Mountains, erosion and the carbon cycle

Nature Reviews Earth & Environment, Journal Year: 2020, Volume and Issue: 1(6), P. 284 - 299

Published: June 9, 2020

Language: Английский

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A low-to-no snow future and its impacts on water resources in the western United States

Nature Reviews Earth & Environment, Journal Year: 2021, Volume and Issue: 2(11), P. 800 - 819

Published: Oct. 26, 2021

Language: Английский

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The East River, Colorado, Watershed: A Mountainous Community Testbed for Improving Predictive Understanding of Multiscale Hydrological–Biogeochemical Dynamics

Vadose Zone Journal, Journal Year: 2018, Volume and Issue: 17(1), P. 1 - 25

Published: Jan. 1, 2018

Core Ideas Development of a 300‐km 2 mountainous headwater testbed began in 2016 the East River. The can be used to explore how watershed changes impact downgradient water availability and quality. System‐of‐system, scale‐adaptive approaches potentially improve dynamics simulation. We have new monitor simulate partitioning system responses. River has been developed as “community” testbed. Extreme weather, fires, land use climate change are significantly reshaping interactions within watersheds throughout world. Although hydrological–biogeochemical many services valued by society, uncertainty associated with predicting hydrology‐driven biogeochemical remains high. With an aim reduce this uncertainty, approximately observatory at River, CO, Upper Colorado Basin. site is being for Department Energy supported Watershed Function Project collaborative efforts. Building on insights gained from research “sister” Rifle, site, coordinated studies underway gain predictive understanding retains releases water, nutrients, carbon, metals. In particular, project exploring early snowmelt, drought, other disturbances influence seasonal decadal timescales. A system‐of‐systems perspective simulation approach, involving combined archetypal subsystem “intensive sites” tested inform aggregated predictions exports. Complementing intensive hydrological, geochemical, geophysical, microbiological, geological, vegetation datasets long‐term, distributed measurement stations specialized experimental observational campaigns. Several recent advances provide about sites well behavior. “community testbed” currently hosting scientists more than 30 institutions advance methods understanding.

Language: Английский

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Distinct Source Water Chemistry Shapes Contrasting Concentration‐Discharge Patterns

Water Resources Research, Journal Year: 2019, Volume and Issue: 55(5), P. 4233 - 4251

Published: April 15, 2019

Abstract Understanding concentration‐discharge (C‐Q) relationships are essential for predicting chemical weathering and biogeochemical cycling under changing climate anthropogenic conditions. Contrasting C‐Q have been observed widely, yet a mechanistic framework that can interpret diverse patterns remains elusive. This work hypothesizes seemingly disparate driven by switching dominance of end‐member source waters their contrasts arising from subsurface heterogeneity. We use data Coal Creek, high‐elevation mountainous catchment in Colorado, recently developed watershed reactive transport model (BioRT‐Flux‐PIHM). Sensitivity analysis Monte‐Carlo simulations (500 cases) show reaction kinetics thermodynamics distribution materials across depths govern the chemistry gradients shallow soil water deeper groundwater entering stream. The alternating organic‐poor geo‐solute‐rich dry conditions organic‐rich geo‐solute‐poor during spring melt leads to flushing pattern dissolved organic carbon dilution geogenic solutes (e.g., Na, Ca, Mg). In addition, extent concentration regulates power law slopes ( b ) via general equation . At low ratios versus concentrations (C ratio = C sw /C gw < 0.6), occurs; at high > 1.8), arises; chemostasis occurs between. quantitatively interprets values 11 (dissolved carbon, P, NO 3 − , K, Si, Mg, Al, Mn, Fe) three catchments (Coal Shale Hills, Plynlimon) differing climate, geologic, land cover indicates potentially broad regulation heterogeneity determining wide applications this quantifying values, which implications transformation scale.

Language: Английский

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Factors controlling seasonal groundwater and solute flux from snow‐dominated basins

Hydrological Processes, Journal Year: 2018, Volume and Issue: 32(14), P. 2187 - 2202

Published: May 15, 2018

Abstract Critical zone influences on hydrologic partitioning, subsurface flow paths and reactions along these dictate the timing magnitude of groundwater solute flux to streams. To isolate first‐order controls seasonal streamflow generation within highly heterogeneous, snow‐dominated basins Colorado River, we employ a multivariate statistical approach end‐member mixing analysis using suite daily chemical isotopic observations. Mixing models are developed across 11 nested (0.4 85 km 2 ) spanning gradient climatological, physical, geological characteristics. Hydrograph separation rain, snow, as end‐members indicates that contributions streams is significant. Mean annual ranges from 12% 33% whereas maximum 17% 50% occur during baseflow. The direct relationship between snow water equivalent scale dependent with trend toward self‐similarity when exceed 5.5 . We find recharge increases in high relief upper subalpine where accumulation coincident reduced conifer cover lower canopy densities. model for furthest downstream site did not transfer upstream basins. resulting error predicted stream concentrations points weathering function source rock shifts path. Additionally, potential microbial sulfate reduction floodplain sediments low‐gradient, meandering portion river sufficient modify hillslope alter ratios analysis. Soil flushing response snowmelt included an but identified important mechanism release solutes mountainous watersheds. End‐member used combination high‐frequency observations reveals aspects catchment hydrodynamics scale.

Language: Английский

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Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

Earth and Planetary Science Letters, Journal Year: 2018, Volume and Issue: 485, P. 111 - 120

Published: Jan. 27, 2018

Language: Английский

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Embracing the dynamic nature of soil structure: A paradigm illuminating the role of life in critical zones of the Anthropocene

Earth-Science Reviews, Journal Year: 2021, Volume and Issue: 225, P. 103873 - 103873

Published: Nov. 26, 2021

Language: Английский

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Temperature control on CO2 emissions from the weathering of sedimentary rocks

Nature Geoscience, Journal Year: 2021, Volume and Issue: 14(9), P. 665 - 671

Published: Aug. 30, 2021

Language: Английский

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A graph neural network (GNN) approach to basin-scale river network learning: the role of physics-based connectivity and data fusion

Hydrology and earth system sciences, Journal Year: 2022, Volume and Issue: 26(19), P. 5163 - 5184

Published: Oct. 14, 2022

Abstract. Rivers and river habitats around the world are under sustained pressure from human activities changing global environment. Our ability to quantify manage states in a timely manner is critical for protecting public safety natural resources. In recent years, vector-based network models have enabled modeling of large basins at increasingly fine resolutions, but computationally demanding. This work presents multistage, physics-guided, graph neural (GNN) approach basin-scale learning streamflow forecasting. During training, we train GNN model approximate outputs high-resolution model; then fine-tune pretrained with observations. We further apply graph-based, data-fusion step correct prediction biases. The GNN-based framework first demonstrated over snow-dominated watershed western United States. A series experiments performed test different training imputation strategies. Results show that trained can effectively serve as surrogate process-based high accuracy, median Kling–Gupta efficiency (KGE) greater than 0.97. Application graph-based data fusion reduces mismatch between observations, much 50 % KGE improvement some cross-validation gages. To improve scalability, graph-coarsening procedure introduced larger basin. coarsening achieves comparable skills only fraction cost, thus providing important insights into degree physical realism needed developing large-scale models.

Language: Английский

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Impacts of Carbonate Buffering on Atmospheric Equilibration of CO₂, δ¹³C_DIC, and Δ¹⁴C_DIC in Rivers and Streams

Global Biogeochemical Cycles, Journal Year: 2024, Volume and Issue: 38(2)

Published: Feb. 1, 2024

Abstract Rivers and streams play an important role within the global carbon cycle, in part through emissions of dioxide (CO 2 ) to atmosphere. However, sources this CO their spatiotemporal variability are difficult constrain. Recent work has highlighted carbonate buffering reactions that may serve as a source high alkalinity systems. In study, we seek develop quantitative framework for fluxes patterns stable radio‐ isotope composition dissolved inorganic (DIC). We incorporate DIC speciation calculations isotopologues into stream network model perform series simulations, ranging from degassing groundwater seep hydrologically‐coupled 5th‐order network. find contribute >60% high‐alkalinity, moderate groundwater‐CO environments. atmosphere equilibration timescales minimally affected, which contradicts hypotheses maintains across Strahler orders contrast, dramatically increases timescales, acts decouple variations isotopic even under low alkalinity. This significantly complicates common method identification. Based on similar impacts atmospheric isotopologues, partitioning corridor carbonate‐dominated watersheds. Together, these results provide guide fieldwork interpretations variable alkalinities.

Language: Английский

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