Modeling the regional impact of ship emissions on NOx and ozone levels over the EasternAtlantic and Western Europe using ship plume parameterization
Abstract
Chemistry transport models normally apply instantaneous mixing of emissions into the model's finest resolved scale, resulting often in erroneous calculation of concentrations. This study deals with these non-linear effects during dispersion of NOx emissions from ships.
We found that the contribution of ship induced surface NOx to the total reaches 90% over remote ocean and makes 10–30% near coastal regions. Due to ship emissions, surface ozone increases by up to 4–6 ppbv making 10% contribution to the surface ozone budget.With the ship plume parameterization, the large scale NOx decreases and the ship NOx contribution is reduced by up to 20–25%.
A decrease was found in the case of O3 as well. The plume parameterization suppressed the ship ozone production by 15–30%.
Nitrogen monoxide measurements were compared with modeled values showing increase in model accuracy with activated parameterization.