Characteristics of Robust Mesoscale Eddies in the Gulf of Mexico

Abstract. Although numerous studies on mesoscale eddies in the Gulf of Mexico (GoM) have been conducted, a comprehensive study on their temporal and spatial characteristics is still lacking. In this study, we combine three eddy detection algorithms to detect eddies from the 26-year sea surface height record in the GoM and examine their characteristics. We find distinct characteristics between Loop Current Eddies (LCEs), Loop Current Frontal Eddies (LCFEs), and mesoscale eddies that are not directly related to the Loop Current (LC). Seasonal variability appears in both the LCFEs and non-LCFE cyclonic eddies and shows large uncertainties. More specifically, more LCFEs are formed in January to July than in August to December, likely related to the seasonal variation of the northward penetration of the LC. And the formation of non-LCFE cyclonic eddies shows a biannual variability, which could be linked to the position and strength of the background current in the western GoM. Low-frequency (interannual to multidecadal) variability is also detected. In the eastern GoM, the extent of northward penetration of the LC can affect the generation of LCFEs and result in low-frequency variations. In the western GoM, the low-frequency variability of eddy occurrence and amplitude could be related to the surface circulation strength. This study can serve as an up-to-date reference for eddy-related investigations in the GoM.