Eddy Covariance
Eddy Covariance - Related Videos
09:05
Measurements of CO2 Fluxes at Non-Ideal Eddy Covariance Sites
0 Views •
2019
The presented protocol uses the eddy covariance method at non-typical locations, applicable to all types of short-canopy ecosystems with limited area, on a currently reforested windthrow site in Poland. Details of measuring site setup rules, flux calculations and quality control, and final result analysis, are described.
01:25
Eddy Currents
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2023
Since eddy currents occur only in conductors, magnets can separate metals from other materials. For example, in a recycling center, trash is dumped in batches down a ramp, beneath which lies a powerful magnet. Conductors in the trash are slowed by eddy currents, while nonmetals in the trash move on, separating from the metals. This works for all metals, not just ferromagnetic ones. Other major applications of eddy currents appear in metal detectors and the braking systems of trains and roller...
01:29
Theory of Attribution II: Kelley's Covariation Theory
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2025
Attribution theory plays a crucial role in social psychology, helping to explain how individuals interpret the causes of behavior. One prominent model within this field is Harold Kelley's covariation theory, which provides a systematic approach to determining whether internal traits or external circumstances drive a person's actions. The model posits that individuals rely on three key types of information—consensus, consistency, and distinctiveness—to make these judgments.Consensus: Comparing...
14:27
Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data
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Cited by 73 •
2013
Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient populations.
06:17
Quantifying the Relative Thickness of Conductive Ferromagnetic Materials Using Detector Coil-Based Pulsed Eddy Current Sensors
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Cited by 10 •
2020
Here, we present a protocol to quantify the relative thickness (i.e., thickness as a percentage with respect to a reference) of conductive ferromagnetic materials using detector coil-based pulsed eddy current sensors, while overcoming the calibration requirement.
FAQs
The method pairs rapid measurements of vertical wind velocity with equally frequent measurements of a scalar, such as carbon dioxide or water vapor. It then calculates the covariance between vertical motion and scalar concentration. This statistical relationship estimates the turbulent flux crossing a defined surface, allowing researchers to quantify atmospheric exchange above an ecosystem.
Covariance identifies whether upward and downward air movements carry different scalar concentrations across the measurement surface. A consistent relationship indicates net turbulent transport, while the magnitude of that relationship provides the flux estimate. This makes it possible to evaluate exchanges of gases, heat, and momentum using coordinated wind and scalar observations rather than measurements of concentration alone.
The approach can assess exchanges involving carbon dioxide, water vapor, heat, and momentum. Carbon dioxide measurements support estimates related to ecosystem photosynthesis and respiration, while water vapor measurements support evapotranspiration analysis. Heat and momentum fluxes contribute to evaluating ecosystem energy balance and atmospheric coupling, extending the method beyond carbon-cycle observations.
Eddy Covariance observes exchange across a defined surface rather than isolating a single leaf, plant, or soil sample. As a result, the measurements integrate activity across an ecosystem area and connect organismal processes with landscape-scale atmospheric exchange. This perspective helps examine how whole forests, wetlands, croplands, and other environments respond to changing conditions.
A study first collects high-frequency measurements of vertical wind velocity and a selected scalar concentration, such as carbon dioxide or water vapor. The observations are then paired and analyzed by calculating their covariance. The resulting turbulent flux estimates can be interpreted for carbon dioxide exchange, evapotranspiration, heat transfer, momentum transfer, or energy balance.
The technique estimates exchange from atmospheric measurements above the ecosystem, so researchers can quantify biological and environmental processes without directly altering vegetation or soil. This is useful when intact conditions matter, particularly for long-term observations. The resulting records can track ecosystem photosynthesis, respiration, evapotranspiration, and energy balance while the study environment remains undisturbed.
Researchers apply the method in forests, wetlands, croplands, and other environments to study carbon cycling and ecosystem responses to climate variability. Because it supports long-term monitoring, the same approach can follow changing exchanges over time and compare how different ecosystem types regulate carbon, water, and energy transfer with the atmosphere.
Carbon dioxide flux estimates provide information about the balance of ecosystem photosynthesis and respiration, while water vapor fluxes inform evapotranspiration. Together with heat and momentum measurements, these data support analysis of ecosystem energy balance. The measurements therefore help relate biological functioning to atmospheric exchange and evaluate responses to climate variability at ecosystem scale.