Comparison of ozone fluxes over grassland by gradient and eddy covariance technique

Abstract

Ozone flux measurements over vegetation are important to estimate surface losses and ozone uptake by plants. The gradient and eddy covariance flux technique were used for measurements over grassland at a flux-monitoring site in southern Scotland during August 2007. The comparison of the two methods shows that the aerodynamic flux-gradient method provides very similar long-term average fluxes of ozone as the eddy covariance method. The eddy covariance technique is better at capturing diurnal cycles and short-term changes, but the comparison of two fast analysers illustrate that there can be considerable measurement uncertainty