Matrix-based Model Intercomparison Project (MatrixMIP) to analyze across-model spread in simulating peatland carbon dynamics

We consolidated the C module of eight land models (i.e., TEM, DALEC2, TECO, FBDC, CASA, CENTURY, CLM4.5, and ORCHIDEE) into a unified matrix form. These eight models differ largely in complexity, with the number of C pools ranging from 2 to 101. We then used the eight matrix models to simulate ecosystem C dynamics under ten experimental treatments, which are a factorial combination of two atmospheric CO2 levels (i.e., ambient, and elevated to 900 ppm) and five temperature levels (i.e., +0, +2.25, +4.5, +6.75, and +9.0 oC), in a spruce peatland in northern Minnesota, USA. For each treatment, the eight matrix models were driven by same gross primary production (GPP) and environmental variables (e.g., soil temperature and water content), which were measured either in the field or simulated by the validated Terrestrial ECOsystem (TECO) model.