The influence of emission changes on ozone concentrations and nitrogen deposition into the southern North Sea

• Published in: Meteorologische Zeitschrift (Berlin, Germany : 1992) Vol. 20; no. 1; pp. 75 - 84
• Main Authors: Elke M.I. Meyer, K. Heinke Schlünzen
• Format: Journal Article
• Language: English
• Published: Borntraeger 01.02.2011
• ISSN: 0941-2948
• DOI: 10.1127/0941-2948/2011/0489

The impact of changes in amount of emission for NOx (Nitrogen monoxide NO + Nitrogen dioxide NO2) and NMVOC (Non Methane Volatile Organic Compounds) on concentrations of ozone (O3), NOx, nitric acid (HNO3) and on nitrogen deposition in the area of the southern North Sea are investigated. One reference case for the period 16 June till 20 June, 1998 and six emission scenarios are calculated. Spatial and temporal emission patterns are kept and overall emission factors are used that correspond to years 1998 (reference), 1970 and 2010. Some more artificial emission scenarios are constructed to investigate the effect of a changed ratio of NOx to NMVOC emissions. The meteorology is unchanged for all scenarios. The studies are performed with the meteorology/chemistry model M-SYS (METRAS/MECTM) including a simple aerosol chemistry and using a horizontal resolution of 8 km. Changes in emissions of NMVOC and NOx cause nonlinear changes in O3, NOx and HNO3 concentrations. The concentration changes depend on emission changes and on changes in the ratio of NMVOC to NOx emissions. The whole area, over land and water, turns out to be in the NMVOC limited regime. Ozone scenario concentrations linearly depend on the ratio of NMVOC to NOx emissions. NOx concentrations linearly depend on changes in the total emissions of NOx and NMVOC. They are inversely related to changes in the ratio of NMVOC to NOx emissions. HNO3 concentrations mainly depend on the total emission changes with NOx emission changes being of doubled relevance compared to NMVOC emission changes. The same relation is found for nitrogen deposition. Compared to mean ozone concentrations from the reference case, higher (lower) NOx emissions reduce (increase) ozone concentrations, while HNO3 concentrations are increased (reduced). In contrast, reduced (increased) NMVOC emissions reduce (increase) both, ozone and HNO3 concentrations and, in addition, the nitrogen deposition.