Estimating emissions of greenhouse gases such as methane for individual countries is fundamental for climate mitigation policies. Numerical models can simulate how such emissions are transported to observation sites. Based on the observations, one can estimate the emissions. We describe how operational numerical weather prediction can help determine the model uncertainties and thereby improve the emission estimates. We test our system using simulated observations.

Estimating emissions of greenhouse gases such as methane for individual countries is fundamental for climate mitigation policies. We use a numerical weather model to simulate how methane emissions are transported to observation sites. Based on the observations, we estimate the emissions in Central Europe in 2021. For Germany and the Benelux, we find higher emissions than expected from the national emission reporting. We provide sector-specific estimates to support national emission reporting.

Ecosystem-scale emissions of biogenic volatile organic compounds (BVOCs) are important for atmospheric chemistry. Here we investigate boreal BVOC fluxes from a forest in central Sweden. BVOC fluxes were measured above-canopy using proton-transfer-reaction mass spectrometry, while compound-specific monoterpene (MT) fluxes were assessed using a concentration gradient method. We also evaluate the impact of chemical degradation on observed sesquiterpene (SQT) and nighttime MT fluxes.

Collisions of neutral molecules and clusters comprise the prevalent pathway in atmospheric new particle formation. In heavily polluted urban areas, where clusters are formed rapidly and in large numbers, cluster–cluster collisions also become relevant. We calculate cluster–cluster collision rates from atomistic molecular dynamics simulations and an interacting hard-sphere model. Not accounting for long-range attractive interactions underestimates collision and particle formation rates significantly.