GLOBAL N CYCLE: FLUXES AND N2O MIXING RATIOS ORIGINATING FROM HUMAN ACTIVITYEntry ID: global_n_cycle
Abstract: Nitrogen is a major nutrient in terrestrial ecosystems and an important catalyst in tropospheric photochemistry. Over the last century human activities have dramatically increased inputs of reactive nitrogen (Nr, the combination of oxidized, reduced and organically bound nitrogen) to the Earth system. Nitrogen cycle perturbations have compromised air quality and human health, acidified ecosystems, ... and degraded and eutrophied lakes and coastal estuaries [Vitousek et al., 1997a, 1997b; Rabalais, 2002; Howarth et al., 2003; Townsend et al., 2003; Galloway et al., 2004]. To begin to quantify the changes to the global N cycle, we have assembled key flux data and N2O mixing ratios from various sources. The data assembled from different sources includes fertilizer production from 1920-2004; manure production from 1860-2004; crop N fixation estimated for three time points, 1860, 1900, 1995; tropospheric N2O mixing ratios from ice core and firn measurements, and tropospheric concentrations to cover the time period from 1756-2004. The changing N2O concentrations provide an independent index of changes to the global N cycle, in much the same way that changing carbon dioxide concentrations provide an important constraint on the global carbon cycle. The changes to the global N cycle are driven by industrialization, as indicated by fossil fuel NOx emission, and by the intensification of agriculture, as indicted by fertilizer and manure production and crop N2 fixation. The data set and the science it reflects are by nature interdisciplinary. Making the data set available through the ORNL DAAC is an attempt to make the data set available to the considerable interdisciplinary community studying the N cycle.
Data Set Citation
Dataset Originator/Creator: HOLLAND, E.A.LEE-TAYLOR, J.NEVISON, C.SULZMAN, J.M.
Dataset Title: GLOBAL N CYCLE: FLUXES AND N2O MIXING RATIOS ORIGINATING FROM HUMAN ACTIVITY
Dataset Release Date: 2005
Dataset Release Place: Oak Ridge, Tennessee, U.S.A.
Dataset Publisher: Oak Ridge National Laboratory Distributed Active Archive Center
Data Presentation Form: Online Files
Dataset DOI: doi:10.3334/ORNLDAAC/797Online Resource: http://mercury.ornl.gov/ornldaac/send/query?term2=797&term2attribut...
Start Date: 1756-01-01Stop Date: 2004-12-31
Data Set Progress
Role: TECHNICAL CONTACT
Email: eholland at acd.ucar.edu
Email: eholland at ucar.edu
Atmospheric Chemistry Division National Center for Atmospheric Research 1850 Table Mesa Drive
Province or State: CO
Postal Code: 80305
Role: DIF AUTHOR
Phone: (865) 574-7447
Email: uso at daac.ornl.gov
ORNL DAAC User Services Office Oak Ridge National Laboratory
City: Oak Ridge
Province or State: TN
Postal Code: 37831-6407
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2005-07-18
Last DIF Revision Date: 2012-05-23