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Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples

Summary

This data set is part of the West Antarctic Ice Sheet cores (WAISCORES) project, an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice cores from the Siple Dome, in the Siple Coast region, West Antarctica. Siple Dome ice cores were analyzed for methanesulfonate (MSA) and carbonyl sulfide (OCS). The methanesulfonate analysis was done on cores A-E and a hot water core, and the carbonyl sulfide analysis was done on 11 C cores. Methanesulfonate data include the sample identification number, depth, and methanesulfonate parts per billion (ppb) of each sample. Carbonyl sulfide data include the depth, OCS parts per trillion (ppt) of each sample, percent error, and gas age (years). Data are available via FTP in tab-delimited ASCII text (.dat, .txt) file 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, publisher: NSIDC, and digital media.

Saltzman, E. and M. Aydin. 2003. Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5P848VP.

Overview Table

Category Description
Data format ASCII data (.dat) and text files (.txt)
Spatial coverage and resolution Southernmost Latitude: 81°S
Northernmost Latitude: 81°S
Westernmost Longitude: 149°W
Easternmost Longitude: 148°W
Temporal coverage and resolution Data were obtained during three Antarctic field seasons in 1996 to 1999.
File naming convention msaA1.dat
msaA2.dat
msaC.dat
msaHW.dat
OCSdata.txt
File size The data set is 58 KB total.
Parameter(s) Methanesulfonate concentration in parts per billion (ppb, 109)
Carbonyl sulfide concentration in parts per trillion (ppt, 1012)
Gas age in years
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

Investigator(s)

Dr. Eric Saltzman
University of California, Irvine
Department of Earth System Science
Irvine, California 92697
USA

Dr. Murat Aydin
University of California, Irvine
Department of Earth System Science
Irvine, California 92697
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 NSF OPP grant 0338359.

2. Detailed Data Description

Format

Data are available as tab-delimited ASCII text files (.dat, .txt).

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/waiscores/saltzman/ directory. Table 1 lists the files in this directory:

Table 1. Files in the /AGDC/waiscores/saltzman/ directory
File Name Description
msaA1.dat
msaA2.dat
msaB.dat
msaC.dat
msaE.dat
msaHW.dat
Methanesulfonate analysis for ice cores A through E and a hot water core
msameta.html Notes related to the methanesulfonate data, available as an HTML file
OCSdata.txt Carbonyl sulfide analysis for 11 C ice cores, available as a tab-delimited ASCII text file
OCSmeta.txt Notes related to the carbonyl sulfide data, available as an ASCII text file

File Naming Convention

Files are named according to the following convention and as described in Table 2:

xxxid.zzz

Where:

Table 2. File Naming Convention
Variable Description
xxx Analysis type, msa or OCS
id Core site identification:
  • Two core site A samples, A1 and A2
  • Core samples from core sites B, C, E
  • Hot water core sample, HW
  • Core sample from 11 C core sites, data
.zzz File Extension type:
  • .dat for methanesulfonate analysis data
  • .txt for carbonyl sulfide analysis data

File Size

The data set contains 10 files ranging in size from 1 KB to 14 KB.

Spatial Coverage

Ice core data were collected at the Siple Dome site in the Siple Coast region of Antarctica.

Southernmost Latitude: 81°S
Northernmost Latitude: 81°S
Westernmost Longitude: 149°W
Easternmost Longitude: 148°W

Temporal Coverage

Data were obtained during three Antarctic field seasons in 1996 to 1999.

Parameter or Variable

Parameters for methanesulfonate analysis include the depth in meters (m) and methanesulfonate ion concentration in parts per billion (ppb). Parameters for carbonyl sulfide analysis include depth in meters (m), carbonyl sulfide ion concentration in parts per trillion (ppt), the percent error of the concentration (%), and the gas age in years.

Parameter Description

Carbonyl sulfide(OCS) and methane sulfonate (MSA) data files include methanesulfonate and carbonyl sulfide concentration measurements for ice cores at Siple Dome summit. Table 3 provides details on the files and parameters.

Table 3. OCS and MSA Data Files and Parameters
Parameter Description
Methanesulfonate Analysis
MSA analysis Files containing sample ID, measurement depth, and ion concentration in parts per billion (ppb)
Carbonyl Sulfide Analysis
OCS analysis File containing measurement depth, ion concentration in parts per trillion (ppt), percent error of ion concentration (%), and gas age in years

Sample Data Record

Below are two sample records from the Methane Analysis and Carbonyl Sulfide Analysis data files. Only the first four data records are shown from each data file. The Methane Analysis sample record is from msaA1.dat and the Carbonyl Sulfide Analysis sample record is from OCSdata.txt.

Methane Analysis:

Sample Id Top Depth (m) MSA (ppb)
Siple 1 4.32 13.63
2-SIPLE 4.83 14.66
Siple 3 5.61 26.11
Siple 4 6.29 16.09

Carbonyl Sulfide Analysis:

depth (m) OCS (ppt) error (%) gas age (years)
88.645 392.5 7.0 376.7
84.820 432.7 5.6 341.8
86.570 380.7 4.1 357.6
82.290 337.0 4.5 315.8

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total volume of the data set is 58 KB.

Software and Tools

Data are accessible using standard spreadsheet software.

Related Data Collections

4. Data Acquisition and Processing

Analysis of the ice core sub-samples for methanesulfonate was carried out using chemically suppressed ion chromatography. Carbonyl sulfide concentration was measured in air extracted from 11 ice cores. Air trapped in the ice cores was released using a dry extraction technique and analyzed by a gas chromatography with mass selective detection. For more information on data acquisition methods, see the researchers' notes in the msameta.html and OCSmeta.txt files and the References and Related Publications listed below.

5. References and Related Publications

Aydin, M., W. J. De Bruyn, and E. S. Saltzman. 2002. Preindustrial Atmospheric Carbonyl Sulfide (OCS) from an Antarctic Ice Core. Geophysical Research Letters 29(9), 1359: doi:10.1029/2002GL014796.

Etheridge, D. M., G. I. Pearman, and F. de Silva. 1988. Atmospheric Trace-gas Variations as Revealed by Air Trapped in an Ice Core from Law Dome, Antarctica. Annals of Glaciology 10, 28-33.

Schwander, J. 1989. The Transformation of Snow to Ice and the Occlusion of Gases. In The Environmental Record in Glaciers and Ice Sheets, edited by H. Oeschger and C. C. Langway. John Wiley, New York.

Schwander, J., B. Stauffer, and A. Sigg. 1988. Air Mixing in Firn and the Age of the Air at Pore Close-off. Annals of Glaciology 10, 141-145.

Sowers, T. and J. Jubenville. 2000. A Modified Extraction Technique for Liberating Occluded Gases from Ice Cores. Journal of Geophysical Research 105, 29155-29164: doi:10.1029/2000JD900335.

Trudinger, C. M., I. G. Enting, D. M. Etheridge, R. J. Francey, V. A. Levchenko, L. P. Steele, D. Raynaud, and L. Arnaud. 1997. Modeling Air Movement and Bubble Trapping in Firn. Journal of Geophysical Research 102, 6747-6763.

Table 4 list related documents that are available on the NSIDC Web site.

Table 4. Related Documents
Document Description URL
WAISCORES Project Web site http://nsidc.org/data/waiscores/
Antarctic Glaciological Data Center Data center Web site http://nsidc.org/agdc/

6. Document Information

Acronyms

The acronyms used in this document are listed in Table 5.

Table 5. Acronyms and Abbreviations
Acronym Description
.DAT Data file extension
FTP File Transfer Protocol
HTML Hypertext Markup Language
MSA Methanesulfonate
NSIDC National Snow and Ice Data Center
OCS Carbonyl sulfide
PPB Parts per billion, 109
PPT Parts per trillion, 1012
.TXT Text file extension
URL Uniform Resource Locator
WAISCORES Western Divide West Antarctic Ice Cores

Document Creation Date

9 September 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0131_saltzman/index.html