Quantification of Discharge-Specific Effects on Dissolved Organic Matter Export From Major Arctic Rivers From 1982 Through 2019 ...

• Main Authors: Clark, Blake, Mannino, Antonio, Spencer, Robert G. M., Tank, Suzanne E., McClelland, James W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: AGU 2023
• Subjects: Arctic; Yukon
• Online Access: https://dx.doi.org/10.13016/m2ujmq-nkqi; https://mdsoar.org/handle/11603/29529

Long-term increases in Arctic river discharge have been well documented, and observations in the six largest Arctic rivers show strong positive correlations between dissolved organic carbon (DOC) concentration, river discharge, and chromophoric dissolved organic matter (CDOM) content. Here, observations of DOC and CDOM collected from 2009 to 2019 by the Arctic Great Rivers Observatory were used to estimate chromophoric DOC (CDOC) concentrations in the Kolyma, Lena, Mackenzie, Ob', Yenisey, and Yukon Rivers. All rivers except the Mackenzie showed significant positive correlations between annual watershed runoff and the proportion of the DOC that is chromophoric. Historical estimates of DOC and CDOC export were calculated for 1982–2019 by extrapolating the DOC and CDOC concentration—discharge relationships from 2009 to 2019 as a hindcast modeled estimate. For the six rivers combined, modeled DOC and CDOC exports increased, but CDOC increased faster than total DOC. The Lena and Ob' Rivers showed significant ...