Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica

Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica

Summary

This data set provides a modeled radar attenuation rate profile, showing the predicted contributions from pure ice and impurities to radar attenuation at the Vostok 5G ice core site in Antarctica, as well as the total attenuation rate and its formal uncertainty. The model data are based on borehole temperature logs, concentrations of major soluble ions measured from melted ice core samples, and information about the electrical conductivity of ice. Attenuation rates and their spatial variability are important constraints for radar studies of ice sheets. Parameters include depth (m), total attenuation rate (dB/km), and attenuation rate contribution from pure ice, acidity, and salinity.

Data are available via FTP as a text file (.txt) with columns in comma separated value format.

Citing These Data

We kindly request that you cite the use of this data set in a publication using the following citation example. For more information, see our Use and Copyright Web page.

The following example shows how to cite the use of this data set in a publication. List the principal investigators, year of data set release, data set title, publisher: NSIDC, and digital media.

MacGregor, J., K. Matsuoka, and M. Studinger. 2011. Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N59K485D.

Overview Table

Category Description
Data format ASCII Text (.txt) format
Spatial coverage and resolution Southernmost Latitude: 78.47°S
Northernmost Latitude: 78.47°S
Westernmost Longitude: 73.17°E
Easternmost Longitude: 73.17°E
Temporal coverage and resolution Data were collected in 2007 and 2008
File naming convention vostok_atten.txt
File size 15 KB
Parameters Depth
Total Attenuation Rate
Attenuation Rate Contribution from Pure Ice
Attenuation Rate Contribution from Acidity
Attenuation Rate Contribution from Salinity
Uncertainty
Procedures for obtaining data Data are available via FTP.

Table of Contents

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

1. Contacts and Acknowledgments

Investigators

Dr. Joseph A. MacGregor
University of Texas at Austin
10100 Burnet Road, Bldg. 196
Austin, TX 78758
USA

Dr. Kenichi Matsuoka
Department of Earth and Space Sciences
University of Washington
Department of Earth and Space Sciences
Seattle, WA 98105
USA

Dr. Michael Studinger
Lamont-Doherty Earth Observatory
61 Route 9W
Palisades, NY 10964
USA

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

Acknowledgements

This research was supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) grant number 0538674.

2. Detailed Data Description

Format

Data are in ASCII text format (.txt), with columns in comma separated value format.

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0501_macgregor_V01/ directory. The data set consists of one data file, vostok_atten.txt.

File Size

The data file is 15 KB.

Spatial Coverage

The model is based on borehole and ice core data from the Vostok 5G ice core.

Southernmost Latitude: 78.47°S
Northernmost Latitude: 78.47°S
Westernmost Longitude: 73.17°E
Easternmost Longitude: 73.17°E

Spatial Resolution

10 m depth

Temporal Coverage

Data used for the model were collected in 2007 and 2008.

Parameter or Variable

These data consist of a modeled radar attenuation rate profile, based on data from the Vostok 5G ice core. Parameters include depth, total attenuation rate, and attenuation rate contribution from pure ice, acidity, and salinity. Attenuation rate is measured in decibels (dB) per kilometer.

Parameter Description

Table 1 describes the columns and parameters in the vostok_atten.txt file.

Table 1. Parameter Description
Column Number Description
1 Depth of Midpoint for interval (m)
2 Attenuation Rate Contribution from Pure Ice (dB/km)
3 Attenuation Rate Contribution from Acidity / H+ (dB/km)
4 Attenuation Rate Contribution from Salinity / Sea Salt Cl- (dB/km)
5 Total Attenuation Rate (dB/km)
6 Total Attenuation Rate Uncertainty (dB/km)

Sample Data Record

This table shows the first three records in the vostok_atten.txt file. The file has no
header row: columns are listed at the top of the file, as well as under Parameter Description, above.

5

0.090974

0

0.01384

0.10481

0.14761

15

0.097435

0

0.015841

0.11328

0.17125

25

0.11442

0

0.019312

0.13373

0.20899

 

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

15 KB.

Related Data Collections

4. Data Acquisition and Processing

Theory of Measurements

Radar attenuation rates are based on data from the Vostok 5G ice core, include borehole temperature logs, major soluble ion concentrations measured from melted ice core samples, combined with researchers' present understanding of the radio frequency electrical conductivity of ice. The radar attenuation rates were modeled following work by MacGregor, et. al., 2009 and 2007.

5. References and Related Publications

MacGregor, J. A., D. P. Winebrenner, H. Conway, K. Matsuoka, P. A. Mayewski, and G. D. Clow. 2007. Modeling Englacial Radar Attenuation at Siple Dome, West Antarctica, Using Ice Chemistry and Temperature Data, Journal of Geophysical Research, 112, F03008, doi:10.1029/2006JF000717.

MacGregor, J.A., K. Matsuoka and M. Studinger. 2009. Radar Detection of Accreted Ice over Lake Vostok, Antarctica, Earth and Planetary Science Letters, 282(1-4), 222-233.

The following related documents are available:

Table 2. Related Documents
Document Description URL
AGDC Home Page Data Center Home Page http://nsidc.org/agdc
Vostok Ice Core National Ice Core Laboratory, Ice Core Locations http://nicl.usgs.gov/ant-v.nicl

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 3. Acronyms and Abbreviations
Acronym Description
dB Decibels
FTP File Transfer Protocol
NSIDC National Snow and Ice Data Center
URL Uniform Resource Locator

Document Creation Date

24 August 2011

Document URL

http://nsidc.org/data/docs/agdc/nsidc0501_macgregor1/index.html