| Abstract |
Several fundamental issues of decadal thermocline dynamics in the extratropical ocean are studied. First, observed large scale upper ocean variability can be understood from an unified viewpoint of planetary wave dynamics. The variability consists of two groups of waves: the 1st baroclinic mode, which propagates largely westward regardless of the mean thermocline circulation (non-Doppler-shift wave) and the 2nd or higher baroclinic modes which tend to follow the circulation. Second, the nature of subduction is studied for an active tracer, such as temperature anomaly. It is found that although the pathway of an active tracer tends to be similar to a passive tracer, its amplitude and speed differ significantly from those of the passive tracer. Third, the impact of a midlatitude Rossby wave packet on the equatorial region is quantified using a simple mass conservation principle. |
