Chen, Y; Ryder, J; Bastrikov, V; McGrath, MJ; Naudts, K; Otto, J; Ottlé, C; Peylin, P; Polcher, J; Valade, A; Black, A; Elbers, JA; Moors, E; Foken, T; van Gorsel, E; Haverd, V; Heinesch, B; Tiedemann, F; Knohl, A; Launiainen, S; Loustau, D; Ogée, J; Vessala, T; Luyssaert, S: 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, Geoscientific Model Developement, 9, 2951-2972 (2016), doi:0.5194/gmd-9-2951-2016 [Link]

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 sur- face model (Organising Carbon and Hydrology In Dynamic Ecosystems – CANopy), which simulates canopy structure and can be coupled to an atmospheric model using an im- plicit 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 col- lected 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 ever- green 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 cali- brate 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 en- ergy partitioning during winter compared with a single-layer model simulation, the increased model complexity does pro- vide a more detailed description of the canopy micrometeo- rology 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 fre- quencies, and the consequences of biogenic volatile organic compound (BVOC) emissions from the terrestrial ecosystem.

last modified 2016-09-02