Turbulent flux variability and energy balance closure in the TERENO prealpine observatory: a hydrometeorological data analysis

Research output: Contribution to journalResearch articleContributedpeer-review


  • Mohsen Soltani - , Karlsruhe Institute of Technology (Author)
  • Matthias Mauder - , Chair of Meteorology, Karlsruhe Institute of Technology (Author)
  • Patrick Laux - , Karlsruhe Institute of Technology (Author)
  • Harald Kunstmann - , Karlsruhe Institute of Technology, Augsburg University (Author)


The temporal multiscale variability of the surface heat fluxes is assessed by the analysis of the turbulent heat and moisture fluxes using the eddy covariance (EC) technique at the TERrestrial ENvironmental Observatories (TERENO) prealpine region. The fast and slow response variables from three EC sites located at Fendt, Rottenbuch, and Graswang are gathered for the period of 2013 to 2014. Here, the main goals are to characterize the multiscale variations and drivers of the turbulent fluxes, as well as to quantify the energy balance closure (EBC) and analyze the possible reasons for the lack of EBC at the EC sites. To achieve these goals, we conducted a principal component analysis (PCA) and a climatological turbulent flux footprint analysis. The results show significant differences in the mean diurnal variations of the sensible heat (H) and latent heat (LE) fluxes, because of variations in the solar radiation, precipitation patterns, soil moisture, and the vegetation fraction throughout the year. LE was the main consumer of net radiation. Based on the first principal component (PC1), the radiation and temperature components with a total mean contribution of 29.5 and 41.3%, respectively, were found to be the main drivers of the turbulent fluxes at the study EC sites. A general lack of EBC is observed, where the energy imbalance values amount 35, 44, and 35% at the Fendt, Rottenbuch, and Graswang sites, respectively. An average energy balance ratio (EBR) of 0.65 is obtained in the region. The best closure occurred in the afternoon peaking shortly before sunset with a different pattern and intensity between the study sites. The size and shape of the annual mean half-hourly turbulent flux footprint climatology was analyzed. On average, 80% of the flux footprint was emitted from a radius of approximately 250 m around the EC stations. Moreover, the overall shape of the flux footprints was in good agreement with the prevailing wind direction for all three TERENO EC sites.


Original languageEnglish
Pages (from-to)937-956
Number of pages20
JournalTheoretical and applied climatology
Issue number3-4
Publication statusPublished - 1 Aug 2018

External IDs

ORCID /0000-0002-8789-163X/work/163766122


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