Estimation of dry deposition of atmospheric nitrogen to coastal waters of de la Plata River in front of Buenos Aires city

Abstract

The deposition of atmospheric nitrogen (N) to surface waters of de la Plata River downwind of Buenos Aires city has been estimated using atmospheric dispersion-deposition models. The CALPUFF model has been applied to point source emissions and the DAUMOD-RD model has been developed to evaluate the area source emission contributions. Annual N dry deposition is 31,763 kg-N yr−1 (≈ 18 kg-N km−2 yr−1). Nitrogen dioxide contribution to this value is 54% and nitric acid contribution is 46%. The maximum monthly N dry deposition fluxes vary between 7 kg-N km−2 month−1 (in February) and 13 kg-N km−2 month−1 (in December).