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

Abstract

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 (80øN). 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.

Dynamical coupling of the stratosphere and mesosphere in the 2002 Southern Hemisphere major stratospheric sudden warming

“…The NCEP driven model at 10 hPa has been used by Walterscheid et al [2000] to study the mesospheric and lower thermospheric (MLT) impact of SSW for the 1993 episode and another version of the model, which is flux-coupled with the NCAR Community Climate Model (CCM3) was used by Liu and Roble [2002] to study a self-generated SSW episode. The GW forcing is parameterized based on the linear saturation theory by Lindzen [1981].…”

“…[2] The mesospheric temperature and wind at high winter latitudes can change significantly during stratospheric sudden warming (SSW) events [e.g., Walterscheid et al, 2000;Liu and Roble, 2002;Cho et al, 2004], characterized by mesospheric cooling, deceleration or reversal of the mesospheric zonal wind, and change of the residual circulation. Mesospheric cooling [Hernandez, 2003;T.…”

Vertical and interhemispheric links in the stratosphere-mesosphere as revealed by the day-to-day variability of Aura-MLS temperature data

“…The vertical connection has been widely studied (e.g. Jacobi et al, 1997Jacobi et al, , 2003Walterscheid et al, 2000;Hoffmann et al, 2002;Chshyolkova et al, 2005;Dowdy et al, 2007;Manson et al, 2008), but will be highlighted by the use of the larger observational dataset in this work.…”

Stratospheric warming influence on the mesosphere/lower thermosphere as seen by the extended CMAM

“…The effect of SSW on the upper mesosphere and thermosphere was further examined by Shepherd and Shepherd (2011) employing WINDII (Wind Imaging Interferometer) (Shepherd et al, 1993) satellite observations of O( 1 S) dayglow volume emission rate (VER) in the altitude range from 80 to 300 km and from 50 to 70 • N, observed during the stratospheric warming event in February 1993 (Whiteway and Carswell, 1994;Shepherd et al, 1999;Walterscheid et al, 2000). Of particular interest was the response of thermospheric O( 1 S) dayglow as a proxy for SSW-induced variations in the O volume mixing ratio.…”