This repository contains codes and processed datasets for a manuscript entitled "Subtidal to supertidal variability of Reynolds stresses in a mid-latitude stratified inner-shelf", by A. Palóczy, J. A. MacKinnon and A. F. Waterhouse, published on the Journal of Physical Oceanography. This Jupyter notebook provides an overview of the contents.
The directory plot_figs/ contains the Python codes used to produce the figures in the manuscript (Figures 1-14). The codes depend on the data files in the data_reproduce_figs/ directory. Some of these are too large to be included in this repository, but are available for download from the links listed on the accompanying README files. Please contact André Palóczy if you have issues downloading the files.
We describe the spatio-temporal variability and vertical structure of turbulent Reynolds Stresses (RSs) in a stratified inner-shelf with an energetic internal wave climate. The RSs are estimated from direct measurements of velocity variance derived from bottom-mounted Acoustic Doppler Current Profilers. We link the RSs to different physical processes, namely internal bores, mid-water shear instabilities within vertical shear events related to wind-driven subtidal along-shelf currents; and non-turbulent stresses related to incoming Nonlinear Internal Wave (NLIW) trains. The typical RS magnitudes are O(0.01 Pa) for background conditions, with diurnal pulses of O(0.1-1 Pa), and O(1 Pa) for the NLIW stresses. A NLIW train is observed to produce a depth-averaged vertical stress divergence sufficient to accelerate water 20 cm/s in 1 hour, suggesting NLIWs may also be important contributors to the depth-averaged momentum budget. The subtidal stresses show significant periodic variability and are O(0.1 Pa). Conditionally-averaged velocity and RS profiles for northward/southward flow provide evidence for down-gradient turbulent momentum fluxes, but also indicate departures from this expected regime. Estimates of the terms in the depth-averaged momentum equation suggest that the vertical divergence of the RSs are important terms in both the cross-shelf and along-shelf directions, with geostrophy also present at leading-order in the cross-shelf momentum balance. Among other conclusions, the results highlight that internal bores and shoaling NLIWs may also be important dynamical players in other inner-shelves with energetic internal waves.
- André Palóczy (apaloczy@ucsd.edu)
- Jennifer A. MacKinnon(jmackinnon@ucsd.edu)
- Amy F. Waterhouse(awaterhouse@ucsd.edu)
The authors gratefully acknowledge funding from the Office of Naval Research (ONR), grants grants N00014-15-1-2885, N00014-15-1-2633 and N00014-5-1-2631. Input from two anonymous reviewers substantially improved the manuscript. Thanks to Stephen Monismith, Jack McSweeney, Johannes Becherer, Jim Lerczak and Anthony Kirincich for helpful discussions during the writing of this manuscript, and to Johanna Rosman for helpful discussions and assistance in implementing the Adaptive Filtering Method. We thank Pieter Smit and Tim Janssen of Sofar Technologies for providing the wave data, and Jim Thomson and Merrick Haller for providing the land-based meteorological data. Thanks also to Eric Terrill and the technical team at the Coastal Observing R&D Center at Scripps Institution of Oceanography for providing the marine meteorological observations (miniMET buoy). We also thank the Captain and crew of the R/V Sally Ride, Christian McDonald and Brett Pickering for successfully deploying and recovering the moorings used in this study.
Codes and reduced datasets required to reproduce the results are available at https://github.com/apaloczy/InnerShelfReynoldsStresses, archived under DOI 10.5281/zenodo.4601716. The full inner shelf dataset with the raw mooring data required to derive the reduced datasets is archived under DOI 10.6075/J0WD3Z3Q.