Near-inertial shear and kinetic energy in the North Atlantic experiment (NISKINe): Moored observations

An 18-month deployment of moored sensors in Iceland Basin allows characterization of near-inertial (frequencies near the Coriolis frequency f with periods of ~14 h) internal gravity wave generation and propagation in a region with an active mesoscale eddy field and strong seasonal wind and heat forcing. The seasonal cycle in surface forcing deepens the mixed layer in winter and controls excitation of near-inertial energy. The mesoscale eddy field modulates near-inertial wave temporal, horizontal, and vertical scales, as well as propagation out of the surface layer into the deep permanent pycnocline. Wind-forced near-inertial energy has the most active downward propagation within anticyclonic eddies. As oceanic surface and bottom boundaries act to naturally confine the propagation of internal waves, the vertical distribution of these waves can be decomposed into a set of “standing” vertical modes that each propagate horizontally at different speeds. The lowest modes, which propagate quickly away from their generation sites, are most enhanced when the mixed layer is deep and are generally directed southward.

Methods
These data were collected as part of the Near-Inertial Shear and Kinetic Energy experiment (NISKINe), which focused on the generation, propagation, and dissipation of near-inertial waves in the Iceland Basin. This specific dataset contains moored observations recorded in the center of Iceland Basin from May 2019 through October 2020. Data were collected on subsurface oceanographic moorings.