Near-inertial shear and kinetic energy in the North Atlantic experiment (NISKINe): Moored observations
Data files
Sep 08, 2025 version files 26.85 GB
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auxiliary.tar.gz
81.59 MB
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gridded.tar.gz
506.19 MB
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M1_RBRSolo_proc.tar.gz
6.45 GB
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M1_RBRSolo_raw.tar.gz
16 GB
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M1.tar.gz
2.17 GB
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M2.tar.gz
1.44 GB
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M3.tar.gz
207.44 MB
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niskine_mooring_locations.nc
10.75 KB
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README.md
8.54 KB
Abstract
An 18-month deployment of moored sensors in Iceland Basin allows characterization of near-inertial (frequencies near the Coriolis frequency f with periods of ~14 h) internal gravity wave generation and propagation in a region with an active mesoscale eddy field and strong seasonal wind and heat forcing. The seasonal cycle in surface forcing deepens the mixed layer in winter and controls excitation of near-inertial energy. The mesoscale eddy field modulates near-inertial wave temporal, horizontal, and vertical scales, as well as propagation out of the surface layer into the deep permanent pycnocline. Wind-forced near-inertial energy has the most active downward propagation within anticyclonic eddies. As oceanic surface and bottom boundaries act to naturally confine the propagation of internal waves, the vertical distribution of these waves can be decomposed into a set of “standing” vertical modes that each propagate horizontally at different speeds. The lowest modes, which propagate quickly away from their generation sites, are most enhanced when the mixed layer is deep and are generally directed southward.
https://doi.org/10.5061/dryad.g1jwstr3w
Corresponding author:
Gunnar Voet, gvoet@ucsd.edu
Overview
These data were collected as part of the Near-Inertial Shear and Kinetic Energy experiment (NISKINe), which focused on the generation, propagation, and dissipation of near-inertial waves in the Iceland Basin. This specific dataset contains moored observations recorded in the center of Iceland Basin from May 2019 through October 2020.
Data collection was funded through ONR awards N00014-18-1-2423 and N00014-22-1-2182.
Three close-to-full-depth subsurface moorings were deployed in the Iceland Basin. The moorings were deployed for 18 months, from May 5, 2019, until October 5, 2020, in a triangular array separated by 15 km and centered around 59°6'N, 21°12'W in approximately 2,800 meters of water depth. The primary mooring, M1, was equipped with acoustic Doppler current Profilers (ADCPs), Sea-Bird SBE 37 CTDs, SBE 56 and RBR Solo thermistors, and turbulence-measuring χ-pods. Two additional moorings (M2 and M3) were equipped only with ADCPs.
Description of the data and file structure
Data files for individual instruments
Archives M1.tar.gz, M2.tar.gz, and M3.tar.gz contain compressed directory structures with raw and processed data from ADCPs, SBE37s, and SBE56s for each mooring. Additional RBR Solo temperature time series from mooring M1 are contained in separate archives (due to their large file sizes) in M1_RBRSolo_raw.tar.gz and M1_RBRSolo_proc.tar.gz. Raw data files are specific to instrument vendors. All processed data are stored in netCDF format. Variables in processed netCDF files are described below for different instrument types.
ADCP
ADCP data were processed using https://github.com/modscripps/velosearaptor.
Structure:
Dimensions: (z, time)
Coordinates:
* time (time)
* z (z) float64 ... : depth [m]
Data variables: (12/15)
pg (z, time) int8 ... : percent good per ensemble mean
u (z, time) float32 ... : ensemble-mean eastward velocity [m/s]
v (z, time) float32 ... : ensemble-mean northward velocity [m/s]
w (z, time) float32 ... : ensemble-mean vertical velocity [m/s]
e (z, time) float32 ... : ensemble-mean error velocity [m/s]
u_std (z, time) float32 ... : eastward velocity ensemble-mean standard deviation [m/s]
v_std (z, time) float32 ... : northward velocity ensemble-mean standard deviation [m/s]
w_std (z, time) float32 ... : vertical velocity ensemble-mean standard deviation [m/s]
amp (z, time) float32 ... : ensemble-mean backscatter amplitude
temperature (z, time) float32 ... : ensemble-mean temperature [°C]
pressure (z, time) float32 ... : ensemble-mean pressure [dbar]
pressure_max (z, time) float32 ... : maximum pressure per ensemble mean [dbar]
npings (z, time) float32 ... : number of pings in ensemble mean
SBE37
Seabird SBE37 data were processed using https://github.com/gunnarvoet/sbemoored.
Structure:
Dimensions: (time)
Coordinates:
* time (time)
Data variables:
p (time) float64 ... : pressure [dbar]
t (time) float64 ... : temperature [°C]
c (time) float64 ... : conductivity [mS/cm]
SP (time) float64 ... : practical salinity [psu]
SA (time) float64 ... : absolute salinity [g/kg]
CT (time) float64 ... : conservative temperature [°C]
sg0 (time) float64 ... : potential density referenced to 0 dbar minus 1000 [kg/m^3]
SBE56
Seabird SBE56 data were processed using https://github.com/gunnarvoet/sbemoored.
Structure:
Dimensions: (time)
Coordinates:
* time (time)
Data variables:
t (time) float64 ... : temperature [°C]
RBR Solo
RBR Solo data were processed using https://github.com/gunnarvoet/rbrmoored.
Structure:
Dimensions: (time)
Coordinates:
* time (time)
Data variables:
t (time) float64 ... : temperature [°C]
Gridded products
The archive gridded.tar.gzContains depth-gridded velocity and temperature fields combining data from several instruments on each mooring. Files marked as may2019containing data from instruments that failed after just about two weeks. Note that after instrument failure, only one working ADCP was left on mooring M3; there is no gridded velocity product for the full time series for this mooring. The file ADCP/proc/SN15694/M3_15694.nc in the archive M3 contains the full depth-gridded velocity record for the full 18-month record of this mooring.
Gridded temperature
Structure:
Dimensions: (depth, time)
Coordinates:
* depth (depth) ... : depth [m]
* time (time)
Data variables:
t (depth, time) float64 ... : temperature [°C]
Gridded velocity
Structure:
Dimensions: (z, time, adcp)
Coordinates:
* time (time)
* z (z) int64 ... : depth [m]
* adcp (adcp) int64 ... : ADCP serial number
Data variables:
u (z, time) float64 ... : eastward velocity [m/s]
v (z, time) float64 ... : northward velocity [m/s]
xducer_depth (adcp, time) float64 ... : ADCP transducer depth [m]
temperature (adcp, time) float64 ... : ADCP temperature [°C]
Auxiliary data
The The archivee contains mooring schematics, clock drift information, and processed multibeam data for the bathymetry in the vicinity of the mooring array.
Directory structure:
aux
├── bathymetry
│ └── merged_100_-28_-21_56_61.nc
├── clock_drift
│ ├── ADCP_time_offsets.txt
│ ├── ADCP_time_offsets2.txt
│ ├── RBRSolo_time_offsets.txt
│ ├── sbe37_time_offsets.txt
│ └── SBE56_time_offsets.txt
├── magnetic_declination.txt
└── mooring_layouts
├── NISKIN_M1_final.pdf
├── NISKIN_M1_final.svg
├── NISKIN_M2_final.pdf
├── NISKIN_M2_final.svg
├── NISKIN_M3_final.pdf
├── NISKIN_M3_final.svg
├── niskine_M1_sensor_config.csv
└── niskine_M1_sensor_config.pdf
Bathymetry
Gridded multibeam product with ocean depth in m.
File: aux/bathymetry/merged_100_-28_-21_56_61.nc
Structure:
Dimensions: (lat: 2916, lon: 4082)
Coordinates:
* lat (lat) float64 ... latitude
* lon (lon) float64 ... longitude
Magnetic declination
File: aux/magnetic_declination.txt
The file contains the magnetic declination (difference to true north) at the location and time of the moorings.
Mooring layouts
The directory aux/mooring_layouts/ contains mooring diagrams for each of the moorings in .pdf and .svg formats.
Additional information on sensor placement on mooring M1 is listed in aux/mooring_layouts/niskine_M1_sensor_config.csv. The PDF version of this file is a simple printout of the table with some color highlighting, but it contains the same information as the .csv file.
Clock drifts
Text files in the aux/clock_drift/ directory contains listings of sensor clock offsets after mooring recovery. These have been corrected for in the processed data.
Mooring locations
File: niskine_mooring_locations.nc
Structure:
Dimensions: (mooring: 3)
Coordinates:
* mooring (mooring) int64 24B 1 2 3
Data variables:
lon_planned (mooring) float64 ... : planned longitude
lat_planned (mooring) float64 ... : planned latitude
lon_actual (mooring) float64 ... : actual longitude from trilateration
lat_actual (mooring) float64 ... : actual latitude from trilateration
offset (mooring) float64 ... : offset from planned location [m]
depth_planned (mooring) int64 ... : depth at planned location [m]
depth_actual (mooring) int32 ... : depth at actual location [m]
Code/Software
Data processing code is at https://github.com/gunnarvoet/niskine-proc.
These data were collected as part of the Near-Inertial Shear and Kinetic Energy experiment (NISKINe), which focused on the generation, propagation, and dissipation of near-inertial waves in the Iceland Basin. This specific dataset contains moored observations recorded in the center of Iceland Basin from May 2019 through October 2020. Data were collected on subsurface oceanographic moorings.