2003-2011年平流层顶抬升事件的SABER/TIMED观测

利用2003-2011年的SABER/TIMED温度数据观测发现，在2006年、2009年和2010年北半球高纬（70°N）的冬季（1-3月）发生了“平流层顶抬升”.在这3次事件中，1月末-2月初的~50 km和~80 km高度处分别出现了温度的极大值~260 K和~230 K，即平流层顶的高度突然由原来的50 km左右上升至80 km左右，这就是平流层顶抬升事件；随着时间的推移，抬升的平流层顶的高度逐渐下降直至恢复到原有位置，与此同时其温度由~230 K上升至~260 K.值得注意的是，虽然在极区的每年冬天都发生平流层突然增温事件，但是只在伴随着极涡分裂的平流层突然增温事件后出现平流层顶抬升.此外，在发生平流层顶抬升事件的冬季里，高纬的重力波活动在1月末-2月初的~80 km高度处突然增强，对应着平流层顶的抬升时间和高度；在2月份之后，重力波活动在75 km以下逐渐增强、在75 km以上逐渐减弱，同时抬升的平流层顶也不断下降.通过重力波活动与平流层顶抬升事件的相关性分析，表明重力波活动可能对平流层顶的抬升有重要影响.

Elevated stratopause events during 2003-2011 revealed by SABER/TIMED temperature observations

The 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.