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Keyword: eddy covariance

Data and source code for "Bayesian analyses of seventeen winters of water vapor fluxes show bark beetles reduce sublimation"

Datasets Posted on: December 30, 2020
Sublimation is important to the water cycle of cold, snow dominated ecosystems, many of which have been recently disturbed. In high elevation spruce-fir forests of western North America spruce beetle outbreaks have killed trees, reduced the canopy, and altered the processes that control sublimation. This publication includes the data, source code used for statistical analyses, and Bayesian posterior distributions used in Frank et al.

AmeriFlux site visit report and data for the Glacier Lakes Ecosystem Experiments Site (US-GLE)

Datasets Posted on: December 30, 2020
This report and data summarize the AmeriFlux Tech team site visit to the Glacier Lakes Ecosystem Experiments Site (GLEES) in southeastern Wyoming. For this campaign, the AmeriFlux portable eddy covariance system (PECS) was deployed near the in situ GLEES micro-meteorological sensors.

Improved carbon flux measurements in cold, snow covered ecosystems

Science Spotlights Posted on: October 30, 2020
In cold ecosystems, the annual carbon balance can be dominated by winter respiration. However, the eddy-covariance technique, a common methodology to measure net ecosystem exchange of carbon, can be inaccurate in cold climates due to the effect a warm sensor has on its gas measurement. Often, this error can make an otherwise dormant ecosystem appear as a carbon sink. Recently, RMRS researchers investigated and revised a common correction for this phenomenon.

The FLUXNET2015 dataset and the ONEFlux processing pipeline for eddy covariance data

Publications Posted on: October 02, 2020
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets.

Coordinate rotation-amplification in the uncertainty and bias in non-orthogonal sonic anemometer vertical wind speeds

Publications Posted on: October 02, 2020
Recent research indicates that non-orthogonal sonic anemometers underestimate vertical wind velocity and consequently eddy-covariance fluxes of mass and energy. Whether this is a general problem among all non-orthogonal sonic anemometers, including those calibrated for flow-shadowing effects, is unknown.

A new perspective on the open-path infrared gas analyzer self-heating correction

Publications Posted on: October 02, 2020
Across networks of cold weather sites, eddy covariance measurements of ecosystem fluxes commonly indicate carbon uptake throughout winter, a problem that has been linked to open-path infrared gas analyzer (IRGA) self-heating. Though there is no definitive consensus about this phenomenon, the de facto correction for the prevalent LI-7500 is the methodology of Burba et al.

Scaling Gross Primary Production (GPP) over boreal and deciduous forest landscapes in support of MODIS GPP product validation.

Publications Posted on: June 22, 2020
The Moderate Resolution Imaging Radiometer (MODIS) is the primary instrument in the NASA Earth Observing System for monitoring the seasonality of global terrestrial vegetation. Estimates of 8-day mean daily gross primary production (GPP) at the 1 km spatial resolution are now operationally produced by the MODIS Land Science Team for the global terrestrial surface using a production efficiency approach.

First direct measurements of formaldehyde flux via eddy covariance: Implications for missing in-canopy formaldehyde sources.

Publications Posted on: December 04, 2019
We report the first observations of formaldehyde (HCHO) flux measured via eddy covariance, as well as HCHO concentrations and gradients, as observed by the Madison Fiber Laser-Induced Fluorescence Instrument during the BEACHON-ROCS 2010 campaign in a rural, Ponderosa Pine forest northwest of Colorado Springs, CO. A median noon upward flux of ~80 μg m-2 h-1 (~24 pptv m s-1) was observed with a noon range of 37 to 131 μg m-2 h-1.

Spruce beetles reduce sublimation, causing increasing snowpack in the Wyoming mountains

Science Spotlights Posted on: July 16, 2019
Snow sublimation is a major component of the annual water budget across the Front Range where recent bark beetle outbreaks have dramatically changed the forest canopy structure. A seventeen year study at the Glacier Lakes Ecosystem Experiments Site (GLEES) in Wyoming revealed that sublimation decreased following a spruce beetle outbreak due to reduced canopy intercepted snowfall.

Bayesian analyses of 17 winters of water vapor fluxes show bark beetles reduce sublimation

Publications Posted on: July 10, 2019
Sublimation is an important hydrological flux in cold, snow‐dominated ecosystems. In high‐elevation spruce‐fir forests of western North America, spruce beetle outbreaks have killed trees, reduced the canopy, and altered processes that control sublimation.