Ecosystem Model-Data Intercomparison Working Group on Data - Synthesis, Formats, and Establishment of an EMDI Server Facility

We propose to conduct a 4-5 day Working Group to promote an Ecosystem Model-Data Intercomparison (EMDI) activity through which, for the first time ever, a wide range of global carbon cycle models will be compared with measured net primary productivity (NPP). The goals of the EMDI are to compare model estimates of terrestrial carbon fluxes to estimates from ground-based measurements. Proposed tasks include finalizing synthesis for ancillary data sets, agreement on data formats, and establishment of computer server/s (one proposed to be located at NCEAS). The proposed Working Group will utilize synthesized data from the Global Primary Productivity Data Initiative (GPPDI) NPP Working Groups 1, 2 and 3 (WG1-WG3) held under support from NCEAS and the International Geosphere Biosphere Program Data and Information System (IGBP-DIS). Methods for synthesizing and extrapolating sparse field observations of above-ground and below-ground NPP were developed during WG1-WG3 to create consistent estimates of total (above + below-ground) NPP for points and regional-scale cells. The results of this work are being presented in a total of 13 peer-reviewed papers, to be submitted to international journals in 3 "waves" (30-Nov-98; 15-Jan-99; 31-Mar-99). The papers incorporate tables of NPP estimates which will also be available as downloadable data sets, initially through the NCEAS server and later (subject to final approval) through the NASA-funded ORNL DAAC at Oak Ridge National Laboratory.

In October 1998, a planning meeting was held in conjunction with the NCEAS WG3 to discuss opportunities to dovetail NPP data sets from the GPPDI with a global model/data intercomparison. It was agreed that the primary question to be addressed by this activity will be to test simulated controls on the carbon budget with the GPPDI data providing model constraints for autotrophic carbon fluxes. The NPP data sets emerging from the GPPDI are derived from both plot and spatially explicit sampling designs, thus enabling a valid comparison between point and area-based models and data. It was proposed that the model-data comparison would need two major working groups to facilitate the comparisons. The first would be a data-intensive workshop where primary (NPP) and ancillary (climate, soils, etc.) data sets would be synthesized, formatted and made available to participating modeling groups. The second working group would entail visualization and analyses of model results. The purpose of this proposal is to solicit support from NCEAS to host the first Working Group of the data-intensive workshop.