To better study the dynamics of the January 2006 warming event we have run the NOGAPS-ALPHA (Navy Operational Global Atmospheric Prediction System- Advanced Level Physics High Altitude) GCM from initial conditions selected throughout January and February of 2005 and 2006. Results are presented from experiments run with different horizontal resolution (T79 and T239) to study the effects of resolved and unresolved gravity wave propagation and drag on the mesospheric winds and temperature. The effects the planetary waves are also examined in terms of EP-flux divergence, mean residual circulation and the momentum balance. While climate fields are used in the upper mesosphere initialization, the upward propagation of the planetary waves allows the mesosphere to develop in a dynamically consistent way in response to the analyzed initial conditions below. In addition to climate-based initialization, NOGAPS-ALPHA results are shown from an improved initialization based on SABER observations assimilated using a high altitude version of NAVDAS (NRL Atmospheric Variational Data Assimilation System). Results from experiments for 2005 and 2006 contrast the differences in the planetary and GW propagation, and in the residual circulations.
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