DRY and BULK atmospheric nitrogen deposition to a West-African humid forest exposed to terrestrial and oceanic sources

摘要: Abstract Atmospheric deposition can be a significant source of reactive nitrogen (Nr) in terrestrial ecosystems and might play relevant role for both N cycle processes C interactions. However, detailed studies annual budgets Nr are scarce many regions the globe, particularly dry depositions tropical areas. In this study we estimated magnitude dynamics bulk to an African humid forest located 30 km from Atlantic coast, National Park Ankasa (Ghana). concentrations gaseous (NH 3 , NO 2 HNO ) aerosol 4 + − compounds were measured above canopy, at 45 m, using active denuder filter sampling systems (DELTA). The experimental facility also provided high frequency micrometeorological data, sampled same height as DELTA, which used estimate fluxes gas aerosols by applying ensemble four inferential models (six NH ). Additionally, rates ionic composition determined. Estimated input site was −4.9 ± 1.7 kg Nr ha −1  yr 50% form  + NO Bulk accounted 23.1 ± 3.6 kg Nr ha . Two main peaks identified during year, first occurring season being more evident compounds, second wet season, when reached their maximum value. Savannah burning ocean emissions hypothesized two important sources Ankasa, former having latter dominating season. oceanic supported continuous site, consistent with constant presence sea breeze, causing never less than dominant wind direction over whole year.