Coupled vegetation - atmospheric chemistry model


Role of terrestrial biosphere on the atmospheric chemical composition, Impact of atmospheric chemical composition on vegetation and role of plants on the deposition of chemical compounds at the surface

The terrestrial biosphere is a significant source of reactive chemical compounds, such as isoprene, monoterpenes..., or other volatile organic compounds emitted by plants and mainly leaves, or nitrogen oxides emitted by nitrification and denitrification soil processes. Those compounds play a key role in the atmospheric chemical composition and especially in the ozone cycle or aerosol formation. Moreover, distribution and growth of terrestrial ecosystems is a strong driver of the deposition, and therefore the loss, of atmospheric chemical compounds at the surface. On the other hand, strong and persistent atmospheric concentrations of compounds such as ozone, nitrogen oxides or sulfur doixide can lead to leaf necrosis, decrease in photosynthetic activity and alter plan growth.

There are therefore strong interactions between the terrestrial biosphere and the atmospheric chemical composition, that have to be considered when investigating the evolution of the Earth System. This objective of the coupling between the vegetation model ORCHIDEE and the chemistry-transport model LMDzINCA is to take into account those interactions and add consistency in the IPSL Earth System Model when related to the description of vegetation growth and distribution:

  • Biogenic emissions of reactive compounds (VOCs and NOx) calculated by ORCHIDEE sent to INCA, instead of having an input emission files
  • Distribution of vegetation types prescribed or calculated by ORCHIDEE sent to INCA, corresponding to the time period of interest, instead of having one vegetation distribution file only, read as input file by INCA for any scenario
  • In the purpose of investigating the impact of atmospheric chemical composition on plant growth and distribution: atmospheric concentrations of ozone (in a first step) and other chemical compounds (longer-term) calculated by INCA to be sent to ORCHIDEE where the impact on plant functional types will be calculated (see the PhD work carried out by Thomas Verbeke, LSCE, see this page).

Technical notes

in orchidee


  • Add a routine sechiba_GetFromOrchideeToInca in sechiba.f90. This routine is called from INCA.
    • output :: nvm_inca --> Number of vegetation types
    • output :: veget_max_inca --> Max. fraction of vegetation type (LAI -> infty)
    • input :: field_out_names --> Names for emission variables. Inca give the names to Orchidee
    • output :: fields_out --> fields for emissions variables : to be sent by Orchidee to Inca
  • To be done : an other routine sechiba_GetFromIncaToOrchidee. This routine will be called from ORCHIDEE. And will ask for variables (ozone, and other compounds, atmospheric concentrations) from Inca.
  • Modify declaration of flux in diffuco.

in inca


  • Add a routine surf_chem_atm. This routine call sechiba_GetFromOrchideeToInca
  • Add a module for the variables management surf_chem_mod. This module use getin to read the flux names in inca.def parameter file.
  • Add output file writing all flux and veget_max.
  • (08 august 2012) add title and unit for flux in output file
    flx_iso: Isoprene emissions from vegetation,     kgC/m²/s
    flx_mono: Monoterpene emissions from vegetation, kgC/m²/s
    flx_ORVOC: Other Volatile Organic Compound emissions from vegetation,     kgC/m²/s
    flx_MBO: 2-methyl-3-buten-2-ol emissions from vegetation (mainly pines in America),     kgC/m²/s
    flx_methanol: Methanol emissions from vegetation,     kgC/m²/s
    flx_acetone: Acetone emissions from vegetation,     kgC/m²/s
    flx_formal: Formaldehyde emissions from vegetation,     kgC/m²/s
    flx_acetal: Acetaldehyde emissions from vegetation,     kgC/m²/s
    flx_acetic: Acetic acid emissions from vegetation,     kgC/m²/s
    flx_formic: Formic acid emissions from vegetation,     kgC/m²/s
    flx_no_soil: Nitrogen Oxide emissions from soil, before deposition on canopy,     ngN/m²/s
    flx_no: Net nitrogen Oxide emissions from soil, after deposition on canopy,     ngN/m²/s
    flx_fertil_no: Nitrogen Oxide emission related ONLY to the use of fertilisers, before deposition on canopy,     ngN/m²/s
    veget_max : SurfType_frac, 1

in config

  • Add a parameter file inca.def
    #nombre de flux transferes depuis orchidee vers inca
    #noms des flus a transferer
    # iso -  mono -  ORVOC - MBO -  methanol 
    # acetone - acetal -  formal -  acetic -  formic
    # no_soil -  no -  fertil_no
    emi_FromOrch=iso mono ORVOC MBO methanol acetone acetal formal acetic formic no_soil no fertil_no
  • Add DIFFUCO_OK_INCA=y in orchidee.def

Extract this new configuration

For this you need to add in mod.def

#-H- LMDZORINCA_BCOV  LMDZ4 with ORCHIDEE and INCA (coupled vegetation
#- and chemistry):
#-H- LMDZORINCA_BCOV  ORCHIDEE branches BCOV (close to trunk 951)
#-H- LMDZORINCA_BCOV  INCA branches BCOV (close to trunk 264) 
#-H- LMDZORINCA_BCOV  LMDZ5 LMDZ5/trunk rev 1628
#-H- LMDZORINCA_BCOV  IOIPSL/src svn tags/v2_2_1
#-H- LMDZORINCA_BCOV  libIGCM tag libIGCM_v2.0_beta4
#-C- LMDZORINCA_BCOV  IOIPSL/trunk/src			HEAD			8	IOIPSL/src	modeles
#-C- LMDZORINCA_BCOV  LMDZ5/trunk			1628			11 	LMDZ		modeles
#-C- LMDZORINCA_BCOV  branches/INCA4_BCOV		HEAD			9	INCA3		modeles
#-C- LMDZORINCA_BCOV  tags/libIGCM_v2.0_beta4		HEAD			10	libIGCM		.

And compile with the resolution NMHC_AERxLMD9695-L39


  • first test : one year climatic with this new configuration (LMDZ5 1628 - Orchidee-BCOV - INCA4_BCOV). /ccc/store/cont003/dsm/p86cozic/IGCM_OUT/LMDZORINCA/NMHC_AER/PROD/BCOV/L4OI439.4
Last modified 6 years ago Last modified on 03/26/15 10:34:21

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  • Diapositive1.GIF (149.0 KB) - added by lathiere 9 years ago. Role of terrestrial biosphere on the atmospheric chemical composition
  • Diapositive1.2.GIF (138.5 KB) - added by lathiere 9 years ago. Impact of atmospheric chemical composition on vegetation and role of plants on the deposition of chemical compounds at the surface

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