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
The following example shows how to cite the use of this data set in a publication. 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
- Contacts and Acknowledgments
- Detailed Data Description
- Data Access and Tools
- Data Acquisition and Processing
- References and Related Publications
- 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.
| 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:
| 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.
| 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
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