Long-term measurements of surface fluxes above a Scots pine forest in Hyytiälä, southern Finland, 1996–2001

We present nearly six years of measurements of surface fluxes of momentum, sensible heat, water vapour, carbon dioxide and aerosol particles, along with a three-month time series of ozone flux, measured by eddy covariance above a Scots pine forest in southern Finland from April 1996 to December 2001. The results show marked seasonal and diurnal variation and a significant effect of local and remote anthropogenic pollution on CO2 and particle data. The flux of inert CO2 followed environmental factors through plant and soil-microbe metabolism very closely. The flux of reactive O3 depended on the overlapping influences of environmental parameters driving photosynthesis and of the available amount of reaction…