Surface turbulent fluxes - 4 French long-term measurement - Processing with EddyPro

This projet brings together four long-term measurement sites to harmonize surface turbulence flux data processing using EddyPro software with standartized settings. By ensuring consistent methodologies across sites, the initiative enhances data comparability for atmospheric and climate research. This effort was made possible through the support of ACTRIS France. The sites include the P2OA platform coupled plain–mountain instrumented platform in southwestern France (60 m mast), the SIRTA instrumented platform in Paris region (50m mast), the meteopoleflux site in an urban grassland in Toulouse (3m) and the Col du Lac Blanc site in the Alps with measurements over snow.

EddyPro* offers numerous combinations of processing parameters, which can lead to variability in results. To ensure consistency and comparability, we have adopted a standardized set of steps, which are detailled below:
-despiking to eliminate strong values, using a threshold on the variance of each parameter
-2d rotation, first rotation aligns the coordinate system with the mean wind, second rotation accounts for the inclinaison of streamlines to yield zero mean vertical wind speed
-detrending, to eliminate the signal of movements slower than turbulence we use a 200s low-pass filter.
-maximum covariance to reduce the error due to a distance difference between the different sensors.
-spectral correction by Moncrieff

*open-source software (LI-COR EddyPro, https://www.licor.com/env/support/EddyPro/software.html)