Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado
© 2017. American Geophysical Union. All Rights Reserved. Although important for riverine solute and nutrient fluxes, the connections between biogeochemical processes and subsurface hydrology remain poorly characterized. We investigate these couplings in the East River, CO, a high-elevation shale-dom...
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ftcdlib:qt3h55d9pf 2023-05-15T15:52:35+02:00 Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado Winnick, MJ Carroll, RWH Williams, KH Maxwell, RM Dong, W Maher, K 2507 - 2523 2017-03-01 application/pdf http://www.escholarship.org/uc/item/3h55d9pf english eng eScholarship, University of California qt3h55d9pf http://www.escholarship.org/uc/item/3h55d9pf public Winnick, MJ; Carroll, RWH; Williams, KH; Maxwell, RM; Dong, W; & Maher, K. (2017). Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado. Water Resources Research, 53(3), 2507 - 2523. doi:10.1002/2016WR019724. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/3h55d9pf article 2017 ftcdlib https://doi.org/10.1002/2016WR019724 2018-09-28T22:52:39Z © 2017. American Geophysical Union. All Rights Reserved. Although important for riverine solute and nutrient fluxes, the connections between biogeochemical processes and subsurface hydrology remain poorly characterized. We investigate these couplings in the East River, CO, a high-elevation shale-dominated catchment in the Rocky Mountains, using concentration-discharge (C-Q) relationships for major cations, anions, and organic carbon. Dissolved organic carbon (DOC) displays a positive C-Q relationship with clockwise hysteresis, indicating mobilization and depletion of DOC in the upper soil horizons and emphasizing the importance of shallow flow paths during snowmelt. Cation and anion concentrations demonstrate that carbonate weathering, which dominates solute fluxes, is promoted by both sulfuric acid derived from pyrite oxidation in the shale bedrock and carbonic acid derived from subsurface respiration. Sulfuric acid weathering dominates during base flow conditions when waters infiltrate below the inferred pyrite oxidation front, whereas carbonic acid weathering plays a dominant role during snowmelt as a result of shallow flow paths. Differential C-Q relationships between solutes suggest that infiltrating waters approach calcite saturation before reaching the pyrite oxidation front, after which sulfuric acid reduces carbonate alkalinity. This reduction in alkalinity results in CO2outgassing when waters equilibrate to surface conditions, and reduces the riverine export of carbon and alkalinity by roughly 33% annually. Future changes in snowmelt dynamics that control the balance of carbonic and sulfuric acid weathering may substantially alter carbon cycling in the East River. Ultimately, we demonstrate that differential C-Q relationships between major solutes can provide unique insights into the complex subsurface flow and biogeochemical dynamics that operate at catchment scales. Article in Journal/Newspaper Carbonic acid University of California: eScholarship Water Resources Research 53 3 2507 2523 |
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Open Polar |
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University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
English |
description |
© 2017. American Geophysical Union. All Rights Reserved. Although important for riverine solute and nutrient fluxes, the connections between biogeochemical processes and subsurface hydrology remain poorly characterized. We investigate these couplings in the East River, CO, a high-elevation shale-dominated catchment in the Rocky Mountains, using concentration-discharge (C-Q) relationships for major cations, anions, and organic carbon. Dissolved organic carbon (DOC) displays a positive C-Q relationship with clockwise hysteresis, indicating mobilization and depletion of DOC in the upper soil horizons and emphasizing the importance of shallow flow paths during snowmelt. Cation and anion concentrations demonstrate that carbonate weathering, which dominates solute fluxes, is promoted by both sulfuric acid derived from pyrite oxidation in the shale bedrock and carbonic acid derived from subsurface respiration. Sulfuric acid weathering dominates during base flow conditions when waters infiltrate below the inferred pyrite oxidation front, whereas carbonic acid weathering plays a dominant role during snowmelt as a result of shallow flow paths. Differential C-Q relationships between solutes suggest that infiltrating waters approach calcite saturation before reaching the pyrite oxidation front, after which sulfuric acid reduces carbonate alkalinity. This reduction in alkalinity results in CO2outgassing when waters equilibrate to surface conditions, and reduces the riverine export of carbon and alkalinity by roughly 33% annually. Future changes in snowmelt dynamics that control the balance of carbonic and sulfuric acid weathering may substantially alter carbon cycling in the East River. Ultimately, we demonstrate that differential C-Q relationships between major solutes can provide unique insights into the complex subsurface flow and biogeochemical dynamics that operate at catchment scales. |
format |
Article in Journal/Newspaper |
author |
Winnick, MJ Carroll, RWH Williams, KH Maxwell, RM Dong, W Maher, K |
spellingShingle |
Winnick, MJ Carroll, RWH Williams, KH Maxwell, RM Dong, W Maher, K Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
author_facet |
Winnick, MJ Carroll, RWH Williams, KH Maxwell, RM Dong, W Maher, K |
author_sort |
Winnick, MJ |
title |
Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
title_short |
Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
title_full |
Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
title_fullStr |
Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
title_full_unstemmed |
Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado |
title_sort |
snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, east river, colorado |
publisher |
eScholarship, University of California |
publishDate |
2017 |
url |
http://www.escholarship.org/uc/item/3h55d9pf |
op_coverage |
2507 - 2523 |
genre |
Carbonic acid |
genre_facet |
Carbonic acid |
op_source |
Winnick, MJ; Carroll, RWH; Williams, KH; Maxwell, RM; Dong, W; & Maher, K. (2017). Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado. Water Resources Research, 53(3), 2507 - 2523. doi:10.1002/2016WR019724. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/3h55d9pf |
op_relation |
qt3h55d9pf http://www.escholarship.org/uc/item/3h55d9pf |
op_rights |
public |
op_doi |
https://doi.org/10.1002/2016WR019724 |
container_title |
Water Resources Research |
container_volume |
53 |
container_issue |
3 |
container_start_page |
2507 |
op_container_end_page |
2523 |
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1766387719884242944 |