SGER: Evaluation of Community Climate System Model (CCSM) Constituent Transport Variability

University Of California-Santa Cruz, Santa Cruz CA

Investigators

Abstract

This research uses statistical tools to evaluate the simulation of chemical constituent transport in the Community Climate System Model (CCSM). Traditional methods for evaluating the ability of climate models to represent the transport of constituent gases rests on simple correlation and mean quantity analyses of simulated transports and observed fields. The new approach of the PIs is to use an off-line chemical model that includes the same representations (physics) for advection, convective transfer and boundary layer mixing as used in the CCSM atmospheric model (CAM). The off-line chemical transport model is very efficient, enabling long simulations in relatively short computer wall-clock time. The diagnostics tools to be developed will enable improved analyses of the spatial and temporal variability of the simulated constituent transports, as measured against decades of reanalysis data, including better evaluations of the statistical significance of the model results. Broader Impacts: Improvements in the ability of climate models to simulate the atmospheric transport of radiatively active trace gases is important for future climate projections; a benefit for environmental managers and policy makers in their efforts to understand and manage climate change. The CCSM is used by many university climate scientists who should benefit through the results of this research.