Temperature timeseries and idealized simulations of internal solitary waves colliding with the Grande-Anse wharf, Saguenay Fjord, Canada
Data files
Feb 28, 2025 version files 6.63 GB
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Dryad_JA_Sci_Rep.zip
6.63 GB
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README.md
2.27 KB
Abstract
In 2019, the Motor Vessel Jaeger Arrow collided with the Grande-Anse Terminal wharf (Saguenay Fjord, Canada) during docking from unknown causes. However, the timeline of the incident and the ship's behavior during docking suggest that underwater waves may have caused the collision. Data collected in 2023 using a camera and thermometers confirmed that this area of the fjord regularly experiences underwater waves with wavelengths ranging from 50 to 100 m, wave heights of 1 and 3 m, and periods of around 2 min. These waves frequently collide with and reflect off the wharf, generating currents of 0.1 to 0.3 m s-1. Numerical simulations further illustrate the interactions between the waves and the wharf, highlighting regions near the wharf where wave-induced currents, both inshore and offshore, occur, including areas with near-zero currents that could create a false sense of calm conditions. Importantly, our observations also revealed that large ships, such as the Jaeger Arrow, can generate their own underwater waves, potentially compromising docking operations. While we cannot definitively confirm that underwater waves caused the incident involving the Jaeger Arrow, our study offers a plausible explanation: the ship may have been caught in a wavetrain reflecting off the wharf, leading to unpredictable movement during docking. These results highlight the potential risks posed by underwater waves to ship safety and maneuverability during docking operations, a topic under-explored in existing scientific literature.
https://doi.org/10.5061/dryad.ksn02v7fz
Description of the data and file structure
This dataset contains:
1) The CTD_data directory which contains two CTD profiles taken in the vicinity of the Grande-Anse Terminal.
This directory includes:
- CTD_far_field.mat: A MATLAB file containing depth (z) in meters and density (rho) in kg m⁻³ from CTD measurements at two stations:
- Station A (48° 25.40' N, 70° 51.94' W) – variables labeled with the suffix PMZA06.
- Station B (48° 24.81′ N, 70° 47.53′ W) – variables labeled with the suffix F14.
- read_CTD_mat.py: A Python script designed to read the data from CTD_far_field.mat.
2) The MITgcm_runs directory which contains three repositories with NetCDF outputs from 2D idealized simulations of four internal solitary waves colliding with the Grande-Anse Wharf in the Saguenay Fjord, Canada. The simulations differ by the value of the Available Potential Energy (APE) used to initialize the internal solitary waves with the DJL solver.
The three repositories are named APE1e4, APE1e5, and APE5e5, corresponding to the respective APE values. Each repository contains four NetCDF files:
- grid.glob.nc: Stores all grid variables.
- SurfDiag.APEXeX.nc: Contains snapshots of the surface height anomaly every 5 seconds.
- dynDiag.APEXeX.nc: Includes snapshots of the density anomaly and zonal and vertical mass-weighted velocities every 5 seconds.
- state.APEXeX.nc: Captures the instantaneous state of the model at the beginning, midpoint, and end of the simulation.
3) The RBR directory contains temperature and pressure time series for two events of internal solitary waves colliding with the Grande-Anse Wharf on September 20, 2023, and September 27, 2023.
This directory includes two NetCDF files, named after the event date:
- rbr_20230920.nc
- rbr_20230927.nc
Each file contains temperature and pressure time series as a function of depth, recorded at 48° 24.107′ N, 70° 50.001′ W during the respective internal wave events.
This dataset includes:
1) Temperature, salinity, and pressure measurements from CTD casts at two locations: (48° 25.40′ N, 70° 51.94′ W) and (48° 24.81′ N, 70° 47.53′ W).
2) NetCDF outputs from 2D idealized numerical simulations conducted using the MITgcm.
3) Temperature time series collected at 48° 24.107′ N, 70° 50.001′ W at various depths using 14 RBRsolo3 T temperature sensors and one RBRduet3 T.D temperature-depth sensor. The deepest instrument, positioned one meter above the seafloor, was the temperature-depth sensor. All time series are stored in a NetCDF file.