The application of inverse-dispersion and gradient methods to estimate ammonia emissions from a penguin colony

• Published in: Atmospheric environment (1994) Vol. 81; pp. 320 - 329
• Main Authors: Theobald, Mark R., Crittenden, Peter D., Tang, Y. Sim, Sutton, Mark A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-12-2013; Elsevier
• Subjects: Ammonia emissions; Analysis methods; Applied sciences; Atmospheric pollution; Exact sciences and technology; Inverse-dispersion modelling; Marine; Nitrogen; Penguins; Pollution; Seabirds; Antarctica; PS, Antarctica; Ammonia emissions; Seabirds; Inverse-dispersion modelling; Nitrogen; Penguins; Uncertainty; Nitrogen compounds; Pygoscelis adeliae; Emission inventory; Ammonia; Vertebrata; Air biosphere interaction; Micrometeorology; Pollution source; Colony; Air pollution; Poison; Models; Polar region; Atmospheric dispersion; Measurement method; Aves; Computing method; Gradient method
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2013.09.009

Penguin colonies represent some of the most concentrated sources of ammonia emissions to the atmosphere in the world. The ammonia emitted into the atmosphere can have a large influence on the nitrogen cycling of ecosystems near the colonies. However, despite the ecological importance of the emissions, no measurements of ammonia emissions from penguin colonies have been made. The objective of this work was to determine the ammonia emission rate of a penguin colony using inverse-dispersion modelling and gradient methods. We measured meteorological variables and mean atmospheric concentrations of ammonia at seven locations near a colony of Adélie penguins in Antarctica to provide input data for inverse-dispersion modelling. Three different atmospheric dispersion models (ADMS, LADD and a Lagrangian stochastic model) were used to provide a robust emission estimate. The Lagrangian stochastic model was applied both in ‘forwards’ and ‘backwards’ mode to compare the difference between the two approaches. In addition, the aerodynamic gradient method was applied using vertical profiles of mean ammonia concentrations measured near the centre of the colony. The emission estimates derived from the simulations of the three dispersion models and the aerodynamic gradient method agreed quite well, giving a mean emission of 1.1 g ammonia per breeding pair per day (95% confidence interval: 0.4–2.5 g ammonia per breeding pair per day). This emission rate represents a volatilisation of 1.9% of the estimated nitrogen excretion of the penguins, which agrees well with that estimated from a temperature-dependent bioenergetics model. We found that, in this study, the Lagrangian stochastic model seemed to give more reliable emission estimates in ‘forwards’ mode than in ‘backwards’ mode due to the assumptions made.
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•We measure atmospheric ammonia concentrations at locations around a penguin colony.•We estimate ammonia emission rates using inverse modelling and gradient methods.•Mean ammonia emissions are estimated to be 1.1 g ammonia per breeding pair per day.•We estimate that 2% of the nitrogen excreted by the penguins is emitted as ammonia.