Climate change and dissolved organic carbon export to the Gulf of Maine
Climate change and dissolved organic carbon export to the Gulf of Maine
Ongoing climate change is affecting the concentration, export (flux), and timing of dissolved organic carbon (DOC) exported to the Gulf of Maine (GoM) through changes in hydrologic regime. DOC export was calculated for water years 1950 through 2013 for 20 rivers and for water years 1930 through 2013 for 14 rivers draining to the GoM. DOC export was also estimated for the 21st century based on climate and hydrologic modeling in a previously published study. DOC export was calculated by using the regression model LOADEST to fit seasonally adjusted concentration discharge (C-Q) relations. Our results are an analysis of the sensitivity of DOC export to changes in hydrologic conditions over time since land cover and vegetation were held constant over time. Despite large interannual variability, all rivers had increasing DOC export during winter and these trends were significant (p < 0.05) in 10 out of 20 rivers for 1950 to 2013 and in 13 out of 14 rivers for 1930 to 2013. All rivers also had increasing annual export of DOC although fewer trends were statistically significant than for winter export. Projections for DOC export during the 21st century were variable depending on the climate model and greenhouse gas emission scenario that affected future river discharge through effects on precipitation and evapotranspiration. The most consistent result was a significant increase in DOC export in winter in all model-by-emission scenarios. DOC export was projected to decrease during the summer in all model-by-emission scenarios, with statistically significant decreases in half of the scenarios.
carbon cycling, climate impacts on water quality, dissolved organic carbon, Gulf of Maine
2700-2716
Huntington, Thomas G.
e2b2f6a9-f2bf-4b03-9a01-07afd4507332
Balch, William M.
18270567-fc45-4bc9-bd82-253d473e9564
Aiken, George R.
56607502-2015-4e2c-848b-4623b6f928ad
Sheffield, Justin
dd66575b-a4dc-4190-ad95-df2d6aaaaa6b
Luo, Lifeng
e9b25aa8-e877-45a6-bdca-53aba9bbde84
Roesler, Collin S.
d63c2b28-6f32-4994-a5fd-a1f67c328ad0
Camill, Philip
05fd302f-149d-4fc8-a3a4-8a215d623b6b
1 October 2016
Huntington, Thomas G.
e2b2f6a9-f2bf-4b03-9a01-07afd4507332
Balch, William M.
18270567-fc45-4bc9-bd82-253d473e9564
Aiken, George R.
56607502-2015-4e2c-848b-4623b6f928ad
Sheffield, Justin
dd66575b-a4dc-4190-ad95-df2d6aaaaa6b
Luo, Lifeng
e9b25aa8-e877-45a6-bdca-53aba9bbde84
Roesler, Collin S.
d63c2b28-6f32-4994-a5fd-a1f67c328ad0
Camill, Philip
05fd302f-149d-4fc8-a3a4-8a215d623b6b
Huntington, Thomas G., Balch, William M., Aiken, George R. and Sheffield, Justin
,
et al.
(2016)
Climate change and dissolved organic carbon export to the Gulf of Maine.
Journal of Geophysical Research: Biogeosciences, 121 (10), .
(doi:10.1002/2015JG003314).
Abstract
Ongoing climate change is affecting the concentration, export (flux), and timing of dissolved organic carbon (DOC) exported to the Gulf of Maine (GoM) through changes in hydrologic regime. DOC export was calculated for water years 1950 through 2013 for 20 rivers and for water years 1930 through 2013 for 14 rivers draining to the GoM. DOC export was also estimated for the 21st century based on climate and hydrologic modeling in a previously published study. DOC export was calculated by using the regression model LOADEST to fit seasonally adjusted concentration discharge (C-Q) relations. Our results are an analysis of the sensitivity of DOC export to changes in hydrologic conditions over time since land cover and vegetation were held constant over time. Despite large interannual variability, all rivers had increasing DOC export during winter and these trends were significant (p < 0.05) in 10 out of 20 rivers for 1950 to 2013 and in 13 out of 14 rivers for 1930 to 2013. All rivers also had increasing annual export of DOC although fewer trends were statistically significant than for winter export. Projections for DOC export during the 21st century were variable depending on the climate model and greenhouse gas emission scenario that affected future river discharge through effects on precipitation and evapotranspiration. The most consistent result was a significant increase in DOC export in winter in all model-by-emission scenarios. DOC export was projected to decrease during the summer in all model-by-emission scenarios, with statistically significant decreases in half of the scenarios.
This record has no associated files available for download.
More information
Accepted/In Press date: 25 September 2016
Published date: 1 October 2016
Additional Information:
Funding Information:
The historical hydrologic data used in this study are available from the U.S. Geological Survey NWIS database (10.5066/F7P55KJN). The 21st century hydrologic data are available from the corresponding author. The DOC data collected by the USGS are available from the U.S. Geological Survey NWIS database (10.5066/F7P55KJN), and the data collected by Bowdoin College are available from the NASA SeaBass archive (http://seabass.gsfc.nasa.gov/seabasscgi/archive.cgi?q=BOWDOIN/camill/3rivers/archive). This work was supported by NASA grants NNYH04AA661 and NNH08A1571 and the U.S. Geological Survey funds for climate research. W.M.B. was supported by NASA grants NNX11AQ70G and NNX14AM77G. We thank hydrologic technicians with the USGS Water Science Center in Augusta, Maine, for their support in the maintenance of discharge records and their assistance with sampling, and we thank Kenna Butler, chemist with the USGS, for her assistance with chemical analysis and database management. We also thank Anna Bourakovsky and students of Bowdoin College for the sampling and analysis of water samples from several of the rivers included in this study. We thank Robert Runkel (USGS, Boulder, CO) and Timothy Cohn (USGS, Reston, VA) for the assistance with the application of the LOADEST model. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the USGS.
Publisher Copyright:
©2016. American Geophysical Union. All Rights Reserved.
Keywords:
carbon cycling, climate impacts on water quality, dissolved organic carbon, Gulf of Maine
Identifiers
Local EPrints ID: 476649
URI: http://eprints.soton.ac.uk/id/eprint/476649
ISSN: 2169-8953
PURE UUID: bd44e463-db0c-4ca8-a8c3-158b95c64776
Catalogue record
Date deposited: 10 May 2023 17:07
Last modified: 18 Mar 2024 03:33
Export record
Altmetrics
Contributors
Author:
Thomas G. Huntington
Author:
William M. Balch
Author:
George R. Aiken
Author:
Lifeng Luo
Author:
Collin S. Roesler
Author:
Philip Camill
Corporate Author: et al.
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics
