Mesospheric and lower thermospheric manifestations of a stratospheric warming event over Eureka, Canada (80 degrees N)

We have examined lidar and airglow data and National Weather Service analys is fields for a stratospheric sudden warming event in February 1993. The li dar and airglow measurements recorded temperature changes in the mesosphere and lower thermosphere over Eureka, Canada (80 degrees N). In addition, th e event was simulated by the National Center for Atmospheric Research TIME- GCM. The observations, analysis fields, and the simulation results taken to gether indicate a connection between the stratospheric warming of February 1993 and alternating regions of cooling and warming above the main warming in the lower stratosphere (however, movement of the polar vortex complicate s the interpretation for the second of two warming episodes in the upper st ratosphere during the event). The sudden warming was associated with coolin g observed in the OH airglow and predicted by the model. This cooling prece ded the warming in the lower stratosphere.