A New Post-Hoc Method to Reduce the Energy Imbalance in Eddy Covariance Measurements

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Weijie Zhang - , Max Planck Institute for Biogeochemistry, Ghent University (Author)
  • Jacob A. Nelson - , Max Planck Institute for Biogeochemistry (Author)
  • Diego G. Miralles - , Ghent University (Author)
  • Matthias Mauder - , Faculty of Environmental Sciences, Chair of Meteorology, TUD Dresden University of Technology (Author)
  • Mirco Migliavacca - , European Commission Joint Research Centre Institute (Author)
  • Rafael Poyatos - , CREAF - Centre for Ecological Research and Forestry Applications, Autonomous University of Barcelona (Author)
  • Markus Reichstein - , Max Planck Institute for Biogeochemistry, Michael Stifel Center Jena for Data-driven and Simulation Science (Author)
  • Martin Jung - , Max Planck Institute for Biogeochemistry (Author)

Abstract

Latent and sensible heat flux observations are essential for understanding land–atmosphere interactions. Measurements from the eddy covariance technique are widely used but suffer from systematic energy imbalance problems, partly due to missing large eddies from sub-mesoscale transport. Because available energy drives the development of large eddies, we propose an available energy based correction method for turbulent flux measurements. We apply our method to 172 flux tower sites and show that we can reduce the energy imbalance from −14.99 to −0.65 W m−2 on average, together with improved consistency between turbulent fluxes and available energy and associated increases in r2 at individual sites and across networks. Our results suggest that our method is conceptually and empirically preferable over the method implemented in the ONEFlux processing. This can contribute to the efforts in understanding and addressing the energy imbalance issue, which is crucial for the evaluation and calibration of land surface models.

Details

Original languageEnglish
Article numbere2023GL107084
JournalGeophysical research letters
Volume51
Issue number2
Publication statusPublished - 28 Jan 2024
Peer-reviewedYes

External IDs

ORCID /0000-0002-8789-163X/work/163766092

Keywords

Keywords

  • available energy flux, Bowen-ratio correction, eddy covariance, energy balance closure, latent and sensible heat flux, sub-mesoscale transport