % over the 1990–2022 period, respectively. Fine particulate matter generally declines (population-weighted trend of -0.03 µg/m³/yr, +0.95 µg/m³/yr over the period), despite increases in secondary organic aerosols and bioaerosols. Reduced nitrogen deposition also increased (+3.9 kT/yr, around +4.8 % over the period) due to increases in ammonia gas-phase fraction and emissions.