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We installed an eddy covariance station on July 10, 2018 at Bison Flat, an acid-sulfate, vapor-dominated area (0.04-km2) in Norris Geyser Basin, Yellowstone National Park, WY to monitor variations in hydrothermal gas and heat emissions. Since then, this station has measured CO2, H2O and sensible and latent heat fluxes, air temperature and pressure, and wind speed and direction on a half-hourly basis. We also measured soil CO2 fluxes and temperatures on a grid using the accumulation chamber method and thermocouple probes, respectively, on July 11-12, 2018 and soil CO2 fluxes only on June 25, 2019. On July 10, 2018 and June 24, 2019, we collected fumarole gas samples for analysis of bulk chemical and carbon (d13C-CO2)...
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This data release includes simulation output from SnowModel (Liston and Elder, 2006), a well-validated process-based snow modeling system, and supporting snow, meteorological, and streamflow observations from the water years 2011 through 2015 (October 1, 2010, through September 30, 2015) across a 3,600 square kilometer model domain in the north-central Colorado Rocky Mountains. For each water year, SnowModel simulations were completed for a (1) baseline simulation, (2) bark-beetle disturbance condition simulation, (3) 2016 - 2035 future climate condition simulation (S1), and (4) 2046 - 2065 future climate condition simulation (S2). Sexstone and others (2018) provide details and summarize findings from each of the...
Water use and carbon acquisition were examined in a northern Utah population of Juniperus osteosperma (Torr.) Little. Leaf-level carbon assimilation, which was greatest in the spring and autumn, was limited by soil water availability. Gas exchange, plant water potential and tissue hydrogen stable isotopic ratio (deltaD) data suggested that plants responded rapidly to summer rain events. Based on a leaf area index of 1.4, leaf-level water use and carbon acquisition scaled to canopy-level means of 0.59 mm day(-1) and 0.13 mol m(-2) ground surface day(-1), respectively. Patterns of soil water potential indicated that J. osteosperma dries the soil from the surface downward to a depth of about 1 m. Hydraulic redistribution...
We integrated soil models with an established ecosystem process model (SIPNET, simplified photosynthesis and evapotranspiration model) to investigate the influence of soil processes on modelled values of soil CO2 fluxes (RSoil). Model parameters were determined from literature values and a data assimilation routine that used a 7-year record of the net ecosystem exchange of CO2 and environmental variables collected at a high-elevation subalpine forest (the Niwot Ridge AmeriFlux site). These soil models were subsequently evaluated in how they estimated the seasonal contribution of RSoil to total ecosystem respiration (TER) and the seasonal contribution of root respiration (RRoot) to RSoil. Additionally, these soil...
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From May to September 2017 measurements of gas and heat emissions were made at Solfatara Plateau Thermal Area, an acid-sulfate, vapor-dominated area in Yellowstone National Park, Wyoming. An eddy covariance system measured half-hourly CO2, H2O and sensible and latent heat fluxes, air temperature and pressure, wind speed and direction and soil moisture. A Multi-GAS instrument measured (0.5 Hz frequency) atmospheric H2O, CO2, SO2 and H2S volumetric mixing ratios, air pressure, temperature and relative humidity and wind speed and direction. Soil temperature at 30 cm depth and CO2 flux were also measured on a grid across a 0.11 km2 area using thermocouple probes and the accumulation chamber method, respectively. The...
In semiarid ecosystems, physiography (landscape setting) may interact with woody-plant and soil microbe communities to constrain seasonal exchanges of material and energy at the ecosystem scale. In an upland and riparian shrubland, we examined the seasonally dynamic linkage between ecosystem CO2 exchange, woody-plant water status and photosynthesis, and soil respiration responses to summer rainfall. At each site, we compared tower-based measurements of net ecosystem CO2 exchange (NEE) with ecophysiological measurements among velvet mesquite (Prosopis velutina Woot.) in three size classes and soil respiration in sub-canopy and inter-canopy micro-sites. Monsoonal rainfall influenced a greater shift in the magnitude...
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Landscape carbon (C) flux estimates are necessary for assessing the ability of terrestrial ecosystems to buffer further increases in anthropogenic carbon dioxide (CO2) emissions. Advances in remote sensing have allowed for coarse-scale estimates of gross primary productivity (GPP) (e.g., MODIS 17), yet efforts to assess spatial patterns in respiration lag behind those of GPP. Here, we demonstrate a method to predict growing season soil respiration at a regional scale in a forested ecosystem. We related field measurements (n=144) of growing season soil respiration across subalpine forests in the Southern Rocky Mountains ecoregion to a suite of biophysical predictors with a Random Forest model (30 m pixel size). We...
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This USGS data release represents supplemental tabular data for an annual groundwater discharge by evapotranspiration (ET) from areas of spring-fed riparian vegetation, Stump Spring and Hiko Springs, Clark County, Nevada, 2016-18. The raw ET dataset contained multiple data gaps that were simulated and gap-filled with the water-level model utility in SeriesSEE, a USGS developed Microsoft Excel® addin. Continuous time-series data, including net radiation, sensible-heat flux, latent-heat flux, and ground-heat flux, from before and after the data gap(s) were used to simulate turbulent fluxes with multivariate regressions and the gramma transform, used for latent heat gaps after precipitation events. ET data were gap...
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From 14 May to 6 October 2016 measurements of gas and heat emissions were made at Bison Flat, an acid-sulfate, vapor-dominated area (0.04-km2) of Norris Geyser Basin, Yellowstone National Park, WY. An eddy covariance system measured half-hourly CO2, H2O and sensible and latent heat fluxes, air temperature and pressure, wind speed and direction, soil moisture and rainfall. A Multi-GAS instrument measured (1 Hz frequency) atmospheric H2O, CO2 and H2S volumetric mixing ratios, air pressure, temperature and relative humidity and wind speed and direction. Soil CO2 fluxes and temperature profiles were also measured on a grid using the accumulation chamber method and thermocouple probes, respectively. These data were used...
We have studied the effects of local topography and canopy structure on turbulent flux measurements at a site located in mountainous terrain within a subalpine, coniferous forest. Our primary aim was to determine whether the complex terrain of the site affects the accuracy of eddy flux measurements from a practical perspective. We observed displacement heights, roughness lengths, spectral peaks, turbulent length scales, and profiles of turbulent intensities that were comparable in magnitude and pattern to those reported for forest canopies in simpler terrain. We conclude that in many of these statistical measures, the local canopy exerts considerably more influence than does topographical complexity. Lack of vertical...
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These data represent net ecosystem exchange of CH4 and CO2 collected using eddy covariance over various time frames. Data were collected from a brackish marsh at Pointe-aux-Chenes State Wildlife Management Area and a tidally influenced freshwater marsh at Salvador State Wildlife Management Area. Both sites were located within the coastal zone of Louisiana, USA.
Soil moisture distribution emerges as a key link between hydrologic and ecologic processes in semiarid grassland and shrubland, as it influences evapotranspiration, respiration, and assimilation. In support, we present three years of data (2002?2004) collected from a semiarid grassland and shrubland within the Sevilleta National Wildlife Refuge of central New Mexico; the two sites are separated by about 5 km. Instrumentation includes an eddy covariance tower and typical micrometeorological devices at both locations. Additionally, the grassland site features six soil moisture profiles and the shrubland site features four soil moisture profiles, with the maximum depth at 52.5 cm. At both sites, most rain falls during...
Coastal marshes take up atmospheric CO2 while emitting CO2, CH4, and N2O. This ability to sequester carbon (C) is much greater for wetlands on a per area basis than from most ecosystems, facilitating scientific, political, and economic interest in their value as greenhouse gas sinks. However, the greenhouse gas balance of Gulf of Mexico wetlands is particularly understudied. We describe the net ecosystem exchange (NEEc) of CO2 and CH4 using eddy covariance (EC) in comparison with fluxes of CO2, CH4, and N2O using chambers from brackish and freshwater marshes in Louisiana, USA. From EC, we found that 182 g C m−2 yr−1 was lost through NEEc from the brackish marsh. Of this, 11 g C m−2 yr−1 resulted from net CH4 emissions...


    map background search result map search result map Carbon acquisition and water use in a Northern Utah Juniperus osteosperma (Utah juniper) population. Gas and heat emission measurements in Norris Geyser Basin, Yellowstone National Park (May-October 2016) SnowModel simulations and supporting observations for the north-central Colorado Rocky Mountains during water years 2011 through 2015 Net ecosystem exchange of CO2 and CH4 from two Louisiana coastal marshes Data release for estimating soil respiration in a subalpine landscape using point, terrain, climate and greenness data Gas and heat emission measurements at Solfatara Plateau Thermal Area, Yellowstone National Park (May-September 2017) Supplemental Evapotranspiration Gap-filled Datasets from Stump Spring and Hiko Springs, Clark County, southern Nevada, 2016-18 Long-term gas and heat emissions measurements, Norris Geyser Basin, Yellowstone National Park Gas and heat emission measurements in Norris Geyser Basin, Yellowstone National Park (May-October 2016) Long-term gas and heat emissions measurements, Norris Geyser Basin, Yellowstone National Park Gas and heat emission measurements at Solfatara Plateau Thermal Area, Yellowstone National Park (May-September 2017) Net ecosystem exchange of CO2 and CH4 from two Louisiana coastal marshes SnowModel simulations and supporting observations for the north-central Colorado Rocky Mountains during water years 2011 through 2015 Supplemental Evapotranspiration Gap-filled Datasets from Stump Spring and Hiko Springs, Clark County, southern Nevada, 2016-18 Data release for estimating soil respiration in a subalpine landscape using point, terrain, climate and greenness data