Data Archive for the PIK IGBP-GCTE DGVM Intercomparison
Project
This archive documents all data that have been generated in connection with the
"Intercomparison of Dynamic Global Vegetation Models" carried out under the auspices
of the International Geosphere Biosphere Programme, core project Global Change
and Terrestrial Ecosystems, at the Potsdam Institute for Climate Impact Research.
The original results of this comparison are published in: Cramer W, Bondeau
A, Woodward FI, Prentice IC, Betts RA, Brovkin V, Cox PM, Fisher V, Foley JA,
Friend AD, Kucharik C, Lomas MR, Ramankutty N, Sitch S, Smith B, White A &
Young-Molling C 2001 Global response of terrestrial ecosystem structure and function
to CO2 and climate change: results from six dynamic global vegetation
models. Global Change Biology7(4):357-373.All data may be downloaded from this server. Please ensure
that proper reference is being made to the individual modelling teams.
Requests for further information should be made to
Wolfgang Cramer
Potsdam Institute for Climate Impact
Research
PO Box 60 12 03, D-144 12 Potsdam, Germany
Tel.: +49-331-2882521, Fax: +49-331-2882600
E-mail: Wolfgang.Cramer -at- pik-potsdam.de
Input data used for DGVM calculations
http://www.pik-potsdam.de/data/dgvm_gcb_2000/input
These data are derived from the HadCM2-SUL climate model but have received
additional processing for the purposes of the DGVM model comparison. The
basics of this processing are described in the paper. The data should NOT
be considered a realistic climate data set for modern climate.
Monthly input climate data, derived from climate model output
| variable |
code |
| Minimum temperature (°C) |
tmin |
| Maximum temperature (°C) |
tmax |
| Precipitation (mm) |
prec |
| Sunshine (% hours of possible) |
suns |
| Relative humidity (%) |
humi |
| Total incoming short wave radiation (W m-2) |
swrd |
For each of these variables, there are
31 annual data files for the "spinup years" (named "1830" – "1860"
for convenience – they are to be considered scenario data for a stable
preindustrial climate)
239 annual data files for the years with processed output from the transient
climate model simulation (named "1861" – "2199" – this is based on observed
or estimated CO2 concentrations as external forcing of the model,
the data reflect therefore not the actual year-by-year climate fluctuations)
100 annual data files for the years of the abrupt stabilisation scenario
based on simulated conditions in 2099 (named "2100" – "2199")
File names:
e.g. "prec1861.dat" (precipitation for 1861)
File format:
1631 lines for 1631 grid cells
12 columns with the monthly values
The south-west coordinates of the 1631 grid cells are provided in the file
landpix.dat
The 370 annual data files for each climate variable are tar-archived
and compressed (names see table above)
All variables (to the exception of humi) are constructed by first calculating
climate model anomalies in relation to the monthly long term means of the
simulated years 1931-60. These anomalies were then applied to an observed
climatology for 1931-60. The result therefore retains the spatial pattern
of average observed climate in combination with the temporal dynamics of
the climate model.
The annual CO2 concentrations (ppm) from historical observations
and for a future scenario, from 1861 to 2099, are provided in the file
co2sim.dat.
Output data from the six participating DGVMs:
File locations:
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/hybrid
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/ibis
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/lpj
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/sdgvm
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/triffid
http://www.pik-potsdam.de/data/dgvm_gcb_2000/output/vecode
Variables:
All variables are listed in separate files. Biomass, NPP and LAI are given
separately for each plant functional type (pft), using the pfts: C3
grass ("3"), C4 grass ("4"), deciduous trees ("d"), evergreen
trees ("e").
biomass ("bio", in kg C m-2)
net primary productivity ("npp", in kg C m-2 y-1)
leaf area index ("lai")
soil carbon ("soil", in kg C m-2)
runoff ("runo", in m y-1)
Experiments:
climate change only ("T")
CO2 increase only ("C")
CO2 increase & climate change ("CT")
File names:
e.g. ibio3_C.dat: 'i' for model IBIS; 'bio3' for C3 grass
biomass; 'C' for experiment C
File format:
ASCII
1631 lines for 1631 grid cells (ice-free land cells in the HadCM2 climate
model, the size of these cells is 3.75 degrees in longitudinal and 2.5
degrees in latitudinal direction)
Each line contains 341 space-delimited data columns:
longitude of SW corner (degrees, with decimals)
latitude of SW corner (degrees, with decimals)
output data for the 339 years of the simulation (1861-2199)
Figures
http://www.pik-potsdam.de/data/dgvm_gcb_2000/figs
this directory contains ps and eps files of figures 2-3-4-5-6-7-8
Processed DGVM Output for the figures
(The technical description of these data is located at the top of the files)
Vegetation classification for figure 2:
http://www.pik-potsdam.de/data/dgvm_gcb_2000/figs/processed/clafig2.dat
Zonal NEP for figure 6:
http://www.pik-potsdam.de/data/dgvm_gcb_2000/figs/processed/nepzonalfig6.dat
(last updated on 4.1.07)