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

Abstract

We have examined lidar and airglow data and National Weather Service analysis fields for a stratospheric sudden warming event in February 1993. The lidar and airglow measurements recorded temperature changes in the mesosphere and lower thermosphere over Eureka, Canada (80°N). In addition, the event was simulated by the National Center for Atmospheric Research TIME‐GCM. The observations, analysis fields, and the simulation results taken together 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 complicates the interpretation for the second of two warming episodes in the upper stratosphere during the event). The sudden warming was associated with cooling observed in the OH airglow and predicted by the model. This cooling preceded the warming in the lower stratosphere.