FN Archimer Export Format
PT J
TI On the physical mechanisms of the two-way coupling between a surface wave field and a circulation consisting of a roll and streak
BT
AF Suzuki, Nobuhiro
AS 1:1;
FF 1:;
C1 Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, Plouzané 29280, France
C2 UBO, FRANCE
UM LOPS
IN WOS Cotutelle UMR
IF 3.354
TC 5
UR https://archimer.ifremer.fr/doc/00589/70080/68060.pdf
LA English
DT Article
DE ;general fluid mechanics;wave-turbulence interactions;surface gravity waves
AB The governing equations of a surface wave field and a coexisting roll–streak circulation typical of Langmuir circulations or submesoscale frontal circulations are derived to better describe their two-way interactions. The gradients and vertical velocities of the roll–streak circulation induce wave refraction, amplitude modulation and higher-order waves. These changes then produce wave–wave nonlinear forces and divergence of the wave-induced mass transport, both of which in turn affect the circulation. To accurately represent these processes, both a wave theory and a wave-averaged theory are developed without relying on any extrapolation, any spatiotemporal mapping or an approximation that treats the wave-induced mass divergence as being concentrated at the surface. This wave theory finds seven types of current-induced higher-order wave motions. It also determines the wave dynamics such as the governing equation of the wave action density valid in the presence of the complex circulation. The evolution of the wave action density is clearly affected by the upwelling or downwelling. The new wave-averaged theory presents the governing equations of the wave-averaged circulation which satisfies the wave-averaged mass conservation. This circulation is different from the circulation considered to satisfy the mass conservation in the Craik–Leibovich theory, and the difference becomes critical when the wave field evolves due to refraction. In this case, compared to the Craik–Leibovich theory, long waves are more important and also the rolls are more weakly forced.
PY 2019
PD DEC
SO Journal Of Fluid Mechanics
SN 0022-1120
PU Cambridge University Press (CUP)
VL 881
UT 000506237100034
BP 906
EP 950
DI 10.1017/jfm.2019.752
ID 70080
ER
EF