Dry and wet deposition of inorganic nitrogen compounds to a tropical pasture site (Rondônia, Brazil)

Autor: Ivonne Trebs, Meinrat O. Andreae, Luciene L. Lara, Paulo Artaxo, Ralph Dlugi, Luciana V. Gatti, L. M. M. Zeri, Franz X. Meixner, J. Slanina
Přispěvatelé: Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, Centro de Energia Nuclear na Agricultura (CENA ), University of São Paulo (USP), Department Biogeochemical Processes [Jena], Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Instituto de Pesquisas Energéticas e Nucleares [São Paulo] (IPEN/CNEN-SP), Comissão National de Energia Nuclear (CNEN)-Universidade de São Paulo (USP), Instituto de Física, Universidade de São Paulo (USP), Working Group Atmospheric Processes (WAP), Peking University [Beijing], Laboratorio de Ecologia Isotopica, Centro de Energia Nuclear na Agricultura (CENA), Universidade de São Paulo (USP)-Comissão National de Energia Nuclear (CNEN), Instituto de Fisica, Department of Environmental Sciences, Wageningen University and Research [Wageningen] (WUR)
Rok vydání: 2006
Předmět:
Zdroj: ResearcherID
Atmospheric Chemistry and Physics
Atmospheric Chemistry and Physics, European Geosciences Union, 2006, 6 (2), pp.447-469
Atmospheric Chemistry and Physics Discussions
Atmospheric Chemistry and Physics Discussions, European Geosciences Union, 2005, 5 (3), pp.3131-3189
Atmospheric Chemistry and Physics, Vol 6, Iss 2, Pp 447-469 (2006)
Scopus-Elsevier
ISSN: 1680-7324
1680-7316
1680-7367
1680-7375
DOI: 10.5194/acp-6-447-2006
Popis: The input of nitrogen (N) to ecosystems has increased dramatically over the past decades. While total (wet+dry) N deposition has been extensively determined in temperate regions, only very few data sets of N wet deposition exist for tropical ecosystems, and moreover, reliable experimental information about N dry deposition in tropical environments is lacking. In this study we estimate dry and wet deposition of inorganic N for a remote pasture site in the Amazon Basin based on in-situ measurements. The measurements covered the late dry (biomass burning) season, a transition period and the onset of the wet season (clean conditions) (12 September to 14 November 2002) and were a part of the LBA-SMOCC (Large-Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall, and Climate) 2002 campaign. Ammonia (NH3), nitric acid (HNO3), nitrous acid (HONO), nitrogen dioxide (NO2), nitric oxide (NO), ozone (O3), aerosol ammonium (NH4+) and aerosol nitrate (NO3-) were measured in real-time, accompanied by simultaneous meteorological measurements. Dry deposition fluxes of NO2 and HNO3 are inferred using the ''big leaf multiple resistance approach'' and particle deposition fluxes are derived using an established empirical parameterization. Bi-directional surface-atmosphere exchange fluxes of NH3 and HONO are estimated by applying a ''canopy compensation point model''. N dry and wet deposition is dominated by NH3 and NH4+, which is largely the consequence of biomass burning during the dry season. The grass surface appeared to have a strong potential for daytime NH3 emission, owing to high canopy compensation points, which are related to high surface temperatures and to direct NH3 emissions from cattle excreta. NO2 also significantly accounted for N dry deposition, whereas HNO3, HONO and N-containing aerosol species were only minor contributors. Ignoring NH3 emission from the vegetation surface, the annual net N deposition rate is estimated to be about −11 kgN ha-1 yr-1. If on the other hand, surface-atmosphere exchange of NH3 is considered to be bi-directional, the annual net N budget at the pasture site is estimated to range from −2.15 to −4.25 kgN ha-1 yr-1.
Databáze: OpenAIRE
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