LI-7200 Enclosed CO₂/H₂O Analyzer

Eddy Covariance

Eddy Covariance Resources:

A Brief Practical Guide to Eddy Covariance Flux Measurements

by G. Burba and
D. Anderson

Available for Free Download

Sonic Integration

Connectivity & Datalogging

EddyPro Software

Eddy Covariance Training

For more information on the theory behind the eddy covariance method, view the Ecosystem Gas Exchange application page:

Eddy Covariance

The scientific methods for characterizing greenhouse gas flux are well developed theoretically and have been refined through years of research. Eddy covariance is one of the most widely used and theoretically defensible techniques for measuring sensible heat, latent heat, and trace gas exchange between ecosystems and the atmosphere.

In its simplest form, flux refers to the amount of something that moves through a defined area in a defined time. For example, the flux of CO₂ is the sum of all CO₂ exchanges over a specified time period, over a specified area. In order to characterize this accurately, the instrumentation involved must be able to resolve the concentration of CO₂ and vertical air movements at the finest spatial and temporal scale that contributes to the flux.

The LI-7200 is optimized for the eddy covariance technique. With the eddy covariance method, the flux, Fc of gas C (e.g. CO₂) is given by where c' is the density fluctuations of the gas (mmol/m³), and w' is the vertical wind velocity fluctuations (m/s). The LI-7200 has the high speed and precision required for this method. The flux of CO₂ and H₂O is obtained from the vertical wind speed (measured with a sonic anemometer) and the concentration of the gas (measured with the LI-7200).