Articles | Volume 23, issue 1
Research article
28 Jan 2019
Research article |  | 28 Jan 2019

Using phase lags to evaluate model biases in simulating the diurnal cycle of evapotranspiration: a case study in Luxembourg

Maik Renner, Claire Brenner, Kaniska Mallick, Hans-Dieter Wizemann, Luigi Conte, Ivonne Trebs, Jianhui Wei, Volker Wulfmeyer, Karsten Schulz, and Axel Kleidon

Data sets

Surface energy balance observations at a grassland site in Luxembourg H.-D. Wizemann, I. Trebs, and V. Wulfmeyer

Surface energy balance at a grassland site in Luxembourg modelled by three structurally different evapotranspiration schemes. M. Renner, H.-D. Wizemann, C. Brenner, K. Mallick, I. Trebs, V. Wulfmeyer, K. Schulz, and A. Kleidon

Model code and software

Phaselag: R package to compute the phase lag between two variables M. Renner

R script to reproduce phase lag analysis of the diurnal cycle of evapotranspiration M. Renner

ClaireBrenner/pyTSEB_Renner_et_al2018: OSEB/TSEB code for Renner et al. 2019 C. Brenner

R: A Language and Environment for Statistical Computing R Core Team

Short summary
We estimate the phase lag of surface states and heat fluxes to incoming solar radiation at the sub-daily timescale. While evapotranspiration reveals a minor phase lag, the vapor pressure deficit used as input by Penman–Monteith approaches shows a large phase lag. The surface-to-air temperature gradient used by energy balance residual approaches shows a small phase shift in agreement with the sensible heat flux and thus explains the better correlation of these models at the sub-daily timescale.