DOI: 10.5061/dryad.v15dv424f
title: Boundary layer turbulence and abyssal recipes (BLT): Moored observations

description: These data were collected as part of the Boundary Layer Turbulence and
 Abyssal Recipes (BLT Recipes) Experiment which focused on near-bottom
 processes within a continental slope canyon on the eastern side of the
 Rockall Trough, off Ireland. This specific dataset contains moored
 observations from various sites within the canyon.
description: Data were collected on subsurface oceanographic moorings. See the
 README for a detailed description of mooring instrumentation and
 locations.
description: # Boundary Layer Turbulence and Abyssal Recipes (BLT): Moored Observations
 [https://doi.org/10.5061/dryad.v15dv424f](https://doi.org/10.5061/dryad.v15dv424f) Corresponding author: Gunnar Voet, [gvoet@ucsd.edu](mailto:gvoet@ucsd.edu) ## Overview These data were collected as part of the Boundary Layer Turbulence and Abyssal Recipes (BLT Recipes) Experiment which focused on near-bottom processes within a continental slope canyon on the eastern side of the Rockall Trough, off Ireland. This specific dataset contains moored observations from various sites within the canyon. Data collection was funded through NSF award [OCE-1756264](https://www.nsf.gov/awardsearch/showAward?AWD_ID=1756264). Short-term mooring June/July 2021: * **MP1**: A McLane Moored Profiler was deployed for one week in July 2021 and was outfitted with a Seabird SBE52 CTD, a Falmouth Scientific Inc. acoustic current meter, a Turner C-FLUOR fluorometer and two fast-sampling thermistor probes. The mooring had a downward-looking RDI Longranger 75 kHz Acoustic Doppler Current Profiler (ADCP) mounted in the top float. Mooring July 2021 - August 2022: * **TCHAIN**: A [NIOZ](https://www.nioz.nl) thermistor chain with a downward-looking RDI Longranger 75 kHz ADCP mounted in the top float. Only ADCP data are archived here for this mooring, for thermistor data contact Hans van Haren at NIOZ. Moorings July 2021 - October 2021: * **MP2**: Profiling mooring MP1 was re-deployed, without the fluorometer and fast-sampling thermistor probes mounted on the McLane Moored Profiler, in July 2021. MP2 was recovered in October 2021. * **MAVS1 & MAVS2**: Two moorings, which consisted of ~80 Seabird SBE56/RBR Solo thermistors, one to two SBE37 microcats, and 8 Modular Acoustic Velocimeters (MAVS), were deployed in July 2021. Both moorings also had one downward-looking RDI Longranger 75 kHz ADCP mounted in the top float. MAVS1 and MAVS2 were recovered in October 2021. Modular Acoustic Velocimeter data will be published elsewhere. Moorings October 2021 - August 2022: * **MP3**: Mooring MP2 was re-deployed without any technical changes as and redeployed in a cross-canyon configuration. During the third cruise in August 2022, another 6 microstructure stations were conducted with the epsi-fish profiler and all moorings were recovered. MP3 was recovered in August 2022. * **MAVS3 & MAVS4**: Moorings MAVS1 and MAVS2 wered re-deployed with only minimal changes in October 2021 as MAVS3 and MAVS4. MAVS3 and MAVS4 were recovered in August 2022. Modular Acoustic Velocimeter data will be published elsewhere. Short-term mooring August 2022: * **G1**: An upward-looking RDI Longranger 75 kHz ADCP was deployed near the seafloor for about 5 days in August 2022. ## Description of the data and file structure The dataset contains data files derived from RDI Longranger 75 kHz ADCPs, Seabird SBE37 CTDs, McLane Moored Profilers, and thermistors (a mixture of RBR Solo and Seabird SBE56). A file with mooring locations and bottom depths (based on multibeam bathymetry) is provided in addition. ### Mooring location File: `mooring_locations.nc` Structure: ``` Dimensions: (mooring) Coordinates: * mooring (mooring) _adcp.nc` Structure: ``` Dimensions: (depth, time) Coordinates: * depth (depth) float64 ... : depth [m] * time (time) datetime64[ns] ... : time Data variables: pg (depth, time) float64 ... : percent good per average u (depth, time) float32 ... : eastward velocity [m/s] v (depth, time) float32 ... : northward velocity [m/s] w (depth, time) float32 ... : vertical velocity [m/s] e (depth, time) float32 ... : error velocity [m/s] u_std (depth, time) float32 ... : u standard deviation per average [m/s] v_std (depth, time) float32 ... : v standard deviation per average [m/s] w_std (depth, time) float32 ... : w standard deviation per average [m/s] e_std (depth, time) float32 ... : e standard deviation per average [m/s] amp (depth, time) float32 ... : backscatter amplitude [db] temperature (time) float32 ... : ADCP temperature [°C] pressure (time) float32 ... : ADCP pressure [dbar] pressure_std (time) float32 ... : ADCP pressure standard deviation per average [dbar] pressure_max (time) float32 ... : ADCP pressure maximum per average [dbar] npings (time) int16 ... : number of pings in average xducer_depth (time) float64 ... : transducer depth from pressure [m] ``` ### SBE37 Files: `_sbe37_sn.nc` Structure: ``` Dimensions: (time) Coordinates: * time (time) datetime64[ns] ... : time Data variables: p (time) float64 ... : pressure [dbar] t (time) float64 ... : in-situ temperature [°C] c (time) float64 ... : conductivity [ms/cm] SP (time) float64 ... : practical salinity SA (time) float64 ... : absolute salinity [kg/m^3] CT (time) float64 ... : conservative temperature [°C] sg0 (time) float64 ... : potential density [kg/m^3] ``` ### MP Files: `_mp.nc` Structure: ``` Dimensions: (time, z) Coordinates: p (z) uint16 ... : pressure [dbar] * z (z) float64 ... : depth [m] * time (time) datetime64[ns]... : time profile (time) float64 ... : profile number hab (z) float64 ... : height above bottom [m] time2 (z, time) datetime64[ns] ... : 2D time Data variables: datenum (time) float64 ... : Matlab time yday (time) float64 ... : year day year (time) float64 ... : year t (z, time) float64 ... : in-situ temperature [°C] th (z, time) float64 ... : potential temperature [°C] c (z, time) float64 ... : conductivity [mS/cm] sgth (z, time) float64 ... : potential density [kg/m^3] s (z, time) float64 ... : practical salinity u (z, time) float64 ... : eastward velocity [m/s] v (z, time) float64 ... : northward velocity [m/s] w (z, time) float64 ... : vertical velocity [m/s] pitch (z, time) float64 ... : pitch roll (z, time) float64 ... : roll dpdtave (z, time) float64 ... : profiling speed eps (z, time) float64 ... : dissipation of turbulent kinetic energy based on density inversions [W/kg] eps_t (z, time) float64 ... : dissipation of turbulent kinetic energy based on temperature inversions [W/kg] SA (z, time) float64 ... : absolute salinity [kg/m^3] CT (z, time) float64 ... : conservative temperature [°C] P (z, time) uint16 ... : 2D pressure N2 (z, time) float64 ... : buoyancy frequency [1/s] ``` Additionally, for **MP1**: Files: `mp1_chi.nc` Structure: ``` Dimensions: (time, z) Coordinates: * time (time) datetime64[ns] ... : time * z (z) float64 ... : depth [m] hab (z) float64 ... : height above bottom [m] Data variables: chi2 (z, time) float64 ... dissipation of thermal variance [K^2/s] ``` ### Gridded thermistor data Files: `_gridded_temperature.ta.gz` The tar archives contain netcdf files with 2-day gridded temperature per file. Structure: ``` Dimensions: (depth, time) Coordinates: * depth (depth) float64 ... : depth [m] sn (depth) int64 ... : thermistor serial number * time (time) datetime64[ns] ... : time sensor_type (depth)