Eddy accumulation

From Glossary of Meteorology

eddy accumulation

A technique for estimating vertical turbulent trace gas fluxes that does not require fast response sensors.

Air is collected in two reservoirs, one when the vertical velocity is positive and the other when the vertical velocity is negative. The volume rate at which the sample is collected is proportional to the magnitude of the vertical velocity. The flux is estimated from the difference in mass collected in each reservoir divided by the collection time.