(1) MODEL AND VERSION
Full model name Atmosphere-Vegetation Interaction Model (AVIM)
Host institution- Institute of Atmospheric Physics, Chinese Academy of Sciences
Key references- Jinjun Ji, 1995, A climate-vegetation interaction model: simulating physical and biological processes at the surface. Journal of
Biogeography, 22, 445-451.
(2) MODEL TYPE
AVIM is a biogeochemical model involving not only land surface physical processes but also eco-physiological processes.
(3) PRIMARY MODEL PURPOSE
To construct physical and eco-physiological process two-way feedback mechanical model to be incorporated within climate model (global or regional ), to study climate- ecosystem interaction.
(4) MODELING APPROACH
AVIM is developed based on the feedback mechanism between the plant growth physiological processes and abiotic environment-atmosphere and soil, that is the accumulation of the exchange of materials (water and carbon dioxide) and energy (radiation, sensible and latent heat) results in plant growth and the changes in morphological and dynamical parameters (leaf area index, albedo and roughness, etc ), in turn to affect significantly the instantaneous physical transfer processes. AVIM is consist of three modules: PHY a soil-vegetation-atmosphere physical transfer module, PLT a plant physiological process module and DYN a module derived surface dynamical parameters from plant morphological parameters.
(5) RESOLUCTION (SPATIAL, TEMPORAL)
Spatial-
0.5*0.5 latitude*longitude grid cell for NPP estimations
Temporal-
30 minutes(10-30 minutes depending on the resolution taken by the atmospheric model) for physical transfer module.
1 hour for physiological module
1 day for biomass accumulation
(6) SPATIAL AND TEMPORAL SCALE(S) AT WHICH THE MODEL RESUTLS SHOULD BE CONSIDERED
Spatial scales: patch to global scales
Temporal scales: daily, seasonal and interannual
(7) PROCESSES AND PROCESS COMPONENTS SIMULATED (e.g. CARBON: GPP, NPP, NEP)
Carbon:
photosynthesis, respiration, allocation of assimilated matter and organic matter decomposition
Water:
a) Soils: infiltration, percolation, runoff, evaporation, transpiration.
b) Energy balance: latent, sensible heat, aet, radiation
c) Snow: snow melting, snow accumulation
d) 'Order' of water balance: rainfall intercepted by canopy, then evaporated from leaf surface and drop down, incoming water infiltrates into soil and forms runoff, soil water sucked by root and transpirated through leaf stomata.
Nitrogen: none
(8) SIMULATED RESERVOIRS
Carbon:
a) vegetation: leaf, stem, and root
b) litter: as a whole
c) SOC: as a whole
Nitrogen: none
a) vegetation: none
b) litter: none
c) SON: none
Soil water:
10 soil layer from surface to 3.5m
(9) CALIBRATION VARIABLE(S) AND METHOD:
Variables: latent and sensible heat flux, CO2 flux net radiation, soil temperature and water content, biomass, LAI, NPP.
Method: observed vegetation and climate data at sites or remote sensing
(10) SCALING OF THE PROCESSES TO THE GRID CELL
using grid cell mean characteristic parameters or to integrated the fluxes in a grid cell.
(11) DISTURBANCE:
grazing, harvest
(12) VEGETATION I/O:
actual
(13) INPUT DRIVERS (CLIMATIC, SITE, VEG, SOILS) AND RESOLUTION (e.g. DAILY, MONTHLY) REQUIRED FOR MODEL INITIALIZATION:
climatic : CO2 concentration, hourly air temperature, humidity,radiation, wind, cloudiness.
vegetation : global PAT 0.5*0.5 latitude*longitude.
soil : global soil texture types in 0.5*0.5 latitude*longitude.
(14) ADDITIONAL COMMENTS:
Several PFTs have been used by modelers. I sugggest that EMDI recommends a PFT for model comparison.