The chemostatic, diluting, and flushing behavior of DOC and other analytes in the six largest Arctic rivers
Abstract
Despite the impact of solute exports on the biogeochemistry of the Arctic Ocean and surrounding ecosystems, the long term relationships between concentration and discharge in the largest six Arctic river systems have been sparsely studied. This study utilized a relatively novel chemostatic analysis approach to understand the variance in solute concentrations with discharge. Using data from ArcticGRO (https://arcticgreatrivers.org/data/), this approach characterizes solutes as flushing, dilutive, or chemostatic depending on whether concentrations increase, decrease, or remain the same with respect to discharge over long timescales. Studying concentration discharge relationships in this way gives a high level of understanding of how exports are changing with respect to discharge in the six largest Arctic rivers (Kolyma, Lena, Mackenzie, Ob, Yenisey, and Yukon). Using the ArcticGRO database, this study analyzed the chemostatic, flushing, and dilutive behavior of 20 different analytes (including dissolved organic carbon (DOC), nitrate, and phosphate) with data collected between 2003 and 2017. Initial results indicated that DOC behaved chemostatically in the Kolyma, Lena, Ob, and Mackenzie rivers from 2003 through 2017, but exhibited flushing behavior in the Yukon and Yenisey rivers. By contrast, nitrate exhibited dilutive behavior in all six rivers. In contrast to both of these, phosphate exhibited variably chemostatic, flushing, or dilutive behavior, depending on the river system. This work provides a baseline of seasonal and annual concentration-discharge behavior that can be used to explore the biogeochemistry of large Arctic watersheds and their impact on current solute fluxes to the Arctic Ocean. This baseline analysis can be used as a comparison dataset to understand how changing climate drives future changes in Arctic hydrology and solute fluxes.
'LA-UR-20-25641'- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB120...12N
- Keywords:
-
- 0428 Carbon cycling;
- BIOGEOSCIENCES;
- 0470 Nutrients and nutrient cycling;
- BIOGEOSCIENCES;
- 0475 Permafrost;
- cryosphere;
- and high-latitude processes;
- BIOGEOSCIENCES;
- 1823 Frozen ground;
- HYDROLOGY