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Climate change and dissolved organic carbon export to the Gulf of Maine
Author(s) -
Huntington Thomas G.,
Balch William M.,
Aiken George R.,
Sheffield Justin,
Luo Lifeng,
Roesler Collin S.,
Camill Philip
Publication year - 2016
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
eISSN - 2169-8961
pISSN - 2169-8953
DOI - 10.1002/2015jg003314
Subject(s) - dissolved organic carbon , environmental science , evapotranspiration , climate change , precipitation , greenhouse gas , hydrology (agriculture) , water discharge , discharge , representative concentration pathways , climate model , oceanography , drainage basin , geography , geology , ecology , meteorology , geotechnical engineering , cartography , biology
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.