Current velocity measurements from upward-looking ADCP at Qikiqtaruk during the Yukon Coast 2015 expedition of the AWI

• Main Authors: Gimsa, Justus, Tanski, George, Irrgang, Anna Maria, Fritz, Michael, Lantuit, Hugues, Radosavljevic, Boris
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2021
• Subjects: Acoustic Current Doppler Profiler; ADCP; ADCP data; Arctic Ocean; Arctic Shelf; Beaufort Sea; Coastal erosion; currents; current velocity; Herschel Island; hydrodynamics; Nearshore zone; permafrost; Qikiqtaruk; Yukon Coast; Date/Time local; Height above sea floor/altitude; Current velocity, east-west; Current velocity, north-south; Acoustic Doppler Current Profiling ADCP; Acoustic Doppler Current Profiling ADCP, RDI Workhorse Sentinel, 600 kHz; CA-Land_2015_YukonCoast; AWI Arctic Land Expedition; Permafrost Research AWI_Perma; Arctic; Yukon; Janus; Herschel
• Online Access: https://dx.doi.org/10.1594/pangaea.931914; https://doi.pangaea.de/10.1594/PANGAEA.931914

The dataset compiles water current velocities and direction measured by a platform-based upward looking Acoustic Doppler Current Profiler. Data was acquired in July/August 2015 during the Yukon Coast 2015 expedition to the Herschel Island – Qikiqtaruk coastal observatory, conducted by the Alfred Wegener Institute in Potsdam, Germany. Goal of this project was to find drivers that control nearshore currents and to map their spatio-temporal variation. These currents might play an important role in the transport process of sediments and organic matter in the nearshore zone of the Arctic Ocean. The sediments mainly originate from the rapidly eroding permafrost coasts. The columns of this data file include Date/Time, height above the seafloor of the respective measurement cell (bin), current velocity in east-west direction and current velocity in north-south direction. : Data description:Setting: 4 Beam in 20 degree Janus configurationDeployment location: Latitude 69.558393 N / Longitude 138.914445 WDepth: ca. 11 meter - (varying with sea level)Number of cells (bins): 29Bin size: 0.50 meter First bin: 1.60 meter Measurements per hour: 4Pings per Ensemble: 50 Time/Ping: 18.00 sData is given in "oceanographic convention" (i.e. the direction the current is directed to)Pre- and post-processing steps:Step 1 - Calibration of the instrument by following the calibration setup in the software (RD Instrument WinSC)Step 2 – Definition of planned deployment schedule and parameterization of the device (RD Instrument WinSc + RD Instrument PlanADCP)Step 3 - Deployment of the ADCP with a ZODIAC at the study site using a bottom mooring mounted on a stainless steel plateStep 4 - Retrieval of the instrument after 16 daysStep 5 - Download of the collected dataStep 6 - Opening of the data files with RDI VelocityStep 7 – Adjustment of the raw data for the following parameters using RDI Velocity software and the corresponding "Velocity Users Guide":a) Magnetic declination (accessed from https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#declination; Magnetic declination = 22.27 degreeb) Salinity (average value derived from 6 point measurements through the water column with data ~0.3 meter) analysed from water column profiles retrieved with a handheld CastAway CTD near the ADCP mooring; Salinity = 24.91 ppt (parts per thousand)c) Speed of sound velocities were recalculated using temperature, salinity and depthd) Surface boundary: Contaminated upper bins were removed (blank) using the "Range to boundary - Intensity" function of Velocity, to remove measurements that were affected by turbulent air bubbles from wave action.Step 8 - Exporting the processed files to Matlab using the Velocity Export function; Data right after lowering the mooring system and after retrieving was removed; Step 9 – Writing of txt-file in Matlab (tab delimiter, ISO 8601 date format, UTF-8, missing or removed data is left empty)