Validación de datos de salinidad obtenidos de Copernicus Global Ocean Physics Reanalysis para uso del IPIAP

Abstract

CONDITION FOR PUBLICATION OF PROJECT. The project aims to validate salinity data from the Copernicus global reanalysis along the Ecuadorian coast off Puerto López and Salinas, under the hypothesis that the modeled estimates reproduce local variations but with systematic biases. It is necessary to verify the local representativeness of the salinity reanalysis model data with in-situ measurements provided by the Public Research Institute of Aquaculture and Fisheries, since their validation will strengthen the monthly oceanographic monitoring. For this purpose, salinity profiles were collected with in-situ CTD (2022–2025) following CPPS protocols, and Copernicus model data were obtained for the same period. Subsequently, the modeled salinities were interpolated to compare them with measurements at standard depths and at the desired location, while discrepancies were evaluated using error and correlation metrics. The results indicated that the reanalysis reproduces the observed seasonal cycle with high correlation (R 0.83). However, it presents a negative bias, underestimating salinity and showing greater errors in the surface layer. In subsurface waters (>50 m), the error is minimal (RMSD = 0.08). In conclusion, Copernicus reflects coastal salinity variability, although its surface estimates require local adjustments. Keywords: Global reanalysis, Underestimation, Salinity, Systematic biases, Error metrics.