Fig. 4
From: Role of gravity waves in vertical coupling during sudden stratospheric warmings
Adopted from Pancheva and Mukhtarov (2011, Figures 1, 2)
SSW event and ionospheric variations. The upper panels show the 2007/2008 (left) and 2008/2009 (right) SSWs according to the UK Met Office (UKMO) model. The zonal mean temperatures at 60°N are plotted for the two SSWs at 10 hPa as a function of day number. The ellipse shows the temperature peaks during the warming. In the lower panels, the associated variations of the mean zonal mean electron density (in MHz) retrieved from COSMIC at 300 km during the two warmings are seen.