摘要：

An approximate temperature perturbation equation for a continuously stratified deep ocean layer on an equatorial plane is presented. A vertically integrated flow is allowed, which in the present study is forced by uniform upwelling. Solutions with truncated vertical structure are presented which are forced by a representation of localized geothermal heat sources. Solutions exhibit a range of behavior from passive advection to plume, depending on the ratio of barotropic flow speed to long Rossby wave phase speed. Owing to the different phase speeds of the vertical modes, the forced vertical structure is dispersed, which can result in positive and negative temperature anomalies both upstream and downstream of the source. Furthermore, it is clear that the ability of localized sources to influence upstream conditions is enhanced in equatorial regions compared with higher latitudes, where the background flow is better able to advect the temperature perturbations downstream. Depending on the strength of the imposed temperature anomaly at the source, there may or may not be a large-scale reversal of the total flow field. Thus the correlations between temperature, geostrophic shear, and a passive tracer such as 3He can be positive, negative, or zero away from the geothermal source.

展开