Assessment of the HYCOM velocity fields during Agulhas Return Current Cruise 2012

Abstract

We describe a comparison between velocity data (Acoustic Doppler Current Profiler) collected on the Agulhas Return Current (ARC) Cruise of 2012 with model outcomes from the US Navy's operational, assimilating, high-resolution general circulation model: Hybrid Coordinate Ocean Model (HYCOM). The area sampled was a highly chaotic region. The overall differences between the model and in situ velocity fields were 0.35 m/s and 43° at the surface and 0.17 m/s and 30°. While HYCOM accurately simulated the placement of the most energetic and persistent features, including the Agulhas Current, ARC, and a warm core eddy east of ARC, the front was generally misplaced, and the core current speed was under forecast.