Internal Waves in the East Australian Current. Issue 24 (17th December 2017)

• Record Type: Journal Article
• Authors: Alford, Matthew H.; Sloyan, Bernadette M.; Simmons, Harper L.
• Is Part Of: Geophysical research letters. Volume 44:Issue 24(2017)
• Page Start: 12, 280
• Page End: 12, 288
• Publication Date: 2017-12-17
• Subjects: internal waves; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL075246
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: Internal waves, which drive most ocean turbulence and add "noise" to lower‐frequency records, interact with low‐frequency current systems and topography in yet poorly known ways. Taking advantage of a heavily instrumented, 14 month mooring array, internal waves in the East Australian Current (EAC) are examined for the first time. Internal wave horizontal kinetic energy ( H K E ) is within a factor of 2 of the Garrett‐Munk (1976) spectrum. Continuum internal waves, near‐inertial waves, and internal tides together constitute a significant percentage of the total velocity variance. Mode‐1 internal tide energy fluxes are southward and much smaller than energy times group velocity, consistent with reflection at the continental slope of incident waves generated from near New Caledonia and the Solomon Islands. Internal tide H K E is highly phase variable, consistent with refraction by the variable EAC. Mode‐1 near‐inertial wave energy fluxes are of comparable magnitude and are equatorward and episodic, consistent with generation by storms farther poleward. These processes are considered together in the complex environment of the EAC. Key Points: Internal waves are present in the EAC, with continuum levels twice the GM spectral level Internal tides are reflective and nonstationary Near‐inertial waves are equatorward propagating and quite energetic, consistent with distant radiation from storms