Atmospheric ozone concentration and flux observations over a pine forest in the Netherlands (Loobos, NL-Loo), 2025.

Since March 2025 ozone concentration and flux observations have been collected at Loobos, NL (52.166446 degN, 5.743575 degE). A fast Eddy-Correlation system measuring at 20 Hz has been installed at the top of the tower (38m), well above the forest canopy. Simultaneously, a slow Thermo Model 49C O3 Analyzer has been installed to measure ozone concentrations at a 1-minute interval. Both instruments are cross-calibrated. F65: 5-minute concentration data to perform the calibration L06_F62: 30-minute ozone fluxes, without application of the calibration, the flux is given in m s-1. F63: Calibration of Fast Ozone Sensor (30 minute time base) Contact information: observations.maq@wur.nl