FOR THE ECOSYSTEM MODEL/DATA INTERCOMPARISON (EMDI)
May 24, 1999
The Ecosystem Model/Data Intercomparison (EMDI) working group held in April, 1999 at the National Center for Ecological Analysis and Synthesis (NCEAS), Santa Barbara has formalized and experimental design and set of timelines and activities for the EMDI activity. As was outlined in a previous email (see =Call_details.rtf) the model/data comparisons will be made for point and gridded (spatial) NPP. The point measurements of NPP will be made for intensive or well-documented Class I/II sites (e.g. site-specific climate, soils information, etc.) and for extensive or Class III sites with less documentation and site-specific information.
The emphasis will be comparisons between individual models and data; therefore, it is not as essential for all models to use the same driver data. However, we will look for general patterns between models, e.g., do all models predict lower NPP values than data for boreal forests? Therefore, we have not provided a common dataset for all possible driver data and modelers may choose to use non-common driver data; however, we request that if a model use non-common data, that these data be provided to EMDI for use by other modelers.
EMDI recognizes that there may be problems in the field data and that feedback from the modelers is an important quality assurance step in compiling appropriate NPP field data for validation and model development. We also hope to state comparisons in neutral terms and not imply that the data are assumed to be truth.
All the NPP field data will be made publicly available in October to compare to model outputs and to the broader modeling community for continued model development. Therefore, only those modeling groups that submit their model simulations to EMDI by 1 October 1999 will be able to claim their model was "blindly" compared to this unique and new collection of NPP data.
The overall design is to initially focus on spatial comparisons with temporal comparisons to be conducted at a second EMDI workshop in spring of 2000. We will be able to initially incorporate a few flux tower sites with NPP data and provide detailed driving variables for many sites. Later this year we plan to assemble flux data from flux towers to compare additional carbon (e.g. NEE) output variables from those models able to simulate a carbon budget. The next iteration of our experimental design will address specific details of suggested spin-up protocols and model runs.
Analysis of output will be performed at the University of New Hampshire by a Masters-level technician supported by the National Center for Ecological Analysis and Synthesis (NCEAS). At the current time, EMDI is working on providing travel funds for one person to attend the November workshop at the University of New Hampshire from each modeling group, HOWEVER, we would like to emphasize that travel funds are not yet secured, and travel may have to be encumbered by individual groups.
Input Data Sets:
By 30 June, the Oak Ridge National Laboratory (ORNL) will release input data sets to drive the model simulations. These data sets include: site, vegtype, soils, climate, and Pathfinder information. Some sites that are included in the 30 June list may be dropped from the final list of sites. We are including all the flux towers and other potential sites with the hope that NPP values will be provided this summer (however, we realize that some sites will lack NPP for the initial comparisons). Data will be provided as ACII, comma separated value (.CSV) files. By early June, ORNL plans to release an example set of information for a typical site using the formats envisioned for the 30 June release.
Basic site information
ORNL will provide a soil description from the site (when available) as well as the following soils data for the 0.5 grid cell containing the site from the Scholes database for each datapoint:
% sand, % silt, % clay, % rock fragments
Water Holding Capacity
Saturated Hydraulic Capacity
pH measured in water
Thermal Diffusivity at 0,15, 100% WHC
0-20 cm, 0-30 cm, 0-100 cm:
Output from Models:
All output variables provided for models will be annual. The only "required" output variable is NPP in gC/m2/y. However, the following list of variables are proposed to address the scientific questions:
Gross Primary Production (GPP)
Aboveground NPP (ANPP)
Belowground NPP (BNPP)
Fine Root NPP
Peak Aboveground Standing Live Biomass
Leaf Area Index (LAI)
Net Ecosystem Productivity (NEP)
Net Biome Productivity (NBP)
Absorbed Photosynthetically Active Radiation (APAR)
Total Autotrophic Respiration (Ra)
Aboveground Autotrophic Respiration
Belowground Autotrophic Respiration
Heterotrophic Respiration (Rh)
Soil Respiration (Rs)
Latent Heat of Evaporation (LE)
Actual Evapotranspiration (AET)
30 June: Release driver data sets for Class I/II and Class III sites to modelers (climatologies, soils, vegtypes)
31 August: release 50% of observed NPP for Class I/II and Class III sites to modelers who have turned in blind simulations (enforced). No model results will be released to other groups. Ancillary data sets for regions will be released to modelers at this time.
1 October: Strict drop-dead date for model results to be turned in. We also request that the modeling groups turn in any documentation of model adjustments, alternative driver data sets and any comments about possible outliers in the data sets they have received (NPP or ancillary). All of the observed NPP data will be made publicly available at this time.
25 October: Graphs of model results will be available on servers (password-protected)
Week of 8 November: EMDI I workshop, tentative location, University of New Hampshire, Durham, NH.
A series of peer-reviewed papers associated with each of the scientific questions will be written based on the results of November meeting, there is a preference for the papers to be published together as a special issue. In addition, the documented data will be publicly distributed.
Current list of Participants:
If you do not see your model group listed below, or, if you would like to have your group removed, please contact Kathy Hibbard.
Model RESPONDENT OF ORIGIN
STOMATE Pierre Friedlingston/Laurent KergoatFrance
Unnamed/DOLY Bill Emanuel U.S.
CASA Chris Field U.S.
PNet John Aber U.S.
LPJ Stephen Sitch/Ben Smith U.K.
AVIM Jinjun Ji Japan
HRBM Tim Reichenau Germany
SIB2 w/Carbon Chris Field/Jörg Kaduk U.S.
CARAIB Bernard Nemry Belgium
SILVAN 2.4 Jörg Kaduk Germany/U.S.
TEM Dave Kicklighter U.S.
VECODE Victor Broukin Germany
GDAY Ross McMurtrie Australia
Others who have responded, but not completed the questionnaire, or are assumed to participate:
BGC Peter Thornton U.S.
CENTURY Becky McKeown/Bill Parton U.S.
HYBRID Andrew Friend U.K.
GLO-PEM Steve Prince U.S.
IBIS Jon Foley U.S.
Recent call sent to:
TRIFFID Peter Cox Germany
MC1 Ron Neilson U.S.
More Information: Contact Kathy Hibbard, GAIM.
DeFries, R.S., Hansen, M., Townshend, J.R.G., and Sohlberg, R., 1998, Global land cover classifications at 8km spatial resolution: the use of training data derived from Landsat imagery in decision tree classifiers, International Journal of Remote Sensing, 19(16), 3141-3168.
Scholes, R.J., Skole, D. and JS Ingram 1995. A global database of soil properties: proposal for implementation. IGBP-DIS Working Paper #10.