Svalbard Fjord Conductivity, Temperature, Depth Data, 2001-2004

Summary

This data set includes vertical ocean profiles of temperature, salinity and backscatter beneath ice cover in Svalbard Fjord, Norway. The data were collected by a Seabird Conductivity-Temperature-Depth (CTD) system mounted on a remotely operated vehicle (ROV) on three trips: the north side of Van Mijenfjorden in March 2001; the south of Van Mijenfjorden in March 2004; the south of Van Mijenfjorden in June 2004. To address the differences between theory and observation regarding the rate of ice formation, supercooling in the ocean boundary layer, and the effective diffusivities of heat and salt, the small-scale physics of sea ice formation were studied. This data set is available as tab-delimited ASCII text files, sizes 32 KB to 2,033 KB.

Citing These Data

The following example shows how to cite these data in a publication. List the principal investigators, year of data set release, data set title and version, dates of the version you used, publisher (NCAR), ARCSS Data Archive.

Morison, J., J. Wettlaufer, D. Morison, and R. Andersen. 2005. Svalbard Fjord Conductivity, Temperature, Depth Data, 2001-2004. Boulder, CO: National Center for Atmospheric Research, ARCSs Data Archive.

Overview Table

Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. Document Information

1. Contacts and Acknowledgments

Investigator(s) Name and Title

James Morison
Polar Science Center
Applied Physics Lab
University of Washington
1013 NE 40th
Seattle, WA 98105-6698 USA

John Wettlaufer
University of Washington
1100 NE 45th St., Suite 300
Seattle, WA 98105-6698 USA

Technical Contacts

Acknowledgements

The National Science Foundation (NSF) Arctic Natural Sciences, Arctic Research Support and Logistics programs funded the data project.
The following grant applies: National Science Foundation Grant OPP-0082687: Collaborative Study of Ice-Ocean Interaction in Svalbard.

2. Detailed Data Description

To address the paradoxes about the rate of ice formation, supercooling in the ocean boundary layer, and the effective diffusivities of heat and salt, the small-scale physics of sea ice formation was studied in Svalbard Fjord. The exchange of heat and salt at the ice-ocean interface is an important facet in the energy balance, but a significant gap exists between theory and observation. To test the hypotheosis that existing boundary layer theories do not accurately represent the microphysics of the ice formation process, observational and theoretical investigations were conducted. Fast ice in frozen but tidally active fjords in Svalbard offered a natural laboratory in which the small-scale ice-ocean interaction could be investigated.

The data were collected by a Seabird Conductivity-Temperature-Depth (CTD) system mounted on a romotely operated vehicle (ROV) on three trips: the north side of Van Mijenfjorden in March 2001; the south of Van Mijenfjorden in March 2004; the south of Van Mijenfjorden in June 2004. This data set is available as tab-delimited ASCII text files, sizes 32 KB to 2,033 KB.

Format

Data is formatted in six columns:

File Naming Convention

Seamore.zip holds 24 text files containing data, two .jpg image files of the ROV, and a readme.txt file.
Each data text file is named after the ROV, Seamore, and is numbered 1-24; each file contains data for a specified time domain and location:

File Size

File sizes range from 32 KB to 2,033 KB.

Spatial Coverage

Offshore to the north side of Van Mijenfjorden in Svalbard Fjord and the south side of Van Mijenfjorden in serveral specific locations, approximately 77° 45' N, 014° 59' E.

Temporal Coverage

The data were collected in three trips:

• 07-10 March 2001, on the north side of Van Mijenfjorden
• 11-13 March 2004, the south of Van Mijenfjorden
• 06-11 June 2004, the south of Van Mijenfjorden

Parameter or Variable

Data Sample

Seamore1.txt
March 7,2001 09:49:00 GMT N 77 48.799 E 015 54.251

1 3.5020 2.7058340 -1.87260 0.16660 -1.78850
0 3.5020 2.7058400 -1.87260 0.16660 -1.78840
0 3.5000 2.7058450 -1.87260 0.16660 -1.78840
0 3.4980 2.7058490 -1.87260 0.16660 -1.78830
0 3.4940 2.7058530 -1.87260 0.16650 -1.78830
...

3. Data Access and Tools

Data are available for ordering throughNCAR

4. Data Acquisition and Processing

Sensor or Instrument Description

Seamore, a small ROV, was equipped with a SBE 19 plus SEACAT Profiler, a SBE 38 Temperature Recorder, a ~5 watt DC heater, and a Sea-Tech Optical Backscatter Sensor LS 6000.

Data Acquisition Methods

The data were collected in an upcast while Seamore floated up to the ice with its motors off.

Water pumped by the profiler first passes over the SBE 38 (data is represented in column 4), then over the heater and finally over the profiler's regular temperature probe (data is represented in column 6) and conductivity cell. A Sea-Tech Optical Backscatter Sensor LS 6000 recorded the data in column 5.

Processing Steps

Using Matlab, the pressure record was used to select the upcasts within each session. Because the inlet for the SBE 19 plus SEACAT Profiler is located on the top of the slightly buoyant ROV, the wake of the instrument and the running motor corrupt the data as the instrument decends. A '1' in the first column denotes the first row of a new upcast; the other data has been excluded and is repsented in the data sets as a '0'.

SBE Data Processing-Win32 software was used to filter all of the data in the time domain, advance the temperature measurement used for salinity calculation and compensate for the thermal mass of the conductivity cell.

5. Document Information

Document Creation Date

30 April 2005

Document URL

http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS150