Articles | Volume 9, issue 9
Geosci. Model Dev., 9, 2951–2972, 2016
Geosci. Model Dev., 9, 2951–2972, 2016

Model evaluation paper 02 Sep 2016

Model evaluation paper | 02 Sep 2016

Evaluating the performance of land surface model ORCHIDEE-CAN v1.0 on water and energy flux estimation with a single- and multi-layer energy budget scheme

Yiying Chen1,a, James Ryder1, Vladislav Bastrikov1, Matthew J. McGrath1, Kim Naudts1,b, Juliane Otto1,c, Catherine Ottlé1, Philippe Peylin1, Jan Polcher2, Aude Valade3, Andrew Black4, Jan A. Elbers5, Eddy Moors5, Thomas Foken6, Eva van Gorsel7, Vanessa Haverd7, Bernard Heinesch8, Frank Tiedemann9, Alexander Knohl9, Samuli Launiainen10, Denis Loustau11, Jérôme Ogée11, Timo Vessala12,13, and Sebastiaan Luyssaert1,d Yiying Chen et al.
  • 1Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
  • 2Laboratoire de Météorologie Dynamique (LMD, CNRS), Ecole Polytechnique, Palaiseau, France
  • 3Institut Pierre Simon Laplace, Place Jussieu 4, 75010 Paris, France
  • 4Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
  • 5Alterra, Wageningen UR, Wageningen, the Netherlands
  • 6Department of Micrometeorology University of Bayreuth, Bayreuth Center of Ecology and Environmental Research, Bayreuth, Germany
  • 7CSIRO, Marine and Atmospheric Research, Canberra, Australia
  • 8Dept. Biosystem Engineering (BIOSE), University of Liege, Gembloux, Belgium
  • 9Dept. Bioclimatology, Georg-August University of Göttingen, Büsgenweg, Göttingen, Germany
  • 10Natural Resources Institute Finland, Vantaa, Finland
  • 11INRA UMR 1391 ISPA Centre de Bordeaux Aquitaine, Bordeaux, France
  • 12Department of Physics, University of Helsinki, Helsinki, Finland
  • 13Department of Forest Sciences, University of Helsinki, Helsinki, Finland
  • anow at: Research Center for Environmental Changes (RCEC), Academia Sinica, Taipei, Taiwan
  • bnow at: Department of Land in the Earth System, Max Planck Institute for Meteorology, Hamburg, Germany
  • cnow at: Climate Service Center Germany (GERICS), Helmholtz-Zentrum Geesthacht, Hamburg, Germany
  • dnow at: Department of Ecological Sciences, VU University, Amsterdam, the Netherlands

Abstract. Canopy structure is one of the most important vegetation characteristics for land–atmosphere interactions, as it determines the energy and scalar exchanges between the land surface and the overlying air mass. In this study we evaluated the performance of a newly developed multi-layer energy budget in the ORCHIDEE-CAN v1.0 land surface model (Organising Carbon and Hydrology In Dynamic Ecosystems – CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an implicit coupling procedure. We aim to provide a set of acceptable parameter values for a range of forest types. Top-canopy and sub-canopy flux observations from eight sites were collected in order to conduct this evaluation. The sites crossed climate zones from temperate to boreal and the vegetation types included deciduous, evergreen broad-leaved and evergreen needle-leaved forest with a maximum leaf area index (LAI; all-sided) ranging from 3.5 to 7.0. The parametrization approach proposed in this study was based on three selected physical processes – namely the diffusion, advection, and turbulent mixing within the canopy. Short-term sub-canopy observations and long-term surface fluxes were used to calibrate the parameters in the sub-canopy radiation, turbulence, and resistance modules with an automatic tuning process. The multi-layer model was found to capture the dynamics of sub-canopy turbulence, temperature, and energy fluxes. The performance of the new multi-layer model was further compared against the existing single-layer model. Although the multi-layer model simulation results showed few or no improvements to both the nighttime energy balance and energy partitioning during winter compared with a single-layer model simulation, the increased model complexity does provide a more detailed description of the canopy micrometeorology of various forest types. The multi-layer model links to potential future environmental and ecological studies such as the assessment of in-canopy species vulnerability to climate change, the climate effects of disturbance intensities and frequencies, and the consequences of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem.

Short summary
In this study, we compiled a set of within-canopy and above-canopy measurements of energy and water fluxes, and used these data to parametrize and validate the new multi-layer energy budget scheme for a range of forest types. An adequate parametrization approach has been presented for the global-scale land surface model (ORCHIDEE-CAN). Furthermore, model performance of the new multi-layer parametrization was compared against the existing single-layer scheme.