Nature and Magnitude of Atmospheric Fluxes of Total Inorganic Nitrogen and Other Inorganic Species to the Tampa Bay Watershed, FL, USA

Poor, N.; Pollman, C.; Tate, P.; Begum, M.; Evans, M.; Campbell, S.

Nature and Magnitude of Atmospheric Fluxes of Total Inorganic Nitrogen and Other Inorganic Species to the Tampa Bay Watershed, FL, USA

2006

We estimated the total inorganic fluxes of nitrogen (N), sulfur (S), chloride (Cl-, sodium (Na⁺, calcium (Ca²⁺, magnesium (Mg²⁺, potassium (K⁺ and hydronium (H⁺. The resistance deposition algorithm that is programmed as part of the CALMET/CALPUFF modeling system was used to generate spatially-distributed deposition velocities, which were then combined with measurements of urban and rural concentrations of gas and particle species to obtain dry deposition rates. Wet deposition rates for each species were determined from rainfall concentrations and amounts available from the National Acid Deposition Program (NADP) monitoring network databases. The estimated total inorganic nitrogen deposition to the Tampa Bay watershed (excluding Tampa Bay) was 17 kg-N ha-¹ yr-¹ or 9,700 metric tons yr-¹, and the ratio of dry to wet deposition rates was ~2.3 for inorganic nitrogen. The largest contributors to the total N flux were ammonia (NH₃ and nitrogen oxides (NO x at 4.6 kg-N ha-¹ yr-¹ and 5.1 kg-N ha-¹ yr-¹, respectively. Averaged wet deposition rates were 2.3 and 2.7 kg-N ha-¹ yr-¹ for NH₄ ⁺ and NO₃ -, respectively.

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