MsTMIP Motivation

One of the primary approaches for understanding the past, present, and future role of the terrestrial biosphere in the global carbon cycle is the development and application of terrestrial biospheric models (TBMs). These models estimate carbon fluxes through a set of physical and physiological relationships based on our current understanding of processes controlling carbon exchange. Although models vary in their specific goals and approaches, their central role within carbon cycle science is to address key scientific questions ranging from carbon flux attribution (What are the fluxes?), to diagnosis (What are the processes controlling variability?), and to prediction (How will changes in climate and other factors alter future fluxes?). As such, TBMs are the only tool that directly addresses three of the four main overarching questions of the North American Carbon Program (Denning et al. 2005).

The development of individual TBMs has been supported through a variety of programs both within the United States and globally, including the NASA Terrestrial Ecology program and NASA North American Carbon Program. These modeling efforts have brought to light both the promise of modeling approaches for improving our understanding of the carbon cycle, as well as their challenges and uncertainties. Due to the primary focus of ongoing research on individual models, however, there have been limited organized efforts at comparing predictions across TBMs. The MsTMIP is a project designed to provide a consistent and unified modeling framework in order to isolate, interpret, and address differences in process parameterizations among TBMs. This effort requires the development of consistent and optimal environmental driver datasets, the development of a unified intercomparison protocol, as well as coordination of the intercomparison effort across a large number of institutions.