Steady Response of a Ventilated Thermocline to Enhanced Ekman Pumping |
| |
Authors: | Atsushi Kubokawa Shang-Ping Xie |
| |
Institution: | (1) Graduate School of Environmental Earth Science, Hokkaido University, Sapporo 060-0810, Japan |
| |
Abstract: | The steady response of the ventilated thermocline to an increase in Ekman pumping is investigated, focusing on the effect
of the mixed layer depth distribution on the subsurface density anomaly. We consider only the subtropical gyre, and the mixed
layer is assumed to be deep in the northwest and shallow elsewhere with a narrow transition zone separating the deep and shallow
mixed layer regions. At the intersection of this narrow transition zone and the outcrop line, low potential vorticity fluid
is subducted into and ventilates the thermocline. In such a situation, an enhancement of the Ekman pumping confined to the
northern subtropical gyre leads to pronounced subsurface cold anomalies in the southern subtropics, which is free of anomalous
forcing. These density anomalies are much greater than those that occur when either the mixed layer depth is zonally uniform
or the Ekman pumping is enhanced in the whole subtropical gyre. They are caused by anomalous changes in the trajectory of
the low potential vorticity fluid in response to anomalous Sverdrup flow.
This revised version was published online in July 2006 with corrections to the Cover Date. |
| |
Keywords: | Oceanic response intensification of westerlies mixed layer depth front subsurface temperature anomaly ventilated thermocline model |
本文献已被 SpringerLink 等数据库收录! |