Julia C. Muchowski, Christian Stranne, Martin Jakobsson, Lars Arneborg, Lars Umlauf, Peter Holtermann
This dataset contains broadband acoustic midwater data, ship acoustic doppler current profiler (ADCP) data, and in situ microstructure profiler (MSS) data from the Åland Sea, Baltic Sea. The dataset was collected with research vessel R/V Electra af Askö in 2020 and was used with a focus on turbulence measurements.
The acoustic data were collected with a hull-mounted broadband Simrad EK80 sonar (70 kHz center frequency). Midwater echo sounders permit remote observations of turbulence microstructure, but also more generally changes in the water column, its stratification and suspended particles, as well as individual fish, fish schools, and zooplankton. Ship ADCP data were collected with a hull-mounted 600 kHz Teledyne RDI Workhorse ADCP.
The co-located in situ data were collected with a free-falling microstructure profiler (MSS) and include high-resolution oceanographic data from two shear probes (from which energy dissipation rates are inferred), two fast FP07 thermistors as well as conductivity and depth data.
Marine Hydrography Midwater Acoustic Broadband Stratified turbulent mixing Simrad EK80 Microstructure profiler Åland Sea Baltic Sea
You can download all files automatically using the software wget and the following single command.
wget -i https://bolin.su.se/data/data/muchowski-2023-midwater-2020-1.txt
You may need to download the software wget.
The command uses wget to download all files specified in a file list. A list of all files is available at https://bolin.su.se/data/data/muchowski-2023-midwater-2020-1.txt
Because of the large data volume (62 GiB, 109 files), downloading all files can take can take long time and requires sufficent disk space on your system.
To download a selected subset, you can edit the file list and run wget with your revised list. Alternatively, you can select files for download in the file list below.
Click on the categories below to view the files. Click on the file links to download each file.
Julia C. Muchowski, Christian Stranne, Martin Jakobsson, Lars Arneborg, Lars Umlauf, Peter Holtermann (2023) Acoustic and in-situ observations of stratified turbulent mixing over rough bathymetry, Baltic Sea, March 2020. Dataset version 1. Bolin Centre Database. https://doi.org/10.17043/muchowski-2023-midwater-2020-1
Muchowski JC, Arneborg L, Umlauf L, Holtermann PL, Eisbrenner E, Humborg C, Jakobsson M, Stranne C (2022) Diapycnal Mixing Induced by Rough Small-Scale Bathymetry. Geophysical Research Letters (in review).
The data are provided in folders
MSS, named after the instruments. We include the collected raw data in the sub-folder
raw.zip and therefrom derived processed data in the folder
processed. Processed data are provided in the form of MATLAB mat structures.
The location of where the data was collected can be seen in the article by Muchowski et al. (their Figure 1).
ADCP raw data files have the prefix
ADCP and a running number in their file name. Several file extensions are included as outputted by the instrument manufacturer software Teledyne RDI VmDas:
.ENR: raw current velocity (ADCP) data, current velocity data in beam coordinates.
.ENS: .ENR data with navigational data from NMEA, current velocity data in beam coordinates.
.ENX: content of .ENS files transformed from beam to earth coordinates using NMEA heading, pitch, roll, as well as bin-mapped, screened for error velocity, and false targets.
.STA: short time average.
.LTA: provide long time average.
.N1R: .NMS ASCII NMEA files.
.VMO: option settings for collecting the ADCP data.
.LOG: text file with instrument log, including beam width, beam direction, and time stamps.
NMEA data is fed from the positioning system on the ship into the ADCP raw files and provides the real time coordinates of the vessel.
.LTA files can be read and displayed using the WinADCP software. Detailed information can be found in the VmDas User's guide.
EK80 raw data files have the date and time of the measurement as their filename in the form
Dyyyymmdd-Thhmmss. Note that the time stamp in the file name comes from computer time on the data acquisition PC and may differ from the GPS time stored in the actual raw data. EK80 raw data consist of the following file types:
.raw: measurement data
.idx: index files
.XYZ: files that contain longitude, latitude, depth, and time. The .XYZ files have the following additional information about the transducer in their filename:
NMEA data is fed from the positioning system on the ship into the EK80 raw files and provides the real time coordinates of the vessel.
In the EK80 data folder, we also included a subfolder for raw data of the calibration of the echosounder in the folder
calibration_data, including the EK80 raw data (subfolder
EK80-raw) as well as raw and preliminary processed CTD data (subfolder
EK80 raw files can be opened and visualized with e.g. the instrument manufacturer Simrad EK80 software as well as the python based ESP3 software (open source), and Echoview (commercial).
MSS raw data files have the prefix
E20 and a running number in their file name. File extension is
.MRD. File format is according to SSDA Sea & Sun Technology's Standard Data Acquisition software package rev. 228 28.06.2018.
Processed data are provided in the form of MATLAB
.mat structures with main content listed below. The matlab structures also include other varables than those listed here.
The ADCP Matlab structure includes only data that were collected on a subset of the data, used in the study by Muchowski et al. The filename includes additional information about the cruise (EL20), the ADCP hardware (600kHz), the temporal average of processed velocity data (30s), the used reference velocity (refNone). Data variables include:
Processed EK80 data files are named according to their general ID (
transect_##) for all transects during the cruise, their region and transect number (
SRUL#), followed by the start and end time of the measurement in the form
As an example: transect_27_SRUL7_T164506_T171505
Data variables include:
Processed MSS data files are named according to the date, start, and end time when they were collected (
yyyymmdd_hhmm_hhmm) and their station number (
Each Matlab structure has four components:
MSS.STA: station information, including
MSS.DATA: raw data from raw data file, including
MSS.CTD: 0.1 m resolution data, including:
MSS.MIX: 0.5 m resolution data, including:
The following table links transects (T1 – T6) that are analyzed in the study by Muchowski et al. to the microstructure (MSS ) profiles that were collected during those transects. Each transect has a number that is related to the total number of transects during the cruise (T21 – T27) and a number that only takes into account transects within a sub-region (with acronym SRUL) of the study area (T1 – T7). All data were collected during R/V Electra cruise EL20-IGV01 in 2020.
|General ID||MSS Profile||Transect name / transect number||Date_Start_End (UTC)|
|T21||76 – 81||SRUL1 / T1||20200302_1440_1536|
|T22||82 – 88||SRUL2 / T2||20200303_0903_1004|
|T23||89 – 101||SRUL3 / T3||20200303_1032_1151|
|T24||102 – 113||SRUL4 / T4||20200303_1225_1338|
|T25||114 – 116||SRUL5 / T5||20200303_1347_1447|
|T26||117 – 122||SRUL6 / T6||20200303_1511_1600|
|T27||123 – 125||SRUL7 / T7||20200303_1649_1710|
Department of Geological Sciences
SE-106 91 Stockholm
Earth science > Oceans > Ocean acoustics
Ocean > Atlantic Ocean > North Atlantic Ocean > Baltic Sea
Swedish Research Council (VR) 2018-04350 (Christian Stranne), German Research Foundation (DFG) HO 5891/1-1 (Peter Ludwig Holtermann), Leibniz Association (Germany) K227/2019 (Lars Umlauf, Peter Ludwig Holtermann), Baltic Sea Center (Christian Stranne, Julia Christin Muchowski), Stockholm University's strategic funds for Baltic Sea research (Christian Stranne).
Bolin Centre Database