David W Clow (Former Employee)
Science and Products
Filter Total Items: 67
Critical nitrogen deposition loads in high-elevation lakes of the western US inferred from paleolimnological records
Critical loads of nitrogen (N) from atmospheric deposition were determined for alpine lake ecosystems in the western US using fossil diatom assemblages in lake sediment cores. Changes in diatom species over the last century were indicative of N enrichment in two areas, the eastern Sierra Nevada, starting between 1960 and 1965, and the Greater Yellowstone Ecosystem, starting in 1980. In contrast, n
Authors
J.E. Saros, David W. Clow, T. Blett, A.P. Wolfe
Responses of soil and water chemistry to mountain pine beetle induced tree mortality in Grand County, Colorado, USA
Pine forest in northern Colorado and southern Wyoming, USA, are experiencing the most severe mountain pine beetle epidemic in recorded history, and possible degradation of drinking-water quality is a major concern. The objective of this study was to investigate possible changes in soil and water chemistry in Grand County, Colorado in response to the epidemic, and to identify major controlling infl
Authors
David W. Clow, Charles Rhoades, Jenny S. Briggs, Megan K. Caldwell, William M. Lewis
Potential climate change effects on water tables and pyrite oxidation in headwater catchments in Colorado
A water, energy, and biogeochemical model (WEBMOD) was constructed to simulate hydrology and pyrite oxidation for the period October 1992 through September 1997. The hydrologic model simulates processes in Loch Vale, a 6.6-km² granitic watershed that drains the east side of the Continental Divide. Parameters describing pyrite oxidation were derived sulfate concentrations measured in pore water and
Authors
Richard M. Webb, M. Alisa Mast, Andrew H. Manning, David W. Clow, Donald H. Campbell
Mechanisms for chemostatic behavior in catchments: implications for CO2 consumption by mineral weathering
Concentrations of weathering products in streams often show relatively little variation compared to changes in discharge, both at event and annual scales. In this study, several hypothesized mechanisms for this “chemostatic behavior” were evaluated, and the potential for those mechanisms to influence relations between climate, weathering fluxes, and CO2 consumption via mineral weathering was asses
Authors
David W. Clow, M. Alisa Mast
Changes in the timing of snowmelt and streamflow in Colorado: A response to recent warming
Trends in the timing of snowmelt and associated runoff in Colorado were evaluated for the 1978-2007 water years using the regional Kendall test (RKT) on daily snow-water equivalent (SWE) data from snowpack telemetry (SNOTEL) sites and daily streamflow data from headwater streams. The RKT is a robust, nonparametric test that provides an increased power of trend detection by grouping data from multi
Authors
David W. Clow
Use of regression‐based models to map sensitivity of aquatic resources to atmospheric deposition in Yosemite National Park, USA
An abundance of exposed bedrock, sparse soil and vegetation, and fast hydrologic flushing rates make aquatic ecosystems in Yosemite National Park susceptible to nutrient enrichment and episodic acidification due to atmospheric deposition of nitrogen (N) and sulfur (S). In this study, multiple linear regression (MLR) models were created to estimate fall‐season nitrate and acid neutralizing capacity
Authors
David W. Clow, Leora Nanus, Brian Huggett
DayCent-Chem simulations of ecological and biogeochemical processes of eight mountain ecosystems in the United States
Atmospheric deposition of nitrogen (N) and sulfur (S) cause complex responses in ecosystems, from fertilization to forest ecosystem decline, freshwater eutrophication to acidification, loss of soil base cations, and alterations of disturbance regimes. DayCent-Chem, an ecosystem simulation model that combines ecosystem nutrient cycling and plant dynamics with aqueous geochemical equilibrium calcula
Authors
Melannie D. Hartman, Jill S. Baron, David W. Clow, Irena F. Creed, Charles T. Driscoll, Holly A. Ewing, Bruce D. Haines, Jennifer Knoepp, Kate Lajtha, Dennis S. Ojima, William J. Parton, Jim Renfro, R. Bruce Robinson, Helga Van Miegroet, Kathleen C. Weathers, Mark W. Williams
Rocky Mountain Snowpack Physical and Chemical Data for Selected Sites, 1993-2008
The Rocky Mountain Snowpack program established a network of snowpack-sampling sites in the Rocky Mountain region from New Mexico to Montana to monitor the chemical content of snow to help in the understanding of the effects of atmospheric deposition to this region. The U.S. Geological Survey, in cooperation with the National Park Service, the USDA Forest Service, Teton County in Wyoming, Rio Blan
Authors
George P. Ingersoll, M. Alisa Mast, Donald H. Campbell, David W. Clow, Leora Nanus, John T. Turk
Selected achievements, science directions, and new opportunities for the WEBB small watershed research program
Over nearly two decades, the Water, Energy, and Biogeochemical Budgets (WEBB) small watershed research program of the U.S. Geological Survey (USGS) has documented how water and solute fluxes, nutrient, carbon, and mercury dynamics, and weathering and sediment transport respond to natural and humancaused drivers, including climate, climate change, and atmospheric deposition. Together with a continu
Authors
Pierre D. Glynn, Matthew C. Larsen, Earl A. Greene, Heather L. Buss, David W. Clow, Randall J. Hunt, M. Alisa Mast, Sheila F. Murphy, Norman E. Peters, Stephen D. Sebestyen, James B. Shanley, John F. Walker
Atmospheric Deposition and Surface-Water Chemistry in Mount Rainier and North Cascades National Parks, U.S.A., Water Years 2000 and 2005-2006
High-elevation aquatic ecosystems in Mount Rainier and North Cascades National Parks are highly sensitive to atmospheric deposition of nitrogen and sulfur. Thin, rocky soils promote fast hydrologic flushing rates during snowmelt and rain events, limiting the ability of basins to neutralize acidity and assimilate nitrogen deposited from the atmosphere. Potential effects of nitrogen and sulfur depos
Authors
David W. Clow, Donald H. Campbell
Tracer gauge: An automated dye dilution gauging system for ice‐affected streams
In‐stream flow protection programs require accurate, real‐time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in‐channel ice causes variable backwater conditions and alters the stage‐discharge relation. In this study, an automated dye dilution gauging system, a tracer ga
Authors
David W. Clow, Andrea C. Fleming
Effects of 2003 wildfires on stream chemistry in Glacier National Park, Montana
Changes in stream chemistry were studied for 4 years following large wildfires that burned in Glacier National Park during the summer of 2003. Burned and unburned drainages were monitored from December 2003 through August 2007 for streamflow, major constituents, nutrients, and suspended sediment following the fires. Stream-water nitrate concentrations showed the greatest response to fire, increasi
Authors
M. Alisa Mast, David W. Clow
Science and Products
Filter Total Items: 67
Critical nitrogen deposition loads in high-elevation lakes of the western US inferred from paleolimnological records
Critical loads of nitrogen (N) from atmospheric deposition were determined for alpine lake ecosystems in the western US using fossil diatom assemblages in lake sediment cores. Changes in diatom species over the last century were indicative of N enrichment in two areas, the eastern Sierra Nevada, starting between 1960 and 1965, and the Greater Yellowstone Ecosystem, starting in 1980. In contrast, n
Authors
J.E. Saros, David W. Clow, T. Blett, A.P. Wolfe
Responses of soil and water chemistry to mountain pine beetle induced tree mortality in Grand County, Colorado, USA
Pine forest in northern Colorado and southern Wyoming, USA, are experiencing the most severe mountain pine beetle epidemic in recorded history, and possible degradation of drinking-water quality is a major concern. The objective of this study was to investigate possible changes in soil and water chemistry in Grand County, Colorado in response to the epidemic, and to identify major controlling infl
Authors
David W. Clow, Charles Rhoades, Jenny S. Briggs, Megan K. Caldwell, William M. Lewis
Potential climate change effects on water tables and pyrite oxidation in headwater catchments in Colorado
A water, energy, and biogeochemical model (WEBMOD) was constructed to simulate hydrology and pyrite oxidation for the period October 1992 through September 1997. The hydrologic model simulates processes in Loch Vale, a 6.6-km² granitic watershed that drains the east side of the Continental Divide. Parameters describing pyrite oxidation were derived sulfate concentrations measured in pore water and
Authors
Richard M. Webb, M. Alisa Mast, Andrew H. Manning, David W. Clow, Donald H. Campbell
Mechanisms for chemostatic behavior in catchments: implications for CO2 consumption by mineral weathering
Concentrations of weathering products in streams often show relatively little variation compared to changes in discharge, both at event and annual scales. In this study, several hypothesized mechanisms for this “chemostatic behavior” were evaluated, and the potential for those mechanisms to influence relations between climate, weathering fluxes, and CO2 consumption via mineral weathering was asses
Authors
David W. Clow, M. Alisa Mast
Changes in the timing of snowmelt and streamflow in Colorado: A response to recent warming
Trends in the timing of snowmelt and associated runoff in Colorado were evaluated for the 1978-2007 water years using the regional Kendall test (RKT) on daily snow-water equivalent (SWE) data from snowpack telemetry (SNOTEL) sites and daily streamflow data from headwater streams. The RKT is a robust, nonparametric test that provides an increased power of trend detection by grouping data from multi
Authors
David W. Clow
Use of regression‐based models to map sensitivity of aquatic resources to atmospheric deposition in Yosemite National Park, USA
An abundance of exposed bedrock, sparse soil and vegetation, and fast hydrologic flushing rates make aquatic ecosystems in Yosemite National Park susceptible to nutrient enrichment and episodic acidification due to atmospheric deposition of nitrogen (N) and sulfur (S). In this study, multiple linear regression (MLR) models were created to estimate fall‐season nitrate and acid neutralizing capacity
Authors
David W. Clow, Leora Nanus, Brian Huggett
DayCent-Chem simulations of ecological and biogeochemical processes of eight mountain ecosystems in the United States
Atmospheric deposition of nitrogen (N) and sulfur (S) cause complex responses in ecosystems, from fertilization to forest ecosystem decline, freshwater eutrophication to acidification, loss of soil base cations, and alterations of disturbance regimes. DayCent-Chem, an ecosystem simulation model that combines ecosystem nutrient cycling and plant dynamics with aqueous geochemical equilibrium calcula
Authors
Melannie D. Hartman, Jill S. Baron, David W. Clow, Irena F. Creed, Charles T. Driscoll, Holly A. Ewing, Bruce D. Haines, Jennifer Knoepp, Kate Lajtha, Dennis S. Ojima, William J. Parton, Jim Renfro, R. Bruce Robinson, Helga Van Miegroet, Kathleen C. Weathers, Mark W. Williams
Rocky Mountain Snowpack Physical and Chemical Data for Selected Sites, 1993-2008
The Rocky Mountain Snowpack program established a network of snowpack-sampling sites in the Rocky Mountain region from New Mexico to Montana to monitor the chemical content of snow to help in the understanding of the effects of atmospheric deposition to this region. The U.S. Geological Survey, in cooperation with the National Park Service, the USDA Forest Service, Teton County in Wyoming, Rio Blan
Authors
George P. Ingersoll, M. Alisa Mast, Donald H. Campbell, David W. Clow, Leora Nanus, John T. Turk
Selected achievements, science directions, and new opportunities for the WEBB small watershed research program
Over nearly two decades, the Water, Energy, and Biogeochemical Budgets (WEBB) small watershed research program of the U.S. Geological Survey (USGS) has documented how water and solute fluxes, nutrient, carbon, and mercury dynamics, and weathering and sediment transport respond to natural and humancaused drivers, including climate, climate change, and atmospheric deposition. Together with a continu
Authors
Pierre D. Glynn, Matthew C. Larsen, Earl A. Greene, Heather L. Buss, David W. Clow, Randall J. Hunt, M. Alisa Mast, Sheila F. Murphy, Norman E. Peters, Stephen D. Sebestyen, James B. Shanley, John F. Walker
Atmospheric Deposition and Surface-Water Chemistry in Mount Rainier and North Cascades National Parks, U.S.A., Water Years 2000 and 2005-2006
High-elevation aquatic ecosystems in Mount Rainier and North Cascades National Parks are highly sensitive to atmospheric deposition of nitrogen and sulfur. Thin, rocky soils promote fast hydrologic flushing rates during snowmelt and rain events, limiting the ability of basins to neutralize acidity and assimilate nitrogen deposited from the atmosphere. Potential effects of nitrogen and sulfur depos
Authors
David W. Clow, Donald H. Campbell
Tracer gauge: An automated dye dilution gauging system for ice‐affected streams
In‐stream flow protection programs require accurate, real‐time streamflow data to aid in the protection of aquatic ecosystems during winter base flow periods. In cold regions, however, winter streamflow often can only be estimated because in‐channel ice causes variable backwater conditions and alters the stage‐discharge relation. In this study, an automated dye dilution gauging system, a tracer ga
Authors
David W. Clow, Andrea C. Fleming
Effects of 2003 wildfires on stream chemistry in Glacier National Park, Montana
Changes in stream chemistry were studied for 4 years following large wildfires that burned in Glacier National Park during the summer of 2003. Burned and unburned drainages were monitored from December 2003 through August 2007 for streamflow, major constituents, nutrients, and suspended sediment following the fires. Stream-water nitrate concentrations showed the greatest response to fire, increasi
Authors
M. Alisa Mast, David W. Clow