Details for MERGED_SLOW and MERGED_EPSI (follows after MERGED_SLOW below): >> ncdisp('MERGED_SLOW.nc') Source: C:\Users\ngfif\OneDrive - University of Bergen\work\Projects\ProVoLo\analysis_Gna_MR059_Sep17\Process_Submit\MERGED_SLOW.nc Format: netcdf4 Global Attributes: title = 'Dissipation measurements from a Slocum glider in the Lofoten Basin, September 2017' summary = 'Ocean microstructure measurements were obtained from a Rockland Scientific (RSI) MicroRider attached to an electric Slocum glider. Data were collected during the cruise KB2017618 onboard R.V. Kristine Bonnevie, as a part of the PROVOLO (Watermass transformation processes and vortex dynamics in the Lofoten Basin of the Norwegian Sea) project, funded by the Research Council of Norway (project number 250784). The glider mission started on 6 September 2017 outside of the Lofoten Vortex, a permanent anticyclonic eddy in the Lofoten Basin of the Norwegian Sea. The glider was then navigated into the core of the eddy until the mission ended on 12 September 2017. In addition to the turbulence package, the glider was equipped with an unpumped Seabird conductivity-temperature (CTD) sensor, a Wetlab ECO-puck (fluorescence and turbidity), and an Andreraa oxygen Optode. All instruments were configured to sample during dives and climbs of the glider. The dissipation rate was measured using two airfoil shear probes. Turbulence channels sampled at a rate of 512 per second, and the slow channels at 64 per second. The dataset has been processed and formatted in accordance with the SCOR Working Group ATOMIX guidelines and recommendations. This set of two NetCDF (NC) files are constructed by concatenating time series from the individual NC files per instrument's native file, which are provided separately (one file between consecutive surfacings of the glider, 106 files in total). MERGED_SLOW is the collection of time series from selected sensors including temperature, salinity, dissolved oxygen concentration, turbidity, chl-a fluorescence, as well as flight parameters, averaged in 1-second windows. MERGED_EPSI is the collection of time series of dissipation rate estimates together with quality control parameters. 212 sections from the 106 files are concatenated. A section is a continuous segment of the time series with dissipation estimates, for example separate sections from the dive and climb parts of the time series. The concatenated time series differ from the individual NC files as follows. When producing the merged files, only good data are used (i.e., quality flags are applied). Furthermore the practical salinity and temperature from the glider are corrected against shipboard measurements using constant offsets. Finally, 1-s salinity and density data are despiked and slighlty smoothed. Users interested in the dissipation profiles and 1-second time-averaged sensor data can use these files and avoid downloading the full records of the individual NC files. The MERGED_SLOW and MERGED_EPSI files are not gridded in time or pressure. Each data point has its own time stamp and a pressure value, with time increasing monotonically from the start of the first section. Sections where the glider ascends (climbs) will therefore have pressure values decreasing with time. For more detailed information, please refer to the comments within the data file.' platform = 'sub-surface glider' comment = 'Ocean microstructure measurements were obtained from a Rockland Scientific (RSI) MicroRider (MR) attached to an electric Slocum glider. Data were collected during the cruise KB2017618 onboard R.V. Kristine Bonnevie, as a part of the PROVOLO (Watermass transformation processes and vortex dynamics in the Lofoten Basin of the Norwegian Sea) project, funded by the Research Council of Norway (project number 250784). The glider mission started on 6 September 2017 outside of the Lofoten Vortex, a permanent anticyclonic eddy in the Lofoten Basin of the Norwegian Sea. The glider was then navigated into the core of the eddy until the mission ended on 12 September 2017. The glider Gnaa is a Teledyne Webb Research 1000m electric glider (Slocum G1, SN103). The glider was equipped with an upumped Seabird conductivity-temperature (SN 0069), a Wetlab ECO-puck (fluorescence and turbidity, FLNTU SN 771), an Andreraa oxygen Optode (3830, SN 903), and an integrated RSI MicroRider (MR-1000-LP, SN059) with two shear probes (S1=M833, oriented vertical; S2=M666 oriented horizontal) and two thermistors (T1=T864, T2=T996; both sensors malfunctioned) for measuring turbulence microstructure. Both the CTD and the MR were configured to sample during dives and climbs of the glider. The data from the MR include measurements from 2 shear probes, 2-axis piezo-accelerometers (vibration), an inclinometer (pitch and roll) and a pressure transducer. The pressure transducer was damaged and we rely on the pressure record from the glider's sensors. Data from both thermistors were of low quality and are not included in the files. Turbulence channels sampled at a rate of 512 per second, and the slow channels at 64 per second. The glider was operated with fixed battery positions during dives and climbs to reduce vibrations from the servo mode. Shallower dives prior to fixing the battery position are excluded from the data set. In total 106 files are processed, out of a total of 114, excluding the short files when the glider was on deck or at the surface. The 106 files resulted in 212 sections. A section (a more general term for a profile) is a continuous part of the time series that has been selected for dissipation estimates. As the glider moves through the water while collecting data, its flight characteristics may change and at times may not meet the conditions necessary for good dissipation estimates. This can result in multiple separated sections of dissipation estimates per dive or climb. Each such section has a unique section identifier number. The two NetCDF files described below are constructed from the 212 sections. Users interested in concatenated dissipation profiles and 1-second time-averaged sensor data can use these files and avoid downloading of full records from the individual NC files. MERGED_SLOW contains the data from selected sensors, along with flight parameters, averaged in 1-second windows, and then concatenated in a 1-D time series. MERGED_EPSI contains dissipation rate estimates together with quality control parameters concatenated in a 1-D time series. The processing of the data and the format of this data set follows the recommendations and guidelines of the SCOR Working Group 160, ATOMIX (https://atomix.app.uib.no/), as decribed in Lueck et al. (2024). The processing was based on the standard Matlab routines provided by Rockland Scientific, which were adjusted for the ATOMIX recommendations. The glider data are processed using the GEOMAR Matlab Slocum glider processing toolbox (Krahmann, 2023). Spectral calculation and dissipation rate estimate details are given in the attributes and processing parameters. Spectra are obtained using 2-s fft length. Dissipation estimates are obtained over 10 s segments, overlapping by 5 s (50% overlap), using the cleaned shear spectra using the Goodman method and the Lueck model spectrum. The short fft length is not ideal for resolving low dissipation rates, but was necessary to avoid the contamination at low wavenumbers from glider motion. The concatenated time series differ from the individual NC files as follows. 1) When producing the merged files, in addition to the automated quality assurance during the processing, we performed manual quality screening and updated the flag values. The screening removed data (i.e., replaced with NaN) during times with malfunctioning probes, contamination from altimeter effects, abrupt flight behavior changes, and when hotel data were not available. More details can be found in the description and attributes of the two merged NC files. Data quality flags for dissipation estimates are summarized in the attributes of the variable EPSI_FLAGS. In particular, we used a FOM threshold of 1.3. For dissipation estimates less than 1e-10 W/kg, we relaxed this threshold to a value of two, as this parameter is not well-constrained for low dissipation rates. We observed systematically larger FOM values with decreasing dissipation rates, most with marginally acceptable estimates. This choice was made to retain noise-level estimates instead of introducing gaps in the data. Users may want to apply additional quality screening. In the MERGED_EPSI file, quality flags are applied to EPSI_FINAL time series. A final dissipation estimate, EPSI_FINAL, failing the data quality control is reported as NaN; however, the individual dissipation estimates from each probe are accessible in the EPSI parameter. 2) The practical salinity and temperature from the glider are corrected against shipboard measurements using constant offsets of Toffset = -0.044C and Soffset = 0.0077 (in the form Scorrected = Smeasured + Soffset). Finally, 1-s salinity are de-spiked using a 5 point median filter and 2 standard deviations threshold. Potential density anomaly is re-calculated, similarly de-spiked and slightly smoothed using 11 point moving mean. The corrections, de-spiking and smoothing are not applied in the individual NC files. The data in the concatenated files are not gridded in time or pressure. Each data point has its own time stamp and a pressure value, with time increasing monotonically from the start of the first section. Sections when the glider ascends (climbs) will therefore have pressure values decreasing with time.' conventions = 'CF-1.6, ACDD-1.3, ATOMIX-1.0' history = 'Version 1' area = 'Norwegian Sea' geospatial_lat_min = 69.9 geospatial_lat_max = 70.3 geospatial_lon_min = 0.7 geospatial_lon_max = 2.6 geospatial_vertical_min = 0 geospatial_vertical_max = 311 geospatial_vertical_positive = 'down' time_coverage_start = '2017-09-06T17:00:37Z' time_coverage_end = '2017-09-12T04:22:52Z' creator_name = 'Fer, Ilker' creator_email = 'ilker.fer@uib.no' creator_url = 'https://www.uib.no/gfi' institution = 'Geophysical Institute, University of Bergen, Norway' authors = 'Fer, Ilker; Bosse, Anthony' project_name = 'PROVOLO' cruise = 'KB2017618' vessel = 'F.F. Kristine Bonnevie' principal_investigator = 'Fer, Ilker' contact = 'ilker.fer@uib.no' references = 'https://atomix.app.uib.no/; Lueck, R., I. Fer, C. E. Bluteau, M. Dengler, H. P., R. Inoue, A. LeBoyer, S.-A. Nicholson, K. Schulz, and C. Stevens (2024), Best practices recommendations for estimating dissipation rates from shear probes, Frontiers in Marine Science, 11, https://doi.org/10.3389/fmars.2024.1334327. Krahmann, Gerd (2023) GEOMAR FB1-PO Matlab Slocum glider processing toolbox. https://doi.org/10.3289/SW_4_2023.' acknowledgements = 'This data set is made possible by the funding from the Research Council of Norway' keywords = 'Norwegian Sea, Lofoten Basin, glider, mixing, turbulence, dissipation rate, microstructure, shear probes' source = 'sub-surface glider' license = 'http://creativecommons.org/licenses/by/4.0/' citation = 'Fer, Ilker and Anthony Bosse (2024), Dissipation measurements from a Slocum glider in the Lofoten Basin, September 2017. [Dataset] Norwegian Marine Data Centre, https://doi.org/10.21335/NMDC-1469977935' instrument = 'MicroRider-1000LP' instrument_serial_number = 59 instrument_sample_rate = 512 instrument_sampling_mode = 'continuous' profiling_direction = 'glide' time_reference_year = 0 creation_time = '2024-08-08T14:05:26Z' date_modified = '2024-08-08T14:05:26Z' date_created = '2024-08-08' Dimensions: TIME_DIM = 351296 Variables: TIME Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'time' units = 'Days since 0000-01-00T00:00:00Z' axis = 'T' long_name = 'Serial date number' calendar = 'proleptic_gregorian' comment = 'Standard MATLAB serial date number. It represents the fractional number of days from a fixed, preset date (January 0, 0000) in the proleptic ISO calendar. 1 January noon is day 1.5.' SECTION_NUMBER Size: 351296x1 Dimensions: TIME_DIM Datatype: int32 Attributes: standard_name = 'unique_identifier_for_each_section_of_data_from_timeseries' units = '1' long_name = 'A unique indentifier counter defining sections of the time series extracted for dissipation estimates' LON Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'longitude' units = 'degree_east' long_name = 'longitude' LAT Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'latitude' units = 'degree_north' long_name = 'latitude' FILE_NUM Size: 351296x1 Dimensions: TIME_DIM Datatype: int32 Attributes: standard_name = 'file_number' units = '1' long_name = 'file or cast number/counter of the native instrument file' PRES Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_pressure' units = 'decibar' long_name = 'Sea water pressure, equals 0 at sea-level' PSPD_REL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_speed_wrt_sea_water' units = 'm s-1' long_name = 'Platform speed with respect to sea water' PITCH Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_pitch_angle_fore_up' units = 'degree' long_name = 'Positive pitch represents thefront of the platform rising as viewed by an observer on top of the platform facing forward' PITCH_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_pitch_angle_fore_up' units = 'degree' long_name = 'Positive pitch represents thefront of the platform rising as viewed by an observer on top of the platform facing forward' comment = 'Measured by the sensor of the hotel (e.g., a glider)' ROLL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_roll_angle_starboard_down' units = 'degree' long_name = 'Positive roll represents the right side of the platform falling as viewed by an observer on top of the platform facing forward' ROLL_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_roll_angle_starboard_down' units = 'degree' long_name = 'Positive roll represents the right side of the platform falling as viewed by an observer on top of the platform facing forward' comment = 'Measured by the sensor of the hotel (e.g., a glider)' AOA Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_angle_of_attack' units = 'degree' long_name = 'Angle of attack, the angle between the glider principal axis and the glider path' TEMP_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_temperature' units = 'degree_Celsius' long_name = 'sea water temperature in-situ ITS-90 scale' comment = 'Measured by the sensor of the hotel (e.g., a glider)' PSAL_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_practical_salinity' units = '1' long_name = 'Sea water practical salinity' comment = 'Measured by the CTD sensor of the hotel (e.g., a glider)' SIG0_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_potential_density_anomaly' units = 'kg m-3' long_name = 'sea water temperature potential density anomaly referenced to surface pressure' comment = 'Measured by the CTD sensor of the hotel (e.g., a glider)' DOXY_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'moles_of_oxygen_per_unit_mass_in_sea_water' units = 'micromole kg-1' long_name = 'dissolved oxygen concentration in sea water (not calibrated)' comment = 'Measured by the optode of the hotel (e.g., a glider). Measurements are not calibrated against water samples.' CHLA_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'fluorescence' units = 'mg m-3' long_name = 'chlorophyll a fluorescence (not calibrated)' comment = 'Measured by the sensor of the hotel (e.g., a glider). Measurements are not calibrated against water samples.' TURBID_HOTEL Size: 351296x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_turbidity' units = 'NTU' long_name = 'sea water turbidity (not calibrated)' comment = 'Measured by the sensor of the hotel (e.g., a glider). Measurements are not calibrated against water samples.' >> >> ncdisp('MERGED_EPSI.nc') Source: C:\Users\ngfif\OneDrive - University of Bergen\work\Projects\ProVoLo\analysis_Gna_MR059_Sep17\Process_Submit\MERGED_EPSI.nc Format: netcdf4 Global Attributes: title = 'Dissipation measurements from a Slocum glider in the Lofoten Basin, September 2017' summary = 'Ocean microstructure measurements were obtained from a Rockland Scientific (RSI) MicroRider attached to an electric Slocum glider. Data were collected during the cruise KB2017618 onboard R.V. Kristine Bonnevie, as a part of the PROVOLO (Watermass transformation processes and vortex dynamics in the Lofoten Basin of the Norwegian Sea) project, funded by the Research Council of Norway (project number 250784). The glider mission started on 6 September 2017 outside of the Lofoten Vortex, a permanent anticyclonic eddy in the Lofoten Basin of the Norwegian Sea. The glider was then navigated into the core of the eddy until the mission ended on 12 September 2017. In addition to the turbulence package, the glider was equipped with an unpumped Seabird conductivity-temperature (CTD) sensor, a Wetlab ECO-puck (fluorescence and turbidity), and an Andreraa oxygen Optode. All instruments were configured to sample during dives and climbs of the glider. The dissipation rate was measured using two airfoil shear probes. Turbulence channels sampled at a rate of 512 per second, and the slow channels at 64 per second. The dataset has been processed and formatted in accordance with the SCOR Working Group ATOMIX guidelines and recommendations. This set of two NetCDF (NC) files are constructed by concatenating time series from the individual NC files per instrument's native file, which are provided separately (one file between consecutive surfacings of the glider, 106 files in total). MERGED_SLOW is the collection of time series from selected sensors including temperature, salinity, dissolved oxygen concentration, turbidity, chl-a fluorescence, as well as flight parameters, averaged in 1-second windows. MERGED_EPSI is the collection of time series of dissipation rate estimates together with quality control parameters. 212 sections from the 106 files are concatenated. A section is a continuous segment of the time series with dissipation estimates, for example separate sections from the dive and climb parts of the time series. The concatenated time series differ from the individual NC files as follows. When producing the merged files, only good data are used (i.e., quality flags are applied). Furthermore the practical salinity and temperature from the glider are corrected against shipboard measurements using constant offsets. Finally, 1-s salinity and density data are despiked and slighlty smoothed. Users interested in the dissipation profiles and 1-second time-averaged sensor data can use these files and avoid downloading the full records of the individual NC files. The MERGED_SLOW and MERGED_EPSI files are not gridded in time or pressure. Each data point has its own time stamp and a pressure value, with time increasing monotonically from the start of the first section. Sections where the glider ascends (climbs) will therefore have pressure values decreasing with time. For more detailed information, please refer to the comments within the data file.' platform = 'sub-surface glider' comment = 'Ocean microstructure measurements were obtained from a Rockland Scientific (RSI) MicroRider (MR) attached to an electric Slocum glider. Data were collected during the cruise KB2017618 onboard R.V. Kristine Bonnevie, as a part of the PROVOLO (Watermass transformation processes and vortex dynamics in the Lofoten Basin of the Norwegian Sea) project, funded by the Research Council of Norway (project number 250784). The glider mission started on 6 September 2017 outside of the Lofoten Vortex, a permanent anticyclonic eddy in the Lofoten Basin of the Norwegian Sea. The glider was then navigated into the core of the eddy until the mission ended on 12 September 2017. The glider Gnaa is a Teledyne Webb Research 1000m electric glider (Slocum G1, SN103). The glider was equipped with an upumped Seabird conductivity-temperature (SN 0069), a Wetlab ECO-puck (fluorescence and turbidity, FLNTU SN 771), an Andreraa oxygen Optode (3830, SN 903), and an integrated RSI MicroRider (MR-1000-LP, SN059) with two shear probes (S1=M833, oriented vertical; S2=M666 oriented horizontal) and two thermistors (T1=T864, T2=T996; both sensors malfunctioned) for measuring turbulence microstructure. Both the CTD and the MR were configured to sample during dives and climbs of the glider. The data from the MR include measurements from 2 shear probes, 2-axis piezo-accelerometers (vibration), an inclinometer (pitch and roll) and a pressure transducer. The pressure transducer was damaged and we rely on the pressure record from the glider's sensors. Data from both thermistors were of low quality and are not included in the files. Turbulence channels sampled at a rate of 512 per second, and the slow channels at 64 per second. The glider was operated with fixed battery positions during dives and climbs to reduce vibrations from the servo mode. Shallower dives prior to fixing the battery position are excluded from the data set. In total 106 files are processed, out of a total of 114, excluding the short files when the glider was on deck or at the surface. The 106 files resulted in 212 sections. A section (a more general term for a profile) is a continuous part of the time series that has been selected for dissipation estimates. As the glider moves through the water while collecting data, its flight characteristics may change and at times may not meet the conditions necessary for good dissipation estimates. This can result in multiple separated sections of dissipation estimates per dive or climb. Each such section has a unique section identifier number. The two NetCDF files described below are constructed from the 212 sections. Users interested in concatenated dissipation profiles and 1-second time-averaged sensor data can use these files and avoid downloading of full records from the individual NC files. MERGED_SLOW contains the data from selected sensors, along with flight parameters, averaged in 1-second windows, and then concatenated in a 1-D time series. MERGED_EPSI contains dissipation rate estimates together with quality control parameters concatenated in a 1-D time series. The processing of the data and the format of this data set follows the recommendations and guidelines of the SCOR Working Group 160, ATOMIX (https://atomix.app.uib.no/), as decribed in Lueck et al. (2024). The processing was based on the standard Matlab routines provided by Rockland Scientific, which were adjusted for the ATOMIX recommendations. The glider data are processed using the GEOMAR Matlab Slocum glider processing toolbox (Krahmann, 2023). Spectral calculation and dissipation rate estimate details are given in the attributes and processing parameters. Spectra are obtained using 2-s fft length. Dissipation estimates are obtained over 10 s segments, overlapping by 5 s (50% overlap), using the cleaned shear spectra using the Goodman method and the Lueck model spectrum. The short fft length is not ideal for resolving low dissipation rates, but was necessary to avoid the contamination at low wavenumbers from glider motion. The concatenated time series differ from the individual NC files as follows. 1) When producing the merged files, in addition to the automated quality assurance during the processing, we performed manual quality screening and updated the flag values. The screening removed data (i.e., replaced with NaN) during times with malfunctioning probes, contamination from altimeter effects, abrupt flight behavior changes, and when hotel data were not available. More details can be found in the description and attributes of the two merged NC files. Data quality flags for dissipation estimates are summarized in the attributes of the variable EPSI_FLAGS. In particular, we used a FOM threshold of 1.3. For dissipation estimates less than 1e-10 W/kg, we relaxed this threshold to a value of two, as this parameter is not well-constrained for low dissipation rates. We observed systematically larger FOM values with decreasing dissipation rates, most with marginally acceptable estimates. This choice was made to retain noise-level estimates instead of introducing gaps in the data. Users may want to apply additional quality screening. In the MERGED_EPSI file, quality flags are applied to EPSI_FINAL time series. A final dissipation estimate, EPSI_FINAL, failing the data quality control is reported as NaN; however, the individual dissipation estimates from each probe are accessible in the EPSI parameter. 2) The practical salinity and temperature from the glider are corrected against shipboard measurements using constant offsets of Toffset = -0.044C and Soffset = 0.0077 (in the form Scorrected = Smeasured + Soffset). Finally, 1-s salinity are de-spiked using a 5 point median filter and 2 standard deviations threshold. Potential density anomaly is re-calculated, similarly de-spiked and slightly smoothed using 11 point moving mean. The corrections, de-spiking and smoothing are not applied in the individual NC files. The data in the concatenated files are not gridded in time or pressure. Each data point has its own time stamp and a pressure value, with time increasing monotonically from the start of the first section. Sections when the glider ascends (climbs) will therefore have pressure values decreasing with time.' conventions = 'CF-1.6, ACDD-1.3, ATOMIX-1.0' history = 'Version 1' area = 'Norwegian Sea' geospatial_lat_min = 69.9 geospatial_lat_max = 70.3 geospatial_lon_min = 0.7 geospatial_lon_max = 2.6 geospatial_vertical_min = 1 geospatial_vertical_max = 311 geospatial_vertical_positive = 'down' time_coverage_start = '2017-09-06T17:00:42Z' time_coverage_end = '2017-09-12T04:22:43Z' creator_name = 'Fer, Ilker' creator_email = 'ilker.fer@uib.no' creator_url = 'https://www.uib.no/gfi' institution = 'Geophysical Institute, University of Bergen, Norway' authors = 'Fer, Ilker; Bosse, Anthony' project_name = 'PROVOLO' cruise = 'KB2017618' vessel = 'F.F. Kristine Bonnevie' principal_investigator = 'Fer, Ilker' contact = 'ilker.fer@uib.no' references = 'https://atomix.app.uib.no/; Lueck, R., I. Fer, C. E. Bluteau, M. Dengler, H. P., R. Inoue, A. LeBoyer, S.-A. Nicholson, K. Schulz, and C. Stevens (2024), Best practices recommendations for estimating dissipation rates from shear probes, Frontiers in Marine Science, 11, https://doi.org/10.3389/fmars.2024.1334327. Krahmann, Gerd (2023) GEOMAR FB1-PO Matlab Slocum glider processing toolbox. https://doi.org/10.3289/SW_4_2023.' acknowledgements = 'This data set is made possible by the funding from the Research Council of Norway' keywords = 'Norwegian Sea, Lofoten Basin, glider, mixing, turbulence, dissipation rate, microstructure, shear probes' source = 'sub-surface glider' license = 'http://creativecommons.org/licenses/by/4.0/' citation = 'Fer, Ilker and Anthony Bosse (2024), Dissipation measurements from a Slocum glider in the Lofoten Basin, September 2017. [Dataset] Norwegian Marine Data Centre, https://doi.org/10.21335/NMDC-1469977935' instrument = 'MicroRider-1000LP' instrument_serial_number = 59 instrument_sample_rate = 512 instrument_sampling_mode = 'continuous' profiling_direction = 'glide' time_reference_year = 0 fs_fast = 512 fft_length_sec = 2 diss_length_sec = 10 fft_length = 1024 diss_length = 5120 overlap = 2560 goodman = 1 HP_cut = 0.25 despike_shear_fraction_limit = 0.15 FOM_limit = 1.3 diss_ratio_limit = 2.772 despike_shear_iterations_limit = 8 creation_time = '2024-08-08T14:05:26Z' date_modified = '2024-08-08T14:05:26Z' date_created = '2024-08-08' Dimensions: TIME_DIM = 69937 N_SHEAR_SENSORS = 2 Variables: TIME Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'time' units = 'Days since 0000-01-00T00:00:00Z' axis = 'T' long_name = 'Serial date number' calendar = 'proleptic_gregorian' comment = 'Standard MATLAB serial date number. It represents the fractional number of days from a fixed, preset date (January 0, 0000) in the proleptic ISO calendar. 1 January noon is day 1.5.' EPSI Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'specific_turbulent_kinetic_energy_dissipation_in_sea_water' units = 'W kg-1' long_name = 'dissipation rate of turbulent kinetic energy per unit mass in sea water estimated from individual shear probes' EPSI_FINAL Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'specific_turbulent_kinetic_energy_dissipation_in_sea_water' units = 'W kg-1' long_name = 'dissipation rate of turbulent kinetic energy per unit mass in sea water averaged using all accepted shear probes' KMAX Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'maximum_wavenumber_used_for_estimating_turbulent_kinetic_energy_dissipation' units = 'cpm' long_name = 'maximum wavenumber for integration of shear spectrum' N_S Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: int32 Attributes: standard_name = 'number_of_spectral_points_used_for_estimating_turbulent_kinetic_energy_dissipation' units = '1' long_name = 'number of spectral points used for estimating turbulent kinetic energy dissipation' comment = 'it is the same for the integration or the fit method' SECTION_NUMBER Size: 69937x1 Dimensions: TIME_DIM Datatype: int32 Attributes: standard_name = 'unique_identifier_for_each_section_of_data_from_timeseries' units = '1' long_name = 'A unique indentifier counter defining sections of the time series extracted for dissipation estimates' PSPD_REL Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'platform_speed_wrt_sea_water' units = 'm s-1' long_name = 'Platform speed with respect to sea water' METHOD Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: int32 Attributes: standard_name = 'method_used_for_estimating_turbulent_kinetic_energy_dissipation' units = '1' long_name = 'method for dissipation rate estimation: 0 is spectral integration in the viscous subrange. 1 is spectral fit to the inertial subrange.' comment = '0 is spectral integration in the viscous subrange. 1 is spectral fit to the inertial subrange.' LON Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'longitude' units = 'degree_east' long_name = 'longitude' LAT Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'latitude' units = 'degree_north' long_name = 'latitude' FILE_NUM Size: 69937x1 Dimensions: TIME_DIM Datatype: int32 Attributes: standard_name = 'file_number' units = '1' long_name = 'file or cast number/counter of the native instrument file' PRES Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_pressure' units = 'decibar' long_name = 'Sea water pressure, equals 0 at sea-level' TEMP Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'sea_water_temperature' units = 'degree_Celsius' long_name = 'sea water temperature in-situ ITS-90 scale' FOM Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'figure_of_merit' units = '1' long_name = 'Ratio of the MAD of the spectrum to the 97.5 percentile of the expected MAD for the number of spectral points used to estimate the rate of dissipation' comment = 'If the number of spectral points is N, and the expected standard deviation of the natural logarithm of spectrum of shear is sig, expected MAD is sigx(0.8+(1.25/sqrt(N))). If the spectrum is calculated using number of FFT segments Nf, and cleaned using Nv vibration signals, sig = sqrt ( 5/4 ((Nf - Nv)^(-7/9))).' MAD Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'mean_absolute_deviation' units = '1' long_name = 'mean absolute deviation (MAD) of the natural logarithm of the shear spectrum from the logarithm of a reference spectrum for the estimated rate of dissipation' comment = 'MAD of the spectrum is calculated using the wavenumbers upto KMAX, relative to the model spectrum, using: e.g., mean(abs(log(observed_spectrum/model_spectrum)))' VAR_RESOLVED Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'variance_resolved' units = '1' long_name = 'variance resolved in the spectra used for the estimate rate of dissipation' EPSI_STD Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'expected_standard_deviation_of_the_logarithm_of_the_dissipation_estimate' units = '1' long_name = 'For estimates in the viscous subrange, EPSI_STD = sqrt(5.5 / (1 + (Lf/4)^(7/9))), whereLf = (L/Lk)(VAR_RESOLVED^(3/4)), and L is the data length in meters used for spectral estimate, Lk is the Kolmogorov length, and VAR_RESOLVED is the variance resolved in the spectra used for the estimate rate of dissipation.' KVISC Size: 69937x1 Dimensions: TIME_DIM Datatype: double Attributes: standard_name = 'kinematic_viscosity_of_water' units = 'm2 s-1' long_name = 'Kinematic viscosity of sea water' DESPIKE_FRACTION_SH Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'fraction_of_shear_data_modified_by_despiking_algorithm' units = '1' long_name = 'fraction of data, within a segment, that was modified by the despiking algorithm for the shear probes' DESPIKE_PASS_COUNT_SH Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: double Attributes: standard_name = 'number_of_despike_passes_for_shear_probes' units = '1' long_name = 'the number of passes ran with despiking routine to obtain a clean times series of shear probes. One value per section per probe' EPSI_FLAGS Size: 69937x2 Dimensions: TIME_DIM,N_SHEAR_SENSORS Datatype: int32 Attributes: standard_name = 'dissipation_qc_flag' units = '1' long_name = 'quality control coding for dissipation estimate from each shear probe ' conventions = 'ATOMIX, shear probes group' flag_values = [0 1 2 4 8 16 32 64 128 256] flag_meanings = '0: Good, 1: Poor figure of merit (FOM>FOM_limit), 2: Large fraction of data with spikes (despike_shear_fraction > despike_shear_fraction_limit), 4: Anomalously large disagreement between dissipation estimates from probes (|log(e_max)-log(e_min)|> diss_ratio_limit * EPSI_STD), 8: Too many iterations of despiking routine (despike_shear_iterations > despike_shear_iterations_limit), 16: Insufficient variance resolved (VAR_RESOLVED>