... In the Garrett–Munk spectrum the shear spectral slope changes from white to +2 below a vertic... more ... In the Garrett–Munk spectrum the shear spectral slope changes from white to +2 below a vertical mode number j*. GM76 uses j* = 3. Levine et al. ... 1981; Gregg et al. 1993; Winkel 1998) and in the middle atmosphere (Smith et al. 1987; Fritts 1989; Allen and Vincent 1995). ...
Strong internal tide generated currents and rough topography lead to intense mixing at the bottom... more Strong internal tide generated currents and rough topography lead to intense mixing at the bottom and the sloping sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
Strong internal tide generated currents and rough topography lead to intense mixing at the bottom... more Strong internal tide generated currents and rough topography lead to intense mixing at the bottom and the sloping sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
The inertial subrange Kolmogorov constant for the Lagrangian velocity structure function C0 is re... more The inertial subrange Kolmogorov constant for the Lagrangian velocity structure function C0 is related to the inertial subrange constant for the Lagrangian acceleration spectrum β by C0=πβ. However, Rλ must be greater than about 105 for the inertial subrange of the structure function to be sufficiently wide to accurately determine C0, while values of Rλ greater than 102 are sufficient to determine β. Taking these Rλ limitations into account, the only two known high-quality independent measurements of C0 are 5.5 and 6.4.
Large-amplitude (100–200 m) nonlinear internal waves (NLIWs) were observed on the continental slo... more Large-amplitude (100–200 m) nonlinear internal waves (NLIWs) were observed on the continental slope in the northern South China Sea nearly diurnally during the spring tide. The evolution of one NLIW as it propagated up the continental slope is described. The NLIW arrived at the slope as a nearly steady-state solitary depression wave. As it propagated up the slope, the wave propagation speed C decreased dramatically from 2 to 1.3 m s−1, while the maximum along-wave current speed Umax remained constant at 2 m s−1. As Umax exceeded C, the NLIW reached its breaking limit and formed a subsurface trapped core with closed streamlines in the coordinate frame of the propagating wave. The trapped core consisted of two counter-rotating vortices feeding a jet within the core. It was highly turbulent with 10–50-m density overturnings caused by the vortices acting on the background stratification, with an estimated turbulent kinetic energy dissipation rate of O(10−4) W kg−1 and an eddy diffusivity of O(10−1) m2 s−1. The core mixed continually with the surrounding water and created a wake of mixed water, observed as an isopycnal salinity anomaly. As the trapped core formed, the NLIW became unsteady and dissipative and broke into a large primary wave and a smaller wave. Although shoaling alone can lead to wave fission, the authors hypothesize that the wave breaking and the trapped core evolution may further trigger the fission process. These processes of wave fission and dissipation continued so that the NLIW evolved from a single deep-water solitary wave as it approached the continental slope into a train of smaller waves on the Dongsha Plateau. Observed properties, including wave width, amplitude, and propagation speed, are reasonably predicted by a fully nonlinear steady-state internal wave model, with better agreement in the deeper water. The agreement of observed and modeled propagation speed is improved when a reasonable vertical profile of background current is included in the model.
Strong internal tide generated currents and rough canyon topography lead to intense mixing at the... more Strong internal tide generated currents and rough canyon topography lead to intense mixing at the bottom and the sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
... In the Garrett–Munk spectrum the shear spectral slope changes from white to +2 below a vertic... more ... In the Garrett–Munk spectrum the shear spectral slope changes from white to +2 below a vertical mode number j*. GM76 uses j* = 3. Levine et al. ... 1981; Gregg et al. 1993; Winkel 1998) and in the middle atmosphere (Smith et al. 1987; Fritts 1989; Allen and Vincent 1995). ...
Strong internal tide generated currents and rough topography lead to intense mixing at the bottom... more Strong internal tide generated currents and rough topography lead to intense mixing at the bottom and the sloping sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
Strong internal tide generated currents and rough topography lead to intense mixing at the bottom... more Strong internal tide generated currents and rough topography lead to intense mixing at the bottom and the sloping sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
The inertial subrange Kolmogorov constant for the Lagrangian velocity structure function C0 is re... more The inertial subrange Kolmogorov constant for the Lagrangian velocity structure function C0 is related to the inertial subrange constant for the Lagrangian acceleration spectrum β by C0=πβ. However, Rλ must be greater than about 105 for the inertial subrange of the structure function to be sufficiently wide to accurately determine C0, while values of Rλ greater than 102 are sufficient to determine β. Taking these Rλ limitations into account, the only two known high-quality independent measurements of C0 are 5.5 and 6.4.
Large-amplitude (100–200 m) nonlinear internal waves (NLIWs) were observed on the continental slo... more Large-amplitude (100–200 m) nonlinear internal waves (NLIWs) were observed on the continental slope in the northern South China Sea nearly diurnally during the spring tide. The evolution of one NLIW as it propagated up the continental slope is described. The NLIW arrived at the slope as a nearly steady-state solitary depression wave. As it propagated up the slope, the wave propagation speed C decreased dramatically from 2 to 1.3 m s−1, while the maximum along-wave current speed Umax remained constant at 2 m s−1. As Umax exceeded C, the NLIW reached its breaking limit and formed a subsurface trapped core with closed streamlines in the coordinate frame of the propagating wave. The trapped core consisted of two counter-rotating vortices feeding a jet within the core. It was highly turbulent with 10–50-m density overturnings caused by the vortices acting on the background stratification, with an estimated turbulent kinetic energy dissipation rate of O(10−4) W kg−1 and an eddy diffusivity of O(10−1) m2 s−1. The core mixed continually with the surrounding water and created a wake of mixed water, observed as an isopycnal salinity anomaly. As the trapped core formed, the NLIW became unsteady and dissipative and broke into a large primary wave and a smaller wave. Although shoaling alone can lead to wave fission, the authors hypothesize that the wave breaking and the trapped core evolution may further trigger the fission process. These processes of wave fission and dissipation continued so that the NLIW evolved from a single deep-water solitary wave as it approached the continental slope into a train of smaller waves on the Dongsha Plateau. Observed properties, including wave width, amplitude, and propagation speed, are reasonably predicted by a fully nonlinear steady-state internal wave model, with better agreement in the deeper water. The agreement of observed and modeled propagation speed is improved when a reasonable vertical profile of background current is included in the model.
Strong internal tide generated currents and rough canyon topography lead to intense mixing at the... more Strong internal tide generated currents and rough canyon topography lead to intense mixing at the bottom and the sidewalls of Monterey Submarine Canyon. Estimates of mixing were made from measurements with SWIMS3, a depth-cycling towed body, at eleven cross-canyon transects and two along canyon-transects in upper Monterey canyon (at thalweg depths 10^(-3) m^2/s) over the canyon bottom, ranging from 70 m thick during neap tide to 300 m thick during spring tide over topographic features. The regions of elevated mixing extend up the canyon sidewalls, diminishing in thickness and magnitude of mixing as the shelf is approached. These sidewall boundary layers generated by the internal tide may be important for sediment resuspension and other transport processes in the canyon.
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