The NCAR Community Climate Model is used to examine the spinup of a model atmosphere from two extremely different initial isothermal rest states: a cold (240 K) state and a warm (310 K) state. Several interesting findings regarding the spinup of the model atmosphere are obtained: (1) The model equilibrium state is independent of the initial condition. (2) The spinup from the cold initial condition is faster than that from the warm initial condition. The former spinup also exhibits an overshooting in the thermal field. (3) The thermal field and baroclinic flow spinup simultaneously. (4) The spinup of the barotropic flow lags behind that of the baroclinic flow and the thermal field. (5) The model tropics spinup faster than the mid-latitudes, and the stratosphere spins up slower than the troposphere. Synoptic and energetics analyses are performed to illustrate these findings and to explain possible mechanisms involved in the model spin up. Emphasis is placed on the adjustment of the model atmosphere by the secondary circulation. ¿ American Geophysical Union 1989