Heat Storage and Transport Processes in the Tropical Atlantic Ocean

Heat storage and transport processes of the tropical Atlantic play an important role in the climate of three continents. The exploration of how the warm water mass maintenance in the equatorial basin depends on various external factors is therefore an important task. This study examines the annual cycle of the warm water mass formation and its transport in the equatorial Atlantic through the interaction of the atmospheric and oceanic boundary layers. Key features of the model are the sea level wind field, equatorial upwelling rate and escape transport of the formed warm water out of the equatorial basin. The model wind field is driven by a distribution of vertical velocities at the top of the atmospheric boundary layer. The wind fields is modeled in January and July with prescribed heat source locations. The model wind fields are tuned to give the most realistic winds at the equator. The equatorial upwelling rate is calculated from a finite amplitude thermocline displacement model which is driven by the model wind field distribution at the equator. Wind field distributions at the equator are also calculated with northward and southward shifted (from climatological July locations) ITCZ and continental heat source locations, the resultant upwelling rates are compared. The annual cycle of the northward heat transport from the equatorial basin is calculated from the divergence of lateral heat transport (obtained from observations). The annual cycle of wind stress curl is then related to the annual heat transport cycle.