Multiple equilibrium states of the Gulf of Mexico Loop Current

• Published in: Ocean dynamics Vol. 72; no. 11-12; pp. 731 - 740
• Main Authors: Sheremet, Vitalii A., Khan, Arham Amin, Kuehl, Joseph
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-12-2022; Springer Nature B.V
• Subjects: Advection; Aquatic reptiles; Atmospheric Sciences; Boundary currents; Earth and Environmental Science; Earth Sciences; Equilibrium; Fluid- and Aerodynamics; Geophysics/Geodesy; Loop Current; Monitoring/Environmental Analysis; Oceanography; Potential vorticity; Sea surface; Steady state; Vorticity; Western boundary currents; Mexico; Multiple states; Geophysical fluid dynamics; Loop current; Hysteresis
• ISSN: 1616-7341; 1616-7228
• DOI: 10.1007/s10236-022-01534-8

It has been established that idealized western boundary currents, which encounter a gap in their supporting boundary, will assume one of two dominant steady states: a loop current state and a gap leaping state, and that transitions between these states display hysteresis. However, a question of whether the idealized geometries considered to date apply to the Gulf of Mexico Loop Current (LC) remained. Here, the nonlinear potential vorticity advection-diffusions equations are solved, for Gulf of Mexico topography, using Newton’s method. We demonstrate that, in application to the LC in the Gulf of Mexico, the original conclusions do hold and additionally describe peculiarities of the more realistic steady states. The existence of our numerically calculated steady LC states in the actual Gulf of Mexico are supported through analysis of historical sea surface height data, and implications of our results for LC modeling and forecasting are discussed.