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Sarah M Stackpoole

Research Ecologist

Office of the Chief Operating Officer

Office Phone: 303-236-0271
ORCID: 0000-0002-5876-4922

Box 25046
Denver Federal Center
Denver , CO 80225-0046

Supervisor: Brian A Ebel
A nested sampling network on the Colorado (CR) and Missouri Rivers (MR) provided data to assess impacts of large-scale reservoir systems and climate on carbon export. The Load Estimator (LOADEST) model was used to estimate both dissolved inorganic and organic carbon (DIC and DOC) fluxes for a total of 22 sites along the main stems of the CR and MR. Both the upper CR and MR DIC and DOC fluxes increased longitudinally, but the lower CR fluxes decreased while the lower MRs continued to increase. We examined multiple factors through space and time that help explain these flux patterns. Seasonal variability in precipitation and temperature, along with site-level concentration versus discharge relationships proved to...
Categories: Data, Publication; Types: Citation
This product consists of one tabular dataset and associated metadata of water quality information related to rivers, streams, and reservoirs in the Upper Mississippi River watershed between 2012 and 2016. This data release is a part of a national assessment of freshwater aquatic carbon fluxes. Data consist of organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen isotopes, cations, anions, trace metals, and various in situ measurements including: pH, water temperature, air temperature, barometric pressure, dissolved oxygen, turbidity, fluorescent dissolved organic matter, and specific conductance....
Categories: Data, Project; Types: Map Service, OGC WFS Layer, OGC WMS Layer, OGC WMS Service; Tags: Carbon, Fluorescent Dissolved Organic Matter (fDOM), Minnesota, Shingobee, Shingobee Headwaters Aquatic Ecosystems Project, All tags...
Recent studies have found insignificant or decreasing trends in time-series dissolved organic carbon (DOC) datasets, questioning the assumption that long-term DOC concentrations in surface waters are increasing in response to anthropogenic forcing, including climate change, land use, and atmospheric acid deposition. We used the Weighted Regressions on Time, Discharge, and Season (WRTDS) model to estimate annual flow-normalized (FN) concentrations and fluxes to determine if changes in DOC quantity and quality signal anthropogenic forcing at 10 locations in the Mississippi River Basin (MRB). Despite increases in agriculture and urban development throughout the basin, net increases in DOC concentration and flux were...
This product consists of two tabular datasets and associated metadata for major phosphorus fluxes including manure and fertilizer inputs, crop uptake, as well as waste water treatment facility effluent and river export. These are time series data representing water years 1992 to 2012 for watersheds associated with the National Water Quality Program Surface Water Trends project. Dataset 1: Major fluxes and estimated net P balances. Dataset 2: Results of a t-test to determine if site level mean agricultural P balances were significantly above, not different, or below zero. Each site was then assigned to an Accumulation, Equilibrium, or Depletion status categories, respectively. Identification of sites where river...
In support of the USGS LandCarbon project, field observations of stream and lake carbon gas fluxes and other water-quality data were collected from surface waters in the conterminous US. The sampling was designed to cover a variety of geographic, climatic, and environmental settings to better understand the ranges and distributions of carbon gas fluxes from surface waters. Field observations of carbon gas concentration and flux were paired with laboratory measurements of stream chemical characteristics. Locations were derived from field GPS values or from listed coordinates of USGS streamgages located at the sampling site. Discharge data was either measured in the field at the time of sample collection or downloaded...
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