中文摘要：

通过资料分析，挑选了1965年12月和1968年11月的两次强加拿大型增温作为研究对象来研究加拿大型增温过程中环流的变化及异常。两次加拿大型增温过程中平流层高层的增温不明显，只是在平流层中低层有较弱的增温过程，并且增温过程中所形成的纬向东风较弱，持续的时间较短。从距平场来看，两次加拿大型增温使得平流层极涡环流减弱，但加拿大型增温所造成的环流异常明显要比强爆发性增温所造成的异常强度弱。另外，两次加拿大增温过程中没有发现爆发性增温前的“预先”过程。一般而言，上传的行星波是冬季平流层环流扰动的重要影响因素，两次加拿大型增温过程中第0天前后都有行星波上传的增加，这与爆发性增温有明显的小同。北极涛动指数随时间和高度的变化显示由两次加拿大型增温所造成极涡异常能够形成北极涛动异常的下传，但两次加拿大型增温过程中的北极涛动异常都没有能够到达对流层低层。

英文摘要：

Two Canadian Warmings （CWs） in December 1965 and November 1968 were chosen to investigate the circulation characteristics of CWs. Weak warming was observed at the middle and lower levels of the stratosphere in the two CW cases. Accompanying the weak warming, the westerly in the stratosphere changed to an easterly one, but lasted only a short while. The circulation anomaly in both CW cases was weaker compared to that in the stratospheric sudden warming （SSW）. The ＂pre-conditioned＂ process that was observed in the SSW case was not observed in the two CW cases. As the main factor of the stratospheric disturbance, the upward planetary wave was enhanced prior to and after day 0 of the two CW cases, unlike in the SSW case. Arctic Oscillation （AO） evolution was employed to show the downward stratospheric vortex circulation anomaly. Although the two CWs caused an AO anomaly in the high stratosphere, the AO anomaly barely reached the lower troposphere.