Open AccessRegional‐scale evaluation of a land surface scheme from atmospheric boundary layer observations
Author(s) -
Noilhan J.,
Donier S.,
Lacarrère P.,
Sarrat C.,
Le Moigne P.
Publication year - 2011
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2010jd014671
Subject(s) - environmental science , mesoscale meteorology , planetary boundary layer , atmospheric sciences , boundary layer , diurnal cycle , biosphere , atmosphere (unit) , transpiration , scale (ratio) , atmospheric model , meteorology , climatology , geology , geography , physics , botany , cartography , astronomy , biology , thermodynamics , photosynthesis
The study describes an evaluation of three configurations of the Interactions Soil‐Biosphere‐Atmosphere (ISBA) land surface scheme fully coupled with the Meso‐NH mesoscale atmospheric model. The ability of the modeling system to correctly reproduce the screen‐level variables as well as the boundary layer characteristics is examined for more than 30 clear convective days monitored during the CERES 2005 and 2007 field campaigns. For the horizontal resolution considered (8 km), this study shows that the boundary layer characteristics and the low‐level variables are better simulated when the subgrid‐scale surface process variability is simulated explicitly using the so‐called “tiling method.” An additional improvement is brought when the CO 2 diurnal cycle is used interactively because of the physical link between the stomatal conductance used both for CO 2 assimilation and plant transpiration. The parameterization of this link between CO 2 and evaporation fluxes improves the simulation of the Bowen ratio and therefore of the atmospheric boundary layer. The last part of the paper discusses the realism of the simulated regional field of CO 2 when the carbon configuration is activated in the mesoscale model. Large regional variability of CO 2 within the atmospheric boundary layer is found in response to the spatial and seasonal variability of CO 2 surface fluxes with respect to the three main land covers in the area: pine forest, extensive winter (wheat), and summer (maize) crops.