Altimeter Analysis of Eulerian Velocities & Lagrangian Trajectories In the Interactions of South Africa’s Agulhas & Benguela Current Systems
Event: 2020 Ocean Surface Topography Science Team Meeting (virtual)
Session: Science II: Large Scale Ocean Circulation Variability and Change
Presentation type: Type Forum
The Benguela Current, along SW Africa’s coast often referred to as: “The only Eastern Boundary Current (EBC) that interacts with a Western Boundary Current (WBC, the Agulhas Current).” Altimeter-derived surface velocities and Lagrangian trajectories provide details of those interactions, which move primarily from the Agulhas Current and the Agulhas Bank south of the continent into the Benguela Current and the shelf inshore of the Benguela Current on the SW African coast north of Cape Columbine. We present: (1) the spatial patterns in the long-term mean surface circulation as represented by the recently-releasede CNES CLS18 Mean Dynamic Topography and its associated geostrophic surface currents; (2) seasonal Lagrangian pathways that carry surface water parcels from the Agulhas Bank to the Benguela shelf; and (3) the seasonal progression of Eulerian surface velocity fields that set up the connections that create the trajectories between the Agulhas and Benguela Current Systems. Details of the altimeter’s surface circulation patterns mostly agree with previously published model depictions and complement the surface and subsurface transports produced by a new high-resolution model (see the presentation by Matano et al. in the Large-Scale Circulation session).