# HG changeset patch # User paugier <pierre.augier@univ-grenoble-alpes.fr> # Date 1695053387 -7200 # Mon Sep 18 18:09:47 2023 +0200 # Node ID 88dba473f0604ca3ce97c727e8d71e74128759c7 # Parent ae3a19bc7a76766766d6994b3508cf9e8ec45d4c tmp after conf Nice diff --git a/2022strat_polo_proj/review0/rebut1.tex b/2022strat_polo_proj/review0/rebut1.tex --- a/2022strat_polo_proj/review0/rebut1.tex +++ b/2022strat_polo_proj/review0/rebut1.tex @@ -45,11 +45,18 @@ hyperdiffusion? } +We performed with Jason Reneuve an extensive study on dealiasing methods +(also with phase shifting). It is not yet published but a notable result is that ... TODO... + + \itemit{p.5: what is the motivation behind forcing low frequency waves only? Wouldn't it be better to increase the wave frequency to better satisfy the timescale separation required by WWT? } +TODO: add in the article + add added text here. (geophysical fluids (for example M2 waves) + temporal spectra) + + \itemit{ Why is hyperviscosity added to the regular viscosity? Is it just for regularisation purposes, but in that case, the simulations presented cannot be @@ -57,12 +64,28 @@ would they all blow up without it? } +TODO: add in the article + add added text here. + +- Most of the simulations are proper DNS with $\kmax\eta$ larger or close to one. For example (40, 20), $\kmax\eta = 0.99$ and 1.05. + +- Few simulations are not DNS, but they can be to some extend characterized with the standard Reynolds number. + +- Without hyperviscosity the simulations would not blow up. + +- Dataset which can be later improved... + + \itemit{ Shear modes are removed from all simulations, but how is this achieved exactly? Is it done via a spectrally localised damping term or simply put to zero at every time steps? } +TODO: add in the article + add added text here. + +Put to zeros at each time step. Conserves energy. Similar physically to vertical walls in a tank. + + \itemit{ It is mentionned that the forcing is not delta-correlated in time but that its correlation time is consistent with the dispersion relation of internal @@ -74,6 +97,18 @@ change something to the results presented here? } +TODO: describe better the forcing in the article + add added text here. + +- no proper stochastic process involve. Phase and amplitude of the forced wavenumbers random and changed in time ... + +- a bit of Python to compute time spectra of such process. + +- this aspect of the forcing will be discussed in a paper describing more globally the dataset. + +TODO: add the question on possible effect of harmonic forcing. We don't know. +Interesting open question that could be investigated in future studies. + + \itemit{ Figure 7: could you show the spatial structure of the dominant vortical mode by filtering the coefficients in Fourier space and transform it back to physical @@ -81,10 +116,16 @@ and without vortical modes, would be helpful in my opinion. } +Add a 3D figure... + + \itemit{ Figure 9: what is the purpose of the kz=kh line? } +? + + \itemit{ Figure 16: this is an important plot in my opinion, it might be useful to include other studies? In particular, it is rather suprising that [46] is so far @@ -93,12 +134,24 @@ filling the gap between these two extremes? } +TODO: which studies with wave forcing? Waite... Lindborg... ??? + +For studies motivated by geophysical flows, the focus is more on buoyancy Reynolds number large or at least not very small. + +Unfortunately, not always easy to correctly quantify these numbers from the data given in the articles. + + \itemit{ The shear modes are always suppressed while the vortical modes are either left or suppressed. Do the authors expect surprising behaviours with the shear modes but without the vortical modes? } +We know thanks to a study on 2D turbulence (Calpe-linares PhD thesis) +that shear modes can grow without toroidal modes. Therefore we can anticipate accumulation of energy in shear modes, +which should become very strong and distore the waves. + + \itemit{ Note that Le Reun et al. [46] did not have to remove neither shear nor vortical modes (while the same authors had to remove the geostrophic flow in @@ -110,9 +163,10 @@ grow if not directly forced? } +TODO: improve the discussion on the difference between Le Reun et al. + \end{enumerate} - \subsection*{Additional small comments:} \begin{itemize} diff --git a/2022strat_polo_proj/review0/rebut2.tex b/2022strat_polo_proj/review0/rebut2.tex --- a/2022strat_polo_proj/review0/rebut2.tex +++ b/2022strat_polo_proj/review0/rebut2.tex @@ -52,6 +52,9 @@ and why, and how $n_z$ is chosen. } +TODO: better describe in the method section. + + \itemit{ The poloidal forcing is meant to excite only waves but you do not discuss its impact on the potential vorticity (PV), which governs the vortical mode. In @@ -59,6 +62,14 @@ given how important a concept it is in geophysical fluid mechanics. } +PV is known to be much less dynamically important in stratified flows than in stratified and rotating flows. +The Ertel PV $\bomega \cdot \bnabla (N^2 z + b) = \omega_z (N^2 + \partial_z b) + \bomega_h \cdot \bnabla_h b$ +is not quadratic and is not equal to the Charney PV. +There is no PV cascade like in quasi-geostrophic flows. + +The forcing in poloidal velocity produces and removes PV but we do not know what can be deduced from that. + + \itemit{ I felt overwhelmed by the great number of non-dimensional parameters introduced here; even with all these definitions one could still invent more, ie @@ -69,17 +80,30 @@ unfolded. } +- Improve eq (17) + +- Move end of page 7 later... + +- No non-dimensional numbers based on hyper-viscosity ... + + \itemit{ You talk of “removing vortical modesâ€. How is that done numerically? Is it a similar process as in Holmes-Cerfon et al. in JFM 2013? } +TODO: improve the method section. + + \itemit{ In the discussion session you say that the energy conversion rate does not fluctuate around zero. As only the kinetic energy is forced, shouldn’t the KE->PE conversion rate be nonzero a priori? } +For Vincent... + + \end{enumerate} \subsection*{Minor comments} @@ -92,6 +116,7 @@ speeds, not scale separation as stated here. } + \itemit{ (3) maybe it could be stated how these are derived from each other? Also, the folklore in oceanography is that the internal wave energy flows downscale in @@ -99,6 +124,12 @@ that? } +- oceans: forced waves (inertial waves, M2 and spontaneous generation from vortices) $\omega/N$ small. + +- our results also transfers towards slow waves + +- open question in ocean and in WWT theories + \itemit{ typo p4 hyper viscosity }