Stratification variability in the Yucatan Channel and its relationship with the Loop Current System

Frontiers in Marine Science

Marine Science

Susana Higuera-Parra¹  Erick R. Olvera-Prado²  Jorge Zavala-Hidalgo²  Efraín Moreles³ 

[1] Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico;Instituto de Ciencias de la Atmósfera y Cambio Climático, Universidad Nacional Autónoma de México, Mexico City, Mexico;Instituto de Ciencias del Mar y Limnología, Unidad Académica Procesos Oceánicos y Costeros, Universidad Nacional Autónoma de México, Mexico City, Mexico;

关键词: stratification variability;    Yucatan Current;    Loop Current;    Gulf of Mexico;    Empirical Orthogonal Functions;    HYbrid Coordinate Ocean Model;   

DOI  :  10.3389/fmars.2023.1049662

 received in 2022-09-20, accepted in 2023-05-26,  发布年份 2023

来源: Frontiers

【 摘 要 】

The non-seasonal stratification variability in the upper 400 m of the Yucatan Channel (YC) and its relationship with the Loop Current System is studied based on the analysis of long-term timescales not yet resolved in observational studies. Daily outputs from a 22-year free-running simulation performed with the HYbrid Coordinate Ocean Model were used, and the variability modes of the squared buoyancy frequency were estimated using Empirical Orthogonal Functions. Intrinsic ocean dynamics is the primary determinant of the dominant spatial and temporal variability of hydrography and dynamics in the YC. The leading mode, described by a vertical dipole at the western YC section with timescales of 1.5-7.5 years, is mainly determined by the Yucatan Current (YCu) variability. There is a strong connection between YCu dynamics, the upper YC hydrography, the Loop Current (LC) intrusion into the Gulf of Mexico, the detachment of Loop Current Eddies (LCEs), and cyclonic anomalies surrounding the LC. Intense eastward displacements of the YCu are associated with intense stratification anomalies in the western YC, the presence of cyclonic anomalies surrounding the LC southwest margin, detachments of LCEs with larger-than-average diameter, and intense LC retreat; before these eddy detachments, the LC metric values are lower than their average ones. Atmospheric forcing induces more complexity in YC dynamics and the Loop Current System; it produces a significant high-frequency signal that modifies their low-frequency behavior. The relationships found in this work could contribute to a better understanding of the upwelling development on the eastern Yucatan shelf.

【 授权许可】

Unknown   
Copyright © 2023 Higuera-Parra, Moreles, Olvera-Prado and Zavala-Hidalgo