Abstract
The response time of the southern subtropical oceans to an increase in
the wind stress is examined in a climate model perturbation simulation
where there is an abrupt increase in the wind stress. The ocean response
time is shown to vary among fields: The intensification of the gyres and
vertical movement of isopycnals happens over 5-10 years, while the
change in ideal age, temperature, and salinity in mode and intermediate
waters occurs much slower, with the response time exceeding 100 years at
depths of 500-1000 m. While the response time for ideal age is longer
than that for the surface circulation it is notable that it is much
younger than the ideal age itself. The different response times indicate
that changes in the winds over the southern oceans and in the horizontal
circulation / density structure will occur near simultaneously, but
there may be a substantial lag in subsurface changes from wind changes
and these may persist for decades even if no further changes in the
winds occurs