David W Clow (Former Employee)
Science and Products
Linking water, carbon, and nitrogen cycles in seasonally snow-covered catchments under changing land resource conditions
Changes in snowpack accumulation, distribution, and melt in high-elevation catchments are likely to have important impacts on water, carbon, and nitrogen cycles, which are tightly coupled through exchanges of energy and biogeochemical compounds between atmospheric, terrestrial, and aquatic environments. Our research helps to better understand how changes in climate will affect water availability...
Developing Tools for Improved Water Supply Forecasting in the Rio Grande Headwaters
The Rio Grande River is a critical source of freshwater for 13 million people in Colorado, Texas, New Mexico, and Mexico. More than half of the Rio Grande’s streamflow originates as snowmelt in Colorado’s mountains, meaning that changes in the amount of snowmelt can impact the water supply for communities along the entire river. Snowmelt runoff is therefore an important component of...
Transport of dissolved organic matter by river networks from mountains to the sea: a re-examination of the role of flow across temporal and spatial scales
The transport of dissolved organic matter (DOM) by rivers is an important component of the global carbon cycle, affects ecosystems and water quality, and reflects biogeochemical and hydrological processes in watersheds. Understanding the fundamental relationships between discharge and DOM concentration and composition reveals important information about watershed flow paths, soil...
Snowpack Sublimation - Measurements and Modeling in the Colorado River Basin
Snow is an essential resource in the western United States (U.S.), providing water for drinking, irrigation, industry, energy production, and ecosystems across much of the region. In the mountains of the western U.S., most precipitation falls as snow, which accumulates in seasonal snowpacks that serve as a large natural reservoir. Snowpack sublimation, which is analogous to evaporation from land...
Water, Energy, and Biogeochemical Budgets (WEBB): Loch Vale Watershed
Loch Vale is an alpine/subalpine watershed in Rocky Mountain National Park where the U.S. Geological Survey has been conducting research since the 1980s. Our research has focused on the effects of climate change and atmospheric pollutants on water, soil, vegetation, and aquatic life. The alpine/subalpine ecosystem in Loch Vale is sensitive to changes in climate and air pollution. Our long-term...
Water-Quality Sampling at Five Hydrologic Benchmark Stations in the Western United States
The Hydrologic Benchmark Network (HBN) was established in 1963 to provide long-term measurements of streamflow and water quality in areas of the United States that are minimally affected by human activities.
Estimates of water-quality concentrations from two watersheds affected by the 2020 Cameron Peak Fire in Larimer County, Colorado Estimates of water-quality concentrations from two watersheds affected by the 2020 Cameron Peak Fire in Larimer County, Colorado
This data repository documents the input files, output files, and RStudio scripts used to quantify changes in water-quality concentrations after the 2020 Cameron Peak Fire in the North Fork Big Thompson River and Buckhorn Creek watersheds using the Weighted Regressions on Time, Discharge, and Season (WRTDS) method. A WRTDS model was developed using 12 years of pre-fire data (2008-August...
In-stream and laboratory fDOM data from wildfire affected streams of the western United States, 2021-22 In-stream and laboratory fDOM data from wildfire affected streams of the western United States, 2021-22
After wildfires occurred in the western United States during 2020, in-stream water quality monitors and automatic samplers were deployed in four burned watersheds and one unburned watershed. In-stream water temperature, turbidity, and fluorescent dissolved organic matter (fDOM) were measured at high frequency, and the fDOM data were corrected for temperature and turbidity effects...
Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011 - 19 (ver. 3.0, October 2023) Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011 - 19 (ver. 3.0, October 2023)
This data release contains water-quality and discharge data collected at seven stream sites and one groundwater spring in Rocky Mountain National Park (RMNP), Colorado by the U.S. Geological Survey (USGS) from 10/1/2010 to 9/30/2019 using in-situ sensors and field meters. Data were collected for the purpose of quantifying downstream transport of aquatic carbon and exchange fluxes of...
Stable hydrogen and oxygen isotopic compositions of precipitation samples from selected Colorado and Utah National Atmospheric Deposition Program (NADP) sites Stable hydrogen and oxygen isotopic compositions of precipitation samples from selected Colorado and Utah National Atmospheric Deposition Program (NADP) sites
The stable hydrogen (delta 2H) and oxygen (delta 18O) isotopic compositions of more than 4,300 weekly composite samples of precipitation from thirteen National Atmospheric Deposition Program (NADP) sites (CO02, CO08, CO09, CO10, CO21, CO89, CO91, CO92, CO93, CO96, CO97, CO98, and UT09) in Colorado and Utah were analyzed on archived samples obtained from NADP over various time periods...
Seasonal Atmospheric Nitrate and Ammonium Deposition along an Elevation Gradient in the Colorado Front Range using Ion Exchange Resin Columns (2018-2019) Seasonal Atmospheric Nitrate and Ammonium Deposition along an Elevation Gradient in the Colorado Front Range using Ion Exchange Resin Columns (2018-2019)
Atmospheric deposition of reactive nitrogen (Nr) due to human activities can have measurable effects on ecosystem processing and export of nutrients, groundwater and surface-water quality. Rates of Nr deposition to lower-elevation forests immediately adjacent to the Denver/Boulder urban area, however, have only recently been measured. The focus of this study was to determine the extent...
Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011-19 (ver. 2.0, January 2022) Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011-19 (ver. 2.0, January 2022)
This data release contains water-quality and discharge data collected at seven stream sites and one groundwater spring in Rocky Mountain National Park (RMNP), Colorado by the U.S. Geological Survey (USGS) from 10/1/2010 to 9/30/2019 using in-situ sensors and field meters. Data were collected for the purpose of quantifying downstream transport of aquatic carbon and exchange fluxes of...
Filter Total Items: 72
Characterizing water-quality response after the 2020 Cameron Peak Fire using a novel application of the Weighted Regressions on Time, Discharge, and Season method Characterizing water-quality response after the 2020 Cameron Peak Fire using a novel application of the Weighted Regressions on Time, Discharge, and Season method
The frequency and severity of wildfire activity in the western United States emphasises the utility of hydrologic models to predict water-quality response. This study presents a novel application of the Weighted Regressions on Time, Discharge and Season (WRTDS) method to assess potential changes in water quality in two watersheds draining the North Fork Big Thompson River and Buckhorn...
Authors
Manya Helene Ruckhaus, David W. Clow, Robert M. Hirsch, Tanner William Chapin
Hysteretic response of suspended-sediment in wildfire affected watersheds of the Pacific Northwest and Southern Rocky Mountains Hysteretic response of suspended-sediment in wildfire affected watersheds of the Pacific Northwest and Southern Rocky Mountains
Wildfires can have a profound impact on hydrosedimentary interactions, or the relationship between sediment and runoff, in forested headwater streams. Quantification of sediment-runoff dynamics at the event scale is integral for understanding source areas and transport of suspended-sediment through a watershed following wildfire. Here we used high-frequency turbidity and stream discharge...
Authors
Gregory D. Clark, Sheila F. Murphy, Katherine Skalak, David W. Clow, Garrett Alexander Akie, Kurt D. Carpenter, Sean E. Payne, Brian A. Ebel
An intercomparison of DOC estimated from fDOM sensors in wildfire affected streams of the western United States An intercomparison of DOC estimated from fDOM sensors in wildfire affected streams of the western United States
Wildfires in the western United States (US) have been demonstrated to affect water quality, including dissolved organic carbon (DOC), in streams. Elevated post-wildfire DOC concentration poses a potential risk to drinking water treatment systems. In-stream measurements of fluorescent dissolved organic matter (fDOM), a proxy for DOC, have shown potential to detect dynamic changes in DOC...
Authors
Garrett Alexander Akie, David W. Clow, Sheila F. Murphy, Gregory D. Clark, Michael R. Meador, Brian A. Ebel
Dynamic water-quality responses to wildfire in Colorado Dynamic water-quality responses to wildfire in Colorado
In 2020, Colorado experienced the most severe wildfire season in recorded history, with wildfires burning 625 357 acres across the state. Two of the largest fires burned parts of Rocky Mountain National Park (RMNP), and a study was initiated to address concerns about potential effects on drinking water quality from mobilization of ash and sediment. The study took advantage of a wealth of...
Authors
David W. Clow, Garrett Alexander Akie, Sheila F. Murphy, Evan J. Gohring
Aquatic carbon export and dynamics in mountain headwater streams of the western U.S. Aquatic carbon export and dynamics in mountain headwater streams of the western U.S.
Mountain headwater streams actively cycle carbon, receiving it from terrestrial landscapes and exporting it through downstream transport and gas exchange with the atmosphere. Although their importance is now widely recognized, aquatic carbon fluxes in headwater streams remain poorly characterized. In this study, aquatic carbon fluxes were measured in 15 mountain headwater streams and...
Authors
David W. Clow, Garrett Alexander Akie, Robert G. Striegl, Colin Penn, Graham A. Sexstone, Gabrielle L. Keith
A call for strategic water-quality monitoring to advance assessment and prediction of wildfire impacts on water supplies A call for strategic water-quality monitoring to advance assessment and prediction of wildfire impacts on water supplies
Wildfires pose a risk to water supplies in the western U.S. and many other parts of the world, due to the potential for degradation of water quality. However, a lack of adequate data hinders prediction and assessment of post-wildfire impacts and recovery. The dearth of such data is related to lack of funding for monitoring extreme events and the challenge of measuring the outsized...
Authors
Sheila F. Murphy, Charles N. Alpers, Chauncey W. Anderson, John R. Banta, Johanna Blake, Kurt D. Carpenter, Gregory D. Clark, David W. Clow, Laura A. Hempel, Deborah A. Martin, Michael R. Meador, Gregory Mendez, Anke Mueller-Solger, Marc A. Stewart, Sean E. Payne, Cara L. Peterman-Phipps, Brian A. Ebel
Science and Products
Linking water, carbon, and nitrogen cycles in seasonally snow-covered catchments under changing land resource conditions
Changes in snowpack accumulation, distribution, and melt in high-elevation catchments are likely to have important impacts on water, carbon, and nitrogen cycles, which are tightly coupled through exchanges of energy and biogeochemical compounds between atmospheric, terrestrial, and aquatic environments. Our research helps to better understand how changes in climate will affect water availability...
Developing Tools for Improved Water Supply Forecasting in the Rio Grande Headwaters
The Rio Grande River is a critical source of freshwater for 13 million people in Colorado, Texas, New Mexico, and Mexico. More than half of the Rio Grande’s streamflow originates as snowmelt in Colorado’s mountains, meaning that changes in the amount of snowmelt can impact the water supply for communities along the entire river. Snowmelt runoff is therefore an important component of...
Transport of dissolved organic matter by river networks from mountains to the sea: a re-examination of the role of flow across temporal and spatial scales
The transport of dissolved organic matter (DOM) by rivers is an important component of the global carbon cycle, affects ecosystems and water quality, and reflects biogeochemical and hydrological processes in watersheds. Understanding the fundamental relationships between discharge and DOM concentration and composition reveals important information about watershed flow paths, soil...
Snowpack Sublimation - Measurements and Modeling in the Colorado River Basin
Snow is an essential resource in the western United States (U.S.), providing water for drinking, irrigation, industry, energy production, and ecosystems across much of the region. In the mountains of the western U.S., most precipitation falls as snow, which accumulates in seasonal snowpacks that serve as a large natural reservoir. Snowpack sublimation, which is analogous to evaporation from land...
Water, Energy, and Biogeochemical Budgets (WEBB): Loch Vale Watershed
Loch Vale is an alpine/subalpine watershed in Rocky Mountain National Park where the U.S. Geological Survey has been conducting research since the 1980s. Our research has focused on the effects of climate change and atmospheric pollutants on water, soil, vegetation, and aquatic life. The alpine/subalpine ecosystem in Loch Vale is sensitive to changes in climate and air pollution. Our long-term...
Water-Quality Sampling at Five Hydrologic Benchmark Stations in the Western United States
The Hydrologic Benchmark Network (HBN) was established in 1963 to provide long-term measurements of streamflow and water quality in areas of the United States that are minimally affected by human activities.
Estimates of water-quality concentrations from two watersheds affected by the 2020 Cameron Peak Fire in Larimer County, Colorado Estimates of water-quality concentrations from two watersheds affected by the 2020 Cameron Peak Fire in Larimer County, Colorado
This data repository documents the input files, output files, and RStudio scripts used to quantify changes in water-quality concentrations after the 2020 Cameron Peak Fire in the North Fork Big Thompson River and Buckhorn Creek watersheds using the Weighted Regressions on Time, Discharge, and Season (WRTDS) method. A WRTDS model was developed using 12 years of pre-fire data (2008-August...
In-stream and laboratory fDOM data from wildfire affected streams of the western United States, 2021-22 In-stream and laboratory fDOM data from wildfire affected streams of the western United States, 2021-22
After wildfires occurred in the western United States during 2020, in-stream water quality monitors and automatic samplers were deployed in four burned watersheds and one unburned watershed. In-stream water temperature, turbidity, and fluorescent dissolved organic matter (fDOM) were measured at high frequency, and the fDOM data were corrected for temperature and turbidity effects...
Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011 - 19 (ver. 3.0, October 2023) Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011 - 19 (ver. 3.0, October 2023)
This data release contains water-quality and discharge data collected at seven stream sites and one groundwater spring in Rocky Mountain National Park (RMNP), Colorado by the U.S. Geological Survey (USGS) from 10/1/2010 to 9/30/2019 using in-situ sensors and field meters. Data were collected for the purpose of quantifying downstream transport of aquatic carbon and exchange fluxes of...
Stable hydrogen and oxygen isotopic compositions of precipitation samples from selected Colorado and Utah National Atmospheric Deposition Program (NADP) sites Stable hydrogen and oxygen isotopic compositions of precipitation samples from selected Colorado and Utah National Atmospheric Deposition Program (NADP) sites
The stable hydrogen (delta 2H) and oxygen (delta 18O) isotopic compositions of more than 4,300 weekly composite samples of precipitation from thirteen National Atmospheric Deposition Program (NADP) sites (CO02, CO08, CO09, CO10, CO21, CO89, CO91, CO92, CO93, CO96, CO97, CO98, and UT09) in Colorado and Utah were analyzed on archived samples obtained from NADP over various time periods...
Seasonal Atmospheric Nitrate and Ammonium Deposition along an Elevation Gradient in the Colorado Front Range using Ion Exchange Resin Columns (2018-2019) Seasonal Atmospheric Nitrate and Ammonium Deposition along an Elevation Gradient in the Colorado Front Range using Ion Exchange Resin Columns (2018-2019)
Atmospheric deposition of reactive nitrogen (Nr) due to human activities can have measurable effects on ecosystem processing and export of nutrients, groundwater and surface-water quality. Rates of Nr deposition to lower-elevation forests immediately adjacent to the Denver/Boulder urban area, however, have only recently been measured. The focus of this study was to determine the extent...
Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011-19 (ver. 2.0, January 2022) Continuous water-quality data for selected streams in Rocky Mountain National Park, Colorado, water years 2011-19 (ver. 2.0, January 2022)
This data release contains water-quality and discharge data collected at seven stream sites and one groundwater spring in Rocky Mountain National Park (RMNP), Colorado by the U.S. Geological Survey (USGS) from 10/1/2010 to 9/30/2019 using in-situ sensors and field meters. Data were collected for the purpose of quantifying downstream transport of aquatic carbon and exchange fluxes of...
Filter Total Items: 72
Characterizing water-quality response after the 2020 Cameron Peak Fire using a novel application of the Weighted Regressions on Time, Discharge, and Season method Characterizing water-quality response after the 2020 Cameron Peak Fire using a novel application of the Weighted Regressions on Time, Discharge, and Season method
The frequency and severity of wildfire activity in the western United States emphasises the utility of hydrologic models to predict water-quality response. This study presents a novel application of the Weighted Regressions on Time, Discharge and Season (WRTDS) method to assess potential changes in water quality in two watersheds draining the North Fork Big Thompson River and Buckhorn...
Authors
Manya Helene Ruckhaus, David W. Clow, Robert M. Hirsch, Tanner William Chapin
Hysteretic response of suspended-sediment in wildfire affected watersheds of the Pacific Northwest and Southern Rocky Mountains Hysteretic response of suspended-sediment in wildfire affected watersheds of the Pacific Northwest and Southern Rocky Mountains
Wildfires can have a profound impact on hydrosedimentary interactions, or the relationship between sediment and runoff, in forested headwater streams. Quantification of sediment-runoff dynamics at the event scale is integral for understanding source areas and transport of suspended-sediment through a watershed following wildfire. Here we used high-frequency turbidity and stream discharge...
Authors
Gregory D. Clark, Sheila F. Murphy, Katherine Skalak, David W. Clow, Garrett Alexander Akie, Kurt D. Carpenter, Sean E. Payne, Brian A. Ebel
An intercomparison of DOC estimated from fDOM sensors in wildfire affected streams of the western United States An intercomparison of DOC estimated from fDOM sensors in wildfire affected streams of the western United States
Wildfires in the western United States (US) have been demonstrated to affect water quality, including dissolved organic carbon (DOC), in streams. Elevated post-wildfire DOC concentration poses a potential risk to drinking water treatment systems. In-stream measurements of fluorescent dissolved organic matter (fDOM), a proxy for DOC, have shown potential to detect dynamic changes in DOC...
Authors
Garrett Alexander Akie, David W. Clow, Sheila F. Murphy, Gregory D. Clark, Michael R. Meador, Brian A. Ebel
Dynamic water-quality responses to wildfire in Colorado Dynamic water-quality responses to wildfire in Colorado
In 2020, Colorado experienced the most severe wildfire season in recorded history, with wildfires burning 625 357 acres across the state. Two of the largest fires burned parts of Rocky Mountain National Park (RMNP), and a study was initiated to address concerns about potential effects on drinking water quality from mobilization of ash and sediment. The study took advantage of a wealth of...
Authors
David W. Clow, Garrett Alexander Akie, Sheila F. Murphy, Evan J. Gohring
Aquatic carbon export and dynamics in mountain headwater streams of the western U.S. Aquatic carbon export and dynamics in mountain headwater streams of the western U.S.
Mountain headwater streams actively cycle carbon, receiving it from terrestrial landscapes and exporting it through downstream transport and gas exchange with the atmosphere. Although their importance is now widely recognized, aquatic carbon fluxes in headwater streams remain poorly characterized. In this study, aquatic carbon fluxes were measured in 15 mountain headwater streams and...
Authors
David W. Clow, Garrett Alexander Akie, Robert G. Striegl, Colin Penn, Graham A. Sexstone, Gabrielle L. Keith
A call for strategic water-quality monitoring to advance assessment and prediction of wildfire impacts on water supplies A call for strategic water-quality monitoring to advance assessment and prediction of wildfire impacts on water supplies
Wildfires pose a risk to water supplies in the western U.S. and many other parts of the world, due to the potential for degradation of water quality. However, a lack of adequate data hinders prediction and assessment of post-wildfire impacts and recovery. The dearth of such data is related to lack of funding for monitoring extreme events and the challenge of measuring the outsized...
Authors
Sheila F. Murphy, Charles N. Alpers, Chauncey W. Anderson, John R. Banta, Johanna Blake, Kurt D. Carpenter, Gregory D. Clark, David W. Clow, Laura A. Hempel, Deborah A. Martin, Michael R. Meador, Gregory Mendez, Anke Mueller-Solger, Marc A. Stewart, Sean E. Payne, Cara L. Peterman-Phipps, Brian A. Ebel