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    • Global N Cycle: Fluxes and N2O Mixing Ratios Originating from Human Activity

    Metadata Updated: December 7, 2023

    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.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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    Dates

    Metadata Created Date October 11, 2023
    Metadata Updated Date December 7, 2023

    Metadata Source

    Harvested from NASA Data.json

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    Additional Metadata

    Resource Type Dataset
    Metadata Created Date October 11, 2023
    Metadata Updated Date December 7, 2023
    Publisher ORNL_DAAC
    Maintainer
    Identifier C2776893351-ORNL_CLOUD
    Data First Published 2023-10-02
    Language en-US
    Data Last Modified 2023-10-03
    Category Climate, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Metadata Catalog ID https://data.nasa.gov/data.json
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Citation Holland, E.A., J. Lee-Taylor, C. Nevison, and J.M. Sulzman. 2005. Global N Cycle: Fluxes and N2O Mixing Ratios Originating from Human Activity. ORNL DAAC, Oak Ridge, Tennessee, USA. http://dx.doi.org/10.3334/ORNLDAAC/797
    Graphic Preview Description Browse Image
    Graphic Preview File https://daac.ornl.gov/graphics/browse/project/square/climate_logo_square.png
    Harvest Object Id a66ba532-200d-413c-8c78-3e11b7c236a4
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://doi.org/10.3334/ORNLDAAC/797
    Metadata Type geospatial
    Old Spatial -180.0 -90.0 180.0 90.0
    Program Code 026:001
    Source Datajson Identifier True
    Source Hash fad462975d414014ad4bafda88083043cfccbf35a7056812b3bb8064ef02d131
    Source Schema Version 1.1
    Spatial
    Temporal 1756-01-01T00:00:00Z/2004-12-31T23:59:59Z

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