Comparison of the Global Transport Circulations from the NCEP Reanalysis and CCM3

The climatological transport circulation of the troposphere is investigated using 20 years of trajectories computed from two sets of global winds: the NCEP Reanalysis and a standard integration of the National Center for Atmospheric Research Community Climate Model Version 3 (CCM3). The trajectories are used to estimate the climatological (ensemble-mean) Green’s function for the continuity equation for a conservative passive tracer. The Green’s functions are used for quantitative analysis of the structure of the transport circulation in the latitude-height plane, including the seasonal cycle and the degree of hemispheric asymmetry. The Greens functions are also used to make a quantitative comparison of the transport circulations in the NCEP Reanalysis and CCM3.