Fluxes

Micrometeorological techniques are used for measuring net exchange of energy and matter between the forest and the atmosphere.

Eddy covariance (EC) method is the most direct and defensible way for measuring the turbulent vertical transport of various gases, heat and aerosol particles.

Three EC flux systems are continuously running at SMEAR II. Two systems (eddy233 and /xwiki/bin/view/SMEAR/The%20SMEAR%20Wikispace/SMEAR%20II%20%28Hyyti%C3%A4l%C3%A4%29/Measurements/Fluxes/eddyTOW/) are located above canopy, and one within canopy (eddy sub-canopy).

Preliminary fluxes are calculated on daily basis and saved into SMEAR disk server as daily files. However, these on-line calculated data are not quality checked, and should not be used for scientific studies. The post-processed and final flux data are calculated every six months, and then saved as monthly files in SMEAR disk server, as well as manually added into SMEAR database.

Flux-gradient method based on the measured vertical concentration profiles are used for flux estimates of volatile organic compounds (VOC) and methane.