讲座简介:

    Heat content changes in the ocean, including hiatus and other phenomena, can be interpreted in terms of heaving associated with adjustment of wind-driven circulation induced by decadal variability of wind. A simple reduced gravity model is used to examine the consequence of adiabatic adjustment of the wind-driven circulation in response to changes in wind stress. The model is formulated for a two-hemisphere basin and for the Southern Oceans. Decadal changes in wind stress forcing can induce three-dimensional redistribution of warm water in the upper ocean. In particular, wind stress change can generate baroclinic modes of heat content anomaly in the vertical direction.

    Intensification of the equatorial easterly can induce cooling in the upper layer and warming in the subsurface layer.  The combination of this kind of heat content anomaly with the general trend of   warming of the whole water column under the increasing greenhouse effect may offer an explanation for the hiatus of surface temperature and the seemingly accelerating subsurface temperature over the past 10-15 years.

    Furthermore, the meridional transport of warm water in the upper ocean can lead to transient meridional overturning circulation and poleward heat flux, and they can make sizable contributions to the observed meridional overturning circulation and poleward heat flux. Thus, adiabatic adjustment of wind-driven circulation plays a key role in the oceanic circulation and climate.