Elevated Stratopause Events During 2003–2011 Revealed by SABER/TIMED Temperature Observations

Abstract

AbstractThe elevated stratopause (ES) events in the winter (January–March) of 2006, 2009 and 2010 at 70°N are studied based on the SABER/TIMED temperature measurements in the period from 2003 to 2011. In each of these three winters, there suddenly appeared the maximum atmospheric temperature around 80 km between 25 and 85 km in late January–early February, which meant that the stratopause jumped from the normal location (∼50 km) with temperature ∼260 K up to the higher location (∼80 km) with temperature ∼230 K, and this phenomenon was identified as the ES event. As time went on, the ES height decreased gradually and returned to its normal level. Meanwhile the ES temperature increased from ∼230 K to ∼260 K. It is noteworthy that the applied data set indicates that although stratospheric warming occurred in every boreal winter, only after the major sudden stratospheric warming (SSWs) accompanying with the polar vortex splitting, the ES events could occur. Furthermore, in the ES events winter, gravity wave (GW) activity enhancement could be observed at ∼80 km between late January and early February, corresponding to the ES occurrence height and time. After February GW activity became weaker above 75 km and stronger below 75 km when the ES decreased with time. The correlation analyses between GW activity and the ES event indicate the possible contribution of GW activity to the formation of the ES event.