Influence Of Wave Transport Flux Residual On Circulation

Mesoscale vortex and large-scale circulation have advection transport and shear-generated effects to oceanic waves, on the contrary oceanic waves has effects to mesoscale vortex and large-scale circulation through wave transport flux residual. Based on the MASNUM(key laboratory of MArine Science and NUmerical Modeling) wave model developed by First Institute of Oceanography of Static Oceanic Administrate, China and POM(Princeton ocean model), BSMT, the effects of wave transport flux residual to temperature in vertical direction, is added to the heat equation in POM as a driving source. Then we analyzes the influence of BSMT on circulation.This study gives a brief introduction of MASNUM and POM and validates that they are well in ocean simulation. For the surface waves, we can decompose wave motion into two componets, i.e. dominant gravitational wave components and the perturbations generated by the background current shear. Analytically express wave transport flux residue as a function of wave-number spectrum and apply BSMT to POM circulation model. BSMT is closely depends on the gradient of background temperature and wave intensity. BSMT changes with significant wave height and its positive or negative value is mainly determined by the background temperature field. In this Pacific Northwest model case, BSMT has the order of 10-7·°C·m·s-1. BSMT has an important influence on the upper ocean, especially near strong currents and some mesoscale vortices. Effects of BSMT can reach 100 m and it can make monthly-average temperatures vary about 0.5 °C. BSMT can increase temperature on upper 50 m about 0.1-0.3°C in shallow waters and near the Kuroshio. The improvements of temperature are closely related to the gradient of background temperature and ocean wave process. The preliminary study indicates that BSMT plays important role for the structure of upper layer of ocean, and further interprets the mechanism of wave-current interaction.