Loop Current Metrics for Skill Assessment of Numerical Ocean Models in the Gulf of Mexico

A simple and robust method for objectively tracking of Loop Current intrusion and identifying eddy separation based on tracking of a fixed sea surface height contour has been developed and tested both with altimeter-derived height fields and with idealized ocean observing system simulations. In this work, Loop Current and Loop Current Eddy metrics based on this tracking technique are used for skill assessment of ocean analysis and reanalysis products in the Gulf of Mexico. The goal is to identify skillful model simulations coincident with deepwater study programs in the Gulf of Mexico to facilitate interpretation of the available observational records at depth. A specific focus is on evaluating the coupling between the observed upper circulation as inferred by assimilation of the altimetric observations versus model analyses and observations of the deep circulation.