NI discussion about internal_waves_barkley_canyon HOT 2 CLOSED

• Update outline, based on this Issue (and archived).
• Refocus write-up.
• Cut wordiness, focus on main points.
• Flat line for NI delay plot, and just one component.
  
• Check Alford (2012) for his plot, and perhaps vertical propagation speed.
• This is a bit involved, requiring plane wave fits to estimate frequency and wavenumber, and then c_gz (mean of 13 m/day).
• Get dispersion relation for vertical propagation (why low modes more horizontal?) in k_z (a.k.a. m) and omega.
• D'Asaro et al. (1995) do a good job describing this phenomenon. The divergence forced inertial pumping at the ML base causes oscillating pressure gradients in the thermocline and accelerates inertial currents at depth. The rate of vertical energy transfer depends on the horizontal scale of the ML inertial currents, with smaller horizontal scale ML currents propagating vertical energy faster. As vertical modes have progressively slower horizontal group velocities, the low modes propagate their energy away, first. As the low mode energy propagates away, the available energy and horizontal scale of the ML inertial currents decreases. Vertical energy propagation into the thermocline increases accordingly, with a notable maximum associated with a timescale of the departure of modes 1 and 2. Additionally, the beta effect also decreases the north-south horizontal wavenumber, l, with time, which in turn decreases the horizontal scale of the ML inertial currents. Observationally, a notable increase in vertical propagation occurs around 8-10 days after D'Asaro's recorded storm.
  
  where alpha^2 = k^2 + l^2
• Vertical dispersion relation (Alford 2012, 2013):
  
• Alford (2016) summarises NI vertical propagation as 'neither the decay of mixed-layer motions nor the rate of energy transfer into the deep ocean can adequately be predicted for the best-documented storm response on record'. So it's difficult to say.

from internal_waves_barkley_canyon.

Added to write-up. Archived for reference.

from internal_waves_barkley_canyon.