ISBA

ISBA (Interaction Sol-Biosphère-Atmosphère) is a land surface model interfaced with atmospheric and hydrological models. ISBA is developed by CNRM in collaboration with various research teams.

ISBA is one compoent of the SURFEX modelling platform, which represents, also, urban surfaces, water bodies and the ocean.

ISBA includes several modules simulating transfers of heat and water in the soil, vegetation, snow, and surface hydrology (deep and surface runoff).

The main options of ISBA



 ISBA-standard

The standard version of ISBA, so called "force-restore", uses a limited number of variables to represent the soil state and the soil-plant-atmosphere exchanges. A single surface temperature characterizes a grid cell composed of vegetated surfaces and bare soil, and is related to a single soil temperature. Regarding the water budget, the soil is represented by either 2 or 3 layers.

Description of the hydrological transfers in the 2-L version of ISBA


Publications :

    • Noilhan, J. and S. Planton, 1989: A simple parameterization of land surface processes for meteorological models. Mon. Weather Rev., 117, 536-549.
    • Mahfouf, J.-F., Manzi, O., Noilhan, J., Giordani, H., Déqué, M. (1995) : The land surface scheme ISBA within the Météo-France climate model ARPEGE. Part I : Implementation and preliminary results. J. Climate, 8, 2039-2057.
    • Noilhan, J. and J.-F. Mahfouf, 1996: The ISBA land surface parameterization scheme. Global and Planetary Change, 13, 145-159.
    • Boone A., J.C. Calvet and J. Noilhan, 1999: Inclusion of a third layer in a land surface scheme using the force restore. J. Appl Meteor, 38(11), 1611-1630.



 ISBA-diffusion

The ISBA multi-layer "diffusion" version explicitly solves the one-dimensional Fourier and Darcy laws throughout the soil. Soil temperature and moisture are calculated on the same vertical grid using 14 layers down to 12m depth. The depths of the 14 layers (0.01m, 0.04m, 0.1m, 0.2m, 0.4m, 0.6m, 0.8m, 1.0m, 1.5m, 2.0m, 3.0m, 5.0m, 8.0m, 12.0m) have been chosen to minimize numerical errors in solving the finite-difference diffusion equations, especially in the first meter of the soil.

For the soil hydrology, the "mixed form" of the Richards equation is used to describe the water-mass transfer within the soil but only in the root zone. Because the computation of soil thermal parameters requires the hydrologic characteristics of each soil layer, the soil moisture under the root zone is extrapolated at each deeper node, assuming a balance of gravity and capillary forces in Darcy’s law.

The soil ice due to soil water phase changes is computed in each soil layer, accounting for the ice sublimation and vegetation insulation effect at the surface. The maximum temperature that allows freezing is related to the soil water pressure head according to the Clausius-Clapeyron relation for water phase equilibrium and using the Gibbs free energy method. This method allows us to determine the maximum liquid water that can freeze as a function of temperature

Note that this 14-layer version is not unchangeable and that the number of layers, whether hydrological or thermal, can also be specified directly by the user.



Description of the 14 layers used by ISBA to simulate soil temeprature and moisture (Decharme et al. 2013)


Publications :

    • Boone, A., Masson, V., Meyers, T., Noilhan, J., Boone, A., Masson, V., et al. (2000). The Influence of the Inclusion of Soil Freezing on Simulations by a Soil–Vegetation–Atmosphere Transfer Scheme. Journal of Applied Meteorology, 39(9), 1544–1569. https://doi.org/10.1175/1520-0450(2000)039<1544:TIOTIO>2.0.CO;2
    • Decharme, B., Boone, A., Delire, C., & Noilhan, J. (2011). Local evaluation of the Interaction between Soil Biosphere Atmosphere soil multilayer diffusion scheme using four pedotransfer functions. Journal of Geophysical Research Atmospheres, 116(20). https://doi.org/10.1029/2011JD016002
    • Decharme, B., Martin, E., & Faroux, S. (2013). Reconciling soil thermal and hydrological lower boundary conditions in land surface models. Journal of Geophysical Research Atmospheres, 118(14). https://doi.org/10.1002/jgrd.50631
    • Decharme, B., Brun, E., Boone, A., Delire, C., Le Moigne, P., & Morin, S. (2016). Impacts of snow and organic soils parameterization on northern Eurasian soil temperature profiles simulated by the ISBA land surface model. Cryosphere, 10(2). https://doi.org/10.5194/tc-10-853-2016



 ISBA-A-gs

ISBA-A-gs jointly simulates photosynthesis and stomatal conductance, together with the response of leaf transpiration to the atmospheric carbon dioxide concentration, and permits to quantify the first-order uncertainties of the response of plants to climate change. The model uses an original description of the plant response to drought, based on two contrasting strategies (avoiding and tolerant).
ISBA-A-gs simulates interactively the above-ground biomass and LAI (the one-sided green leaf area of vascular plants per unit ground surface area), thanks to a simple plant growth model.

Surface fluxes: ISBA-Standard vs. ISBA-A-gs


Publications :

    • Albergel C., Calvet J.-C., Gibelin A.-L., Lafont S., Roujean J.-L., Berne C., Traullé O., Fritz N., 2010 : Observed and modelled gross primary production and ecosystem respiration of a grassland in southwestern France, Biogeosciences, 7, 1657-1668.
    • Calvet J.C., J. Noilhan, J.L. Roujean, P. Bessemoulin, M. Cabelguenne, A. Alioso and J.P. Wigneron, 1998 : An interactive vegetation SVAT model tested against data from six contrasting sites. Agr. For. Meteorol., 92, 92-95.
    • Calvet J.-C., 2000: Investigating soil and atmospheric plant water stress using physiological and micrometeorological data, Agr. For. Meteor., 103, 229-247.
    • Calvet J.-C., Soussana J.-F., 2001 : Modelling CO2-enrichment effects using an interactive vegetation SVAT scheme, Agric. For. Meteorol., 108(2), 129-152.
    • Calvet J.-C., Rivalland V., Picon-Cochard C., Guehl J.-M., 2004 : Modelling forest transpiration and CO2 fluxes - response to soil moisture stress. Agric. For. Meteorol., 124(3-4), 143-156, doi : 10.1016/j.agrformet.2004.01.007.
    • Calvet J.-C., Gibelin A.-L. , Martin E., Le Moigne P., Douville H., Noilhan J., 2008 : Past and future scenarios of the effect of carbon dioxide on plant growth and transpiration for three vegetation types of south-western France, Atmos. Chem. Phys., 8, 397–406.
    • Calvet J.-C., V. Rivalland, C. Picon-Cochard and J.-M. Guehl, 2004: Modelling forest transpiration and CO2 fluxes-response to soil moisture stress, Agric. For. Meteorol., 124,143-156.
    • Gibelin A.L., Calvet J.C., Roujean J.L. Jarlan L. and S. Los, 2006 : Ability of the land surface model ISBA-A-gs to simulate leaf area index at the global scale : Comparison with satellites products. J. Geophys. Res., 111, D18102.



 ISBA-CTRIP

The new large-scale continental surface modelling system ISBA-CTRIP has been included in the SURFEX modelling platform since version 8. It is used in our climate models (atmospheric alone and/or coupled to the ocean) participating in CMIP6 but also for large-scale hydrological applications.

ISBA-CTRIP can be used solely with its physical core, as is the case, for example, in our climate model CNRM-CM6-1, or with the carbon cycle as in our ‘Earth system’ model CNRM-ESM2-1.



 Hydrology

The standard version of ISBA was upgraded in order to better represent surface and deep runoffs for hydrological applications. The main changes have concerned:

  • The sub-grid repartition of precipitation, in order to better represent the precipitation heterogeneity for large grid cells,
  • The sub-grid runoff,
  • The vertical gradient of the soil hydraulic conductivity through an exponential profile.


Publications :

    • Decharme B., Douville H., 2006 : Introduction of a sub-grid hydrology in the ISBA land surface model. Climate Dynamics 26(1), 65 - 78, doi : 10.1007/s00382-005-0059-7
    • Decharme B. and Douville H., 2006 : Uncertainties in the GSWP-2 precipitation forcing and their impacts on regional and global hydrological simulations. Climate Dynamics, 27(7-8), 695-713, doi : 10.1007/s00382-006-0160-6.
    • Decharme B., Douville H., Boone A., Habets F., Noilhan J., 2006 : Impact of an exponential profile of saturated hydraulic conductivity within the ISBA LSM : simulations over the Rhône basin. J. Hydrometeorology , 7, 61-80.
    • Etchevers, P., C. Golaz, F. Habets, J. Noilhan, 2002 :Impact of a climate change on the Rhône river catchment hydrology. J. Geophys. Res., 107(D16), 10.1029/2001JD000490.
    • Habets F., J. Noilhan, C. Golaz, J.-P. Goutorbe, P. Lacarrère, E.Leblois, E. Ledoux, E. Martin, C. Ottlé and D. Vidal-Madjar, 1999: Implementation of the ISBA surface scheme in a distributed hydrological model applied to the Hapex-Mobilhy area. Part I: model and database, J. Hydrol., 217, 75-96.
    • Habets F., J. Noilhan, C. Golaz, J.-P. Goutorbe, P. Lacarrère, E.Leblois, E. Ledoux, E. Martin, C. Ottlé and D. Vidal-Madjar, 1999: Implementation of the ISBA surface scheme in a distributed hydrological model applied to the Hapex-Mobilhy area. Part II: simulation of streamflows and of annual water budget, J. Hydrol., 217, 97-118.
    • Habets, F., A. Boone, J. Noilhan, 2003 :Simulation of a Scandinavian Basin using the diffusion transfer version of ISBA, Gobal and Planetary change, 38, 137-149.
    • Mahfouf, J.-F. and Noilhan, J. (1996) : Inclusion of gravitationnal drainage in a land surface scheme based on the force-restore method. J. Appl. Meteor. 35, 987-992.



 Snow processes

Snow modeling can be addressed with several levels of complexity. The simplest models are generally the most computer time-saving and can be used in weather forecast and climate applications. They represent the snow mantel with a single snow layer and very few prognostic variables. In contrast, the ISBA-ES multi-layer model describes 12 snow layers (default), together with most processes governing the evolution of the snow mantel (accumulation, melting, compaction, refreezing, ...), except for snow metamorphoses, which can be described by more detailed models (e.g. CROCUS).

Solving the surface energy budget: a distinct energy budget for snow


Publications :

    • Douville, H., Royer, J.-F. and Mahfouf, J.-F. (1995a) : A new snow parametrization for the Météo-France climate model. Part I : Validation in stand-alone experiments, Clim. Dyn. 12, 21-35
    • Douville, H., Royer, J.-F. and Mahfouf, J.-F. (1995b) : A new snow parametrization for the Météo-France climate model. Part II : Validation in a 3-D GCM experiments, Clim. Dyn. 12, 37-
    • Bazile, E., M. El Haiti, A. Bogatchev and V. Spiridonov, 2002: Improvement of the snow parametrisation in ARPEGE/ALADIN. In: Proceedings of SRNWP/HIRLAM Workshop on surface processes, turbulence and mountain effects, 22-24 October 2001, Madrid, HIRLAM 5 Project, 14-19.
    • Boone A. and P. Etchevers, 2001: An intercomparison of three snow schemes of varying complexity coupled to the same land surface model: local scale evaluation at an alpine site. J. Hydrol., 2, 374-394.
    • Decharme, B., Brun, E., Boone, A., Delire, C., Le Moigne, P., & Morin, S. (2016). Impacts of snow and organic soils parameterization on northern Eurasian soil temperature profiles simulated by the ISBA land surface model. Cryosphere, 10(2). https://doi.org/10.5194/tc-10-853-2016