Comparing GlobCurrent dataset with numerical results from a high-resolution implementation of the POLCOMS-WAM coupled system under a strong gap wind over the Gulf of Tehuantepec

GlobCurrent provides a variety of datasets aiming to describe global ocean circulation, especially when dealing with large-scale phenomena. It includes surface Stokes drift and geostrophic, Ekman, and total (geostrophic plus Ekman) currents. GlobCurrent uses the CNES-CLS13 mean dynamic topography estimation as well as data from sea surface drifters and wind reanalysis to improve the computation of ocean currents from altimetry data, which represents a significant advance in describing the total ocean current. The aim of this work is to compare the surface GlobCurrent estimates with a coupled ocean–wave numerical simulation (POLCOMS-WAM), drifting buoys, and altimeter observations when dealing with a Tehuano event, i.e., intense (larger than 20 m s ^-1 ) and short duration (around 3–5 days) low-level winds blowing over the Gulf of Tehuantepec, Mexico. There is a good agreement between the wind-driven currents (Ekman currents plus Stokes drift) field from GlobCurrent and that estimated by POLCOMS–WAM, with the largest magnitudes ∼ 0.8 m s ^-1 in the region influenced by the highest winds’ speed. The geostrophic circulation patterns in the Gulf of Tehuantepec are similarly reproduced by GlobCurrent and POLCOMS-WAM. However, some differences were observed in the presence of an anticyclonic eddy located in the western part of the study area. Numerical results exhibit a more symmetrical eddy with geostrophic current speeds that, in agreement with along-track observations, exceed the 1 m s ^-1 . Instead, the geostrophic eddy in GlobCurrent shows velocities of about 0.8 m s ^-1 . As observed through drifting buoys in 2000, numerical results show that the anticyclonic eddy west of the GoT has strong ageostrophic currents related to a cyclogeostrophic balance, which is not included in GlobCurrent. This regional case study provides a guideline for future improvements of GlobCurrent products, in particular for the estimation of geostrophic and total currents.