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Keyword: eddy covariance

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.

Temporal dynamics of aerodynamic canopy height derived from eddy covariance momentum flux data across North American flux networks

Publications Posted on: September 28, 2018
Aerodynamic canopy height (ha) is the effective height of vegetation canopy for its influence on atmospheric fluxes and is a key parameter of surface-atmosphere coupling. However, methods to estimate ha from data are limited. This synthesis evaluates the applicability and robustness of the calculation of ha from eddy covariance momentum-flux data.

Data and source code for "A Bayesian model to correct underestimated 3D wind speeds from sonic anemometers increases turbulent components of the surface energy balance"

Datasets Posted on: March 15, 2018
Sonic anemometers are the principal instruments in micrometeorological studies of turbulence and ecosystem fluxes. Common designs underestimate vertical wind measurements because they lack a correction for transducer shadowing, with no consensus on a suitable correction. We present a subset of data collected during field experiments in 2011 and 2013 featuring two or four CSAT3 sonic anemometers.

Sensitivity to low-temperature events: Implications for CO2 dynamics in subtropical coastal ecosystems

Publications Posted on: January 30, 2017
We analyzed the ecosystem effects of low-temperature events (

Factors controlling CO2 exchange on timescales from hourly to decadal at Harvard Forest

Publications Posted on: January 30, 2017
We analyzed 13 years (1992-2004) of CO2 flux data, biometry, and meteorology from a mixed deciduous forest in central Massachusetts. Annual net uptake of CO2 ranged from 1.0 to 4.7 Mg-C ha-1yr-1, with an average of 2.5 Mg-C ha-1yr-1.

Ecosystem resistance in the face of climate change: A case study from the freshwater marshes
of the Florida Everglades

Science Spotlights Posted on: August 17, 2016
The Florida Everglades are composed of a conglomerate of wetland ecosystems that have varying capacities to sequester and store carbon. As shifts in both precipitation and air temperature are expected over the next 100 years as a consequence of climate change, carbon dioxide dynamics in the greater Everglades are expected to change.

Implications of cold-weather events for carbon dioxide dynamics in subtropical coastal ecosystems

Science Spotlights Posted on: August 17, 2016
Low-temperature events (i.e. minimum daily temperatures < 5°C) in subtropical coastal regions can have a strong influence on landscape structure and community composition. In the Everglades region, low-temperature events may become less common, driving shifts in species distributions and carbon (C) dynamics.

Ecosystem resistance in the face of climate change: A case study from the freshwater marshes of the Florida Everglades

Publications Posted on: June 24, 2016
Shaped by the hydrology of the Kissimmee-Okeechobee-Everglades watershed, the Florida Everglades is composed of a conglomerate of wetland ecosystems that have varying capacities to sequester and store carbon. Hydrology, which is a product of the region’s precipitation and temperature patterns combined with water management policy, drives community composition and productivity.

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