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dc.contributor.authorMcClelland, James W.  Concept link
dc.contributor.authorStieglitz, Marc  Concept link
dc.contributor.authorPan, Feifei  Concept link
dc.contributor.authorHolmes, Robert M.  Concept link
dc.contributor.authorPeterson, Bruce J.  Concept link
dc.date.accessioned2010-06-16T19:16:26Z
dc.date.available2010-06-16T19:16:26Z
dc.date.issued2007-11-08
dc.identifier.citationJournal of Geophysical Research 112 (2007): G04S60en_US
dc.identifier.urihttps://hdl.handle.net/1912/3661
dc.descriptionAuthor Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): G04S60, doi:10.1029/2006JG000371.en_US
dc.description.abstractExport of nitrate and dissolved organic carbon (DOC) from the upper Kuparuk River between the late 1970s and early 2000s was evaluated using long-term ecological research (LTER) data in combination with solute flux and catchment hydrology models. The USGS Load Estimator (LOADEST) was used to calculate June–August export from 1978 forward. LOADEST was then coupled with a catchment-based land surface model (CLSM) to estimate total annual export from 1991 to 2001. Simulations using the LOADEST/CLSM combination indicate that annual nitrate export from the upper Kuparuk River increased by ~5 fold and annual DOC export decreased by about one half from 1991 to 2001. The decrease in DOC export was focused in May and was primarily attributed to a decrease in river discharge. In contrast, increased nitrate export was evident from May to September and was primarily attributed to increased nitrate concentrations. Increased nitrate concentrations are evident across a wide range of discharge conditions, indicating that higher values do not simply reflect lower discharge in recent years but a significant shift to higher concentration per unit discharge. Nitrate concentrations remained elevated after 2001. However, extraordinarily low discharge during June 2004 and June–August 2005 outweighed the influence of higher concentrations in determining export during these years. The mechanism responsible for the recent increase in nitrate concentrations is uncertain but may relate to changes in soils and vegetation associated with regional warming. While changes in nitrate and DOC export from arctic rivers reflect changes in terrestrial ecosystems, they also have significant implications for Arctic Ocean ecosystems.en_US
dc.description.sponsorshipThis work was supported by the Arctic System Science Program of the National Science Foundation (OPP- 0436118) and by NSF funding for the Arctic LTER through a series of grants from 1987 to present.en_US
dc.format.mimetypeapplication/pdf
dc.language.isoen_USen_US
dc.publisherAmerican Geophysical Unionen_US
dc.relation.urihttps://doi.org/10.1029/2006JG000371
dc.subjectNitrateen_US
dc.subjectDOCen_US
dc.subjectArcticen_US
dc.subjectRiversen_US
dc.subjectChangeen_US
dc.titleRecent changes in nitrate and dissolved organic carbon export from the upper Kuparuk River, North Slope, Alaskaen_US
dc.typeArticleen_US
dc.identifier.doi10.1029/2006JG000371


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