Near-inertial oscillations in the deep Gulf of Mexico

Near-inertial oscillations (NIOs) are important for maintaining turbulent mixing that affects ocean circulation, biogeochemistry, and climate. The spatial and temporal variability of NIOs in the deep part of the Gulf of Mexico (GoM) has rarely been reported. In this study, a collection of moored current observations was used to examine the spatiotemporal variability of NIOs in the GoM. In the upper layer (0-800 m), a strong seasonal variability of NIOs appears in the eastern GoM with larger amplitudes in winter than in summer and is attributed to the seasonal variability of surface winds and mixed layer depth. In the bottom layer (within 400 m above the bottom), strong NIOs are found in the middle and eastern GoM and show weaker seasonal variability. While winds still matter for the seasonal variability of NIOs in the bottom layer in the eastern GoM, low-frequency flows generally play a more important role in regulating NIOs through interactions with topography, particularly on the continental slope.

Automated summary

In this study, the spatiotemporal variability of near-inertial oscillations (NIOs) in the deep Gulf of Mexico (GoM) was examined using a collection of moored current observations. Results showed that NIOs in the upper layer (0-800 m) exhibited strong seasonal variability in the eastern GoM, with larger amplitudes in winter than in summer, which was attributed to the seasonal variability of surface winds and mixed layer depth. In the bottom layer (within 400 m above the bottom), strong NIOs were found in the middle and eastern GoM, showing weaker seasonal variability. While winds still played a role in the seasonal variability of NIOs in the bottom layer in the eastern GoM, low-frequency flows and interactions with topography, particularly on the continental slope, played a more important role in regulating NIOs.