Seasonal to Inter-annual Variability of the Advection along the Southwest African Coast

Understanding the dynamics in eastern boundary regions of the world oceans is highly relevant for the success of global climate simulations and predictions. In these regions, the alongshore advection is a key feature since it controls the water mass composition in the upwelling areas by providing a dynamical linkage between the upwelling areas and the tropical oceans. The erroneous representation of the water masses in the South Atlantic eastern boundary region is hypothesized to be one reason for the SST bias in global climate models.

This study examines the seasonal to inter-annual variability of the meridional transport along the southwest African coast (Benguela upwelling system) by analyzing a 12 year record of mooring data and data from a regional general circulation model. The processes driving the alongshore advection, such as the wind stress and the wind stress curl, are investigated by the help of analytical considerations. The question whether the Benguela system is in a Sverdrup balance is addressed.