Near-Inertial Internal Gravity Waves in the Ocean.
We review the physics of near-inertial waves (NIWs) in the ocean and the observations, theory, and models that have provided our present knowledge. NIWs appear nearly everywhere in the ocean as a spectral peak at and just above the local inertial period f, and the longest vertical wavelengths can propagate at least hundreds of kilometers toward the equator from their source regions; shorter vertical wavelengths do not travel as far and do not contain as much energy, but lead to turbulent mixing owing to their high shear. NIWs are generated by a variety of mechanisms, including the wind, nonlinear interactions with waves of other frequencies, lee waves over bottom topography, and geostrophic adjustment; the partition among these is not known, although the wind is likely the most important. NIWs likely interact strongly with mesoscale and submesoscale motions, in ways that are just beginning to be understood.
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093; email: malford@ucsd.edu.
Matthew H
MH
Alford
Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093; email: malford@ucsd.edu.
Jennifer A
JA
MacKinnon
School of Fisheries and Ocean Sciences, University of Alaska at Fairbanks, Fairbanks, Alaska 99775.
Harper L
HL
Simmons
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, Oregon 97331.
Jonathan D
JD
Nash
D006112:Gravitation; D012623:Seawater / Q000737:chemistry*; D014872:Water Movements; D014919:Wind
climate; internal gravity waves; mixing; near-inertial waves; turbulence