Eddy Covariance (EC) technique is a direct micrometeorological flux measurement method, which provides exchange rates (fluxes) of energy, gases and aerosol particles at ecosystem scale (100 m - 1 km) and high temporal resolution (typically 30-min time step). Among micrometeorological methods, EC is the one with the least assumptions. The Micrometeorology group of the Division of Atmospheric Sciences of University of Helsinki has done a lot of research in the field of Eddy Covariance fluxes since 1996.

Eddy covariance system Generally speaking high frequency (10 or 20 Hz) data are measured at certain height above the surface by using fast sensors for wind components and air temperature (three dimensional sonic anemometer) and for scalars, like gas and aerosol concentration (e.g. gas analyzer). EC fluxes are obtained from the high frequency data by means of several mathematically complex post-processing steps (Aubinet et al., 2000). From the long time series of flux data, the annual and interannual variations and the environmental factors (like long cloudy periods, drought, the length of snow-ice cover, heat wave) affecting them can be deduced. method is one of the most direct and defensible ways to measure turbulent fluxes.