Rick and Steve notes about internal_waves_barkley_canyon HOT 5 CLOSED

Read about these issues, develop questions, and then schedule a meeting in January.

from internal_waves_barkley_canyon.

Hi everyone,

I hope your holidays were cheerful, despite the circumstances.

Your feedback has been very useful for developing my analysis goals. I'd like to have our next meeting at the end of this month to discuss some questions I have (see below), and perhaps narrow things down to a feasible amount of content for my MSc thesis. It would be good to settle on a concrete set of goals I can work towards. For the meeting, I propose 10 am on Tuesday (26th), Wednesday (27th), or Friday (29th); please let me know if any of these will work. I'm looking forward to seeing you (digitally, at least), again!

From Rick's feedback:

• Baroclinic diurnal shelf waves: As they originate at the Juan de Fuca Strait and propagate NW along the coast, will these only be visible in Upper Slope (shelf) ADCP data, or will there also be evidence in the deeper Axis data? What are the most telling indicators of these baroclinic K1 shelf waves, besides propagation direction, to distinguish them from other incident baroclinic K1 tides (e.g. locally generated)?
• Blue-shifted near-inertial motions: The near-inertial peak in almost every PSD case is slightly higher in frequency than the expected f peak. How do you concretely determine whether this near-inertial peak is just a blue-shifted f peak, or is it just assumed?
• Internal solibores: The Axis ADCP is upward facing, and I've been using data beginning at ~50 m above bottom to eliminate the need to deal with some data quality issues closer to the bottom (though I will recheck if these data quality issues are consistently present). Furthermore, the two Axis instruments are 75 and 55 kHz, versus the 600 kHz model you use. Would the detection of internal solibores be feasible with this ADCP?
• Your 90s data would be very useful for interpreting and comparing seasonal trends, including those in the M2 and fM2 bands, if there is time!

From Steve's feedback:

• Critical slope: When determining source areas, for which instruments would the critical slope analysis be relevant? With the Axis ADCP being far within the twisting canyon, is it only the Upper Slope ADCP that would be useful to pick up scattering/reflection signals? Otherwise, a slope map and criticality analysis would be a great addition, if there is time.
• Rotary spectra: Is it enough to tighten up my spectral averaging, or would a finer temporal resolution for the data (currently using 15-minute bins) make a difference? The current spectral averaging is to help me identify prominent constituents and figure out the general story, so would your suggestion be most useful once I've identified some features I want to 'zoom in' on? I am also working on figuring out the noise floor of the instruments.

For Jody:

• How do you best distinguish baroclinic and barotropic tides in velocity data? Is it enough to remove the mean, as it's the primary variable in the barotropic/baroclinic energy consistency relation? Or is there some sort of filtering process that I'm missing in my reading (Rick & Steve mention a 'least squares method' to remove the 10 largest barotropic tidal constituents)?

Cheers,

Kurtis

from internal_waves_barkley_canyon.

@jklymak

I want to (and I believe, am supposed to) have our next committee meeting later this month. After some holiday reading based on the proposal feedback from Rick and Steve, I'd like to send them this email (above). Is there anything too obvious about some of my questions that I may have missed, or suggestions you may have? We can discuss during the meeting tomorrow, or later if there isn't enough time. Thanks!

from internal_waves_barkley_canyon.

Email sent to the committee addressing their suggestions and requesting a mid-February meeting.

from internal_waves_barkley_canyon.

Hi everyone,

I hope your holidays were cheerful, despite the circumstances!

Your feedback has been very useful for progressing with my analysis. To discuss my updated proposed goals (see below), I'd like to have our next meeting mid-February. For the time, I propose 10 am on Tuesday (23rd), Wednesday (24th), or Friday (26th); please let me know if any of these will work, or if you have alternative suggestions. I'm looking forward to seeing you, again (digitally, at least)!

In addition to the goals that were listed in the Proposal, I plan to address your feedback (with a few questions, perhaps!) by:

• Seeking a baroclinic diurnal signal that could indicate the presence of shelf waves propagating across Barkley Canyon from the Juan de Fuca.
• Evaluating expected versus observed frequency peaks to identify blue-shifted near-inertial motions.
• Looking for high-frequency whitening that could indicate internal solibores. Confirming their presence may be difficult, as the Axis ADCP is upward facing and data below ~50 m above bottom show some data quality issues (I will recheck if these issues are persistent).
• The 90's data would be very useful for interpreting and comparing seasonal trends, including those in the M2 and fM2 bands, though I feel this addition may only be feasible if there is enough time.
• A slope map and statement of critical slope angle for primary constituents is an essential addition. Further analysis may be time dependent, as with the 90's data.
• The current spectral averaging for rotary spectra is broad to help me identify prominent constituents and figure out a general story, and I'll certainly be using a finer resolution to tease out more information, going forward.
• Getting the noise floor of the ADCP is high on my To Do list, to determine if the spectrum flattening is physical or instrument restricted.

I'm excited to nail down the analysis and continue writing. And as we get closer to the final stretch, please keep me in mind if you see any fairly 'hands-on' job opportunities for the future; I doubt I will have the chance to participate in any cruises or fieldwork, so I'll just have to go for it!

from internal_waves_barkley_canyon.