Janout, Markus A; Hölemann, Jens A; Timokhov, Leonid (2019): Physical oceanography from underway CTD measurements during the Transdrift 22-expedition to the Laptev Sea in 2014 [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.907936
Always quote citation above when using data! You can download the citation in several formats below.
Abstract:
Underway (U)CTD data were collected during a 2014 expedition (3. September – 10. October) to the Arctic Ocean aboard the RV Viktor Buinitsky as part of the German-Russian BMBF-funded project Transdrift (The transpolar system of the Arctic Ocean). The UCTD was operated during selected shelf-basin transects as well as to expand the sampling grid on the shelf during transit across the shelf while the ship was transiting with 6 - 11 knots. The UCTD probe records the start time of the measurements and stores 16 samples each second internally. The exact location of each profile was subsequently found based on the time stamp from the cruise track. The unpumped conductivity sensor has a slower response time than the temperature sensor, which makes the computation of salinity from conductivity and temperature potentially spiky, especially in the pycnocline or in frontal regions. We followed the recommendation of the manufacturer to calculate salinity with Seabird processing software. The raw data profiles are provided as well and can be reprocessed if desired. In shallower waters (<200m), the water column was profiled all the way to the seafloor, while in deeper waters, only the upper 200-350m were sampled. Shipboard echo soundings were not available, actual water depths at the profile locations need to be extracted from bathymetric charts (for instance IBCAO ). The UCTD sensors were calibrated before and after the cruise. The upper 3 m of the data were discarded due to the influence of the ship. However, the hull of the ship was shallow and the effect of the ship on mixing surface water properties and disrupting the natural water column structure was relatively small compared with large vessels.
Related to:
Janout, Markus A; Aksenov, Yevgeny; Hölemann, Jens A; Rabe, Benjamin; Schauer, Ursula; Polyakov, Igor; Bacon, Sheldon; Coward, Andrew; Karcher, Michael J; Lenn, Yueng-Djern; Kassens, Heidemarie; Timokhov, Leonid (2015): Kara Sea freshwater transport through Vilkitsky Strait: Variability, forcing, and further pathways toward the western Arctic Ocean from a model and observations. Journal of Geophysical Research: Oceans, 120(7), 4925-4944, https://doi.org/10.1002/2014JC010635
Janout, Markus A; Hölemann, Jens A; Timokhov, Leonid; Gutjahr, Oliver; Heinemann, Günther (2017): Circulation in the northwest Laptev Sea in the eastern Arctic Ocean: Crossroads between Siberian River water, Atlantic water and polynya-formed dense water. Journal of Geophysical Research: Oceans, 122(8), 6630-6647, https://doi.org/10.1002/2017JC013159
Other version:
Further details:
Rudnick, Daniel; Klinke, Jochen (2007): The Underway Conductivity–Temperature–Depth instrument. Journal of Atmospheric and Oceanic Technology, 24(11), 1910-1923, https://doi.org/10.1175/JTECH2100.1
Project(s):
Laptev Sea System (LSS)
Physical Oceanography @ AWI (AWI_PhyOce)
System Laptev-Sea: Transdrift (TRANSDRIFT)
Funding:
Federal Ministry of Education and Research (BMBF), grant/award no. 03G0833B: Verbundprojekt: WTZ RUS: System Laptev-See: TRANSDRIFT
Coverage:
Median Latitude: 77.285385 * Median Longitude: 117.461565 * South-bound Latitude: 73.547000 * West-bound Longitude: 107.150000 * North-bound Latitude: 78.328000 * East-bound Longitude: 134.660000
Date/Time Start: 2014-09-13T07:22:00 * Date/Time End: 2014-09-27T23:59:00
Minimum DEPTH, water: 3.96 m * Maximum DEPTH, water: 327.26 m
Event(s):
VB14_1-1a * Latitude: 77.509000 * Longitude: 107.146000 * Date/Time: 2014-09-13T07:22:00 * Elevation: -73.0 m * Location: Laptev Sea * Campaign: Transdrift-XXII (VB14) * Basis: Viktor Buynitskiy * Method/Device: CTD, underway (CTD-UW)
VB14_1-1b * Latitude: 77.521000 * Longitude: 107.161000 * Date/Time: 2014-09-13T07:29:00 * Elevation: -73.0 m * Location: Laptev Sea * Campaign: Transdrift-XXII (VB14) * Basis: Viktor Buynitskiy * Method/Device: CTD, underway (CTD-UW)
VB14_1-1c * Latitude: 77.547000 * Longitude: 107.204000 * Date/Time: 2014-09-13T07:45:00 * Elevation: -73.0 m * Location: Laptev Sea * Campaign: Transdrift-XXII (VB14) * Basis: Viktor Buynitskiy * Method/Device: CTD, underway (CTD-UW)
Comment:
The underway CTD manufactured by Ocean Science is a self-contained free-falling probe measuring temperature, conductivity, depth while the ship is transiting. The conductivity sensor is unpumped, and has a response time that is different from that of the temperature sensor. Therefore, converting conductivity into salinity is not straightforward. We followed the recommendation of the manufacturer and computed salinity by use of the Seabird processing software as outlined in the document “UCTD salinity”.
The processed data file includes temperature, pressure, and salinity. The Viktor Buinitsky is a middle-sized vessel and therefore we consider only the upper 4 m untrustworthy due to the ship's influence.
Additional information about the underway CTD can be found in Rudnick, D. L., and J. Klinke, 2007.
The raw data are also included and can be used to reprocess the salinity data if desired.
Parameter(s):
| # | Name | Short Name | Unit | Principal Investigator | Method/Device | Comment |
|---|---|---|---|---|---|---|
| 1 | Event label | Event | Janout, Markus A | |||
| 2 | Profile ID | Profile ID | Janout, Markus A | |||
| 3 | DATE/TIME | Date/Time | Janout, Markus A | Geocode | ||
| 4 | LATITUDE | Latitude | Janout, Markus A | Geocode | ||
| 5 | LONGITUDE | Longitude | Janout, Markus A | Geocode | ||
| 6 | Pressure, water | Press | dbar | Janout, Markus A | UnderwayCTD (UCTD), Oceanscience | |
| 7 | DEPTH, water | Depth water | m | Janout, Markus A | UnderwayCTD (UCTD), Oceanscience | Geocode |
| 8 | Temperature, water | Temp | °C | Janout, Markus A | UnderwayCTD (UCTD), Oceanscience | ITS-90 |
| 9 | Salinity | Sal | Janout, Markus A | UnderwayCTD (UCTD), Oceanscience | PSU |
License:
Creative Commons Attribution 4.0 International (CC-BY-4.0)
Size:
108084 data points
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