title: Nitrogen deposition along differently exposed slopes in the Bavarian Alps.
abstract: The Alps are affected by high nitrogen deposition, particularly in the fringe of the Northern and Southern Alps. In the framework of a two-year monitoring study performed in 2010 and 2011, we investigated the ammonia and nitrogen dioxide air concentration and ammonium and nitrate deposition at different altitudes between 700 and 1,600 ma.s.l. in the Garmisch-Partenkirchen district in the Upper Bavaria region (Germany). Four-weekly measurements of deposition collected with bulk open field samplers and under-crown were performed in a profile perpendicular to the axis of the Loisach valley; measurements were conducted at eight sites. Whereas open field deposition ranged from 5 to 11 kg ha(-1)a(-1), nitrogen throughfall has reached up to 21 kg ha(-1)a(-1). Data from the valley and the slopes were compared with measurements performed on the platform of the Environmental Research Station Schneefernerhaus (Zugspitze) at an altitude of 2,650 ma.s.l. For the rough estimation of the total yearly deposition rate of nitrogen, the canopy uptake model was applied. By regarding nitrogen uptake by the trees, total deposition can exceed the throughfall in all sites by up to 50%. Additionally, we estimated the total deposition from the sum of wet and dry deposition. On the one side, the wet deposition could be extrapolated from the open field deposition. On the other side, we used the inferential method to calculate the dry deposition on the basis of NH3 and NO2 air concentrations and their literature based deposition velocities. Since fixed deposition velocities are inappropriate particularly in complex orography, we tried to find correction factors based upon terrain characteristics and meteorological considerations. Temperature monitoring at the eight sites and wind measurements at two sites provided some evidence for the semi-empirical parameterization. Due to numerous imponderabilities, the results of the two methods were not consistent for all sites.
authors.affiliation: Helmholtz Zentrum München, Cooperation Group "Comprehensive Molecular Analytics", Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: kirchner@helmholtz-muenchen.de.
authors.forename: Manfred
authors.initials: M
authors.lastname: Kirchner
authors.affiliation: Helmholtz Zentrum München, Cooperation Group "Comprehensive Molecular Analytics", Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: wolfgang.fegg@helmholtz-muenchen.de.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Fegg
authors.affiliation: ROE LABOR GmbH Umweltanalytik, Adlerstr. 11a, D-82166 Gräfelfing, Germany. Electronic address: ROE-Labor@t-online.de.
authors.forename: Horst
authors.initials: H
authors.lastname: Römmelt
authors.affiliation: Technische Universität München, Chair of Ecoclimatology, Hans-Carl-von-Carlowitz-Platz 2, D-85354 Freising, Germany. Electronic address: leuchner@wzw.tum.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Leuchner
authors.affiliation: Umweltbundesamt, GAW Globalstation Zugspitze/Hohenpeissenberg, Zugspitze 5, D-82475 Zugspitze, Germany. Electronic address: ludwig.ries@uba.de.
authors.forename: Ludwig
authors.initials: L
authors.lastname: Ries
authors.affiliation: Helmholtz Zentrum München, Cooperation Group "Comprehensive Molecular Analytics", Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: ralf.zimmermann@helmholtz-muenchen.de.
authors.forename: Ralf
authors.initials: R
authors.lastname: Zimmermann
authors.affiliation: Helmholtz Zentrum München, Molecular BioGeoChemistry and Analytics - BioGeomics, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: bernhard.michalke@helmholtz-muenchen.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Michalke
authors.affiliation: Umweltbundesamt, Messnetzzentrale Langen, Paul-Ehrlich-Straße 29, D-63225 Langen, Germany. Electronic address: markus.wallasch@uba.de.
authors.forename: Markus
authors.initials: M
authors.lastname: Wallasch
authors.affiliation: Helmholtz Zentrum München, Cooperation Group "Comprehensive Molecular Analytics", Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: maguhn@helmholtz-muenchen.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Maguhn
authors.affiliation: Helmholtz Zentrum München, Institute of Developmental Genetics, Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: faus@helmholtz-muenchen.de.
authors.forename: Theresa
authors.initials: T
authors.lastname: Faus-Kessler
authors.affiliation: Helmholtz Zentrum München, Cooperation Group "Comprehensive Molecular Analytics", Ingolstaedter Landstrasse 1, D-85764 Neuherberg, Germany. Electronic address: jakobi@helmholtz-muenchen.de.
authors.forename: Gert
authors.initials: G
authors.lastname: Jakobi
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D000531:Altitude; D017753:Ecosystem; D004784:Environmental Monitoring; D005858:Germany; D009584:Nitrogen / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D012989:Soil Pollutants; D009584:Nitrogen
keywords: Alps; Nitrogen; Spruce forest; Throughfall deposition; Vertical profiles