Document: RIC-3-66-33

Intercomparison of global scale ecological models and field data.

OLSON, R.J.* ¹, K.HIBBARD ², J.M.O.SCURLOCK ¹ and K.J.JOHNSON ¹

Oak Ridge National Laboratory, Oak Ridge, TN 37831-6407 USA ¹
University of New Hampshire, Durham, NH 03824-3525 USA ²

Abstract:
Understanding global-scale ecosystem responses to changing environmental conditions is important both as a scientific question and as the basis for making policy decisions. The confidence in regional models depends on how well the field data used to develop the model represent the region of interest, how well the environmental driving variables represent the region of interest, and how well regional model predictions agree with observed data for the region. To assess how much confidence to place in global model forecasts of terrestrial carbon cycling, the first Ecosystem Model-Data Intercomparison (EMDI) Workshop was held in December 1999. Initial results showed general agreement between model predictions of net primary productivity (NPP) and NPP field measurements but with obvious differences that indicated areas for potential data and model improvement. The EMDI Workshop included 12 biogeochemical, satellite-driven, detailed process, and DVGM model types. Extensive worldwide NPP data were assembled; model driver data including vegetation, climate, and soils were associated with each site; model simulations were performed; and the model-data differences analyzed. NPP and model driver data were compiled for 1200 study sites and for over 1600 0.5-degree grid cells. Comparing the input data with an average NPP from an ensemble of model outputs provided a unique tool to improve NPP data, model driver data, and model processes.

Keywords: NPP terrestrial productivity data models validation

This abstract is being presented at: 3:30 PM in session:
CLIMATE CHANGE