Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica

Summary

This data set contains trace gas measurements of air extracted from ice core samples from the West Antarctic Ice Sheet Divide A core (WAIS-D 05A). The WAIS A ice core was dry-drilled at the WAIS site during the 2005-2006 Antarctic field season. Data include trace gas species including ethane (C2H6), propane (C3H8), n-butane (n-C4H10), carbonyl sulfide (COS), carbon disulfide (CS2), methyl chloride (CH3Cl), methyl bromide (CH3Br), acetonitrile (CH3CN), and chlorofluorocarbon-12 (CFC-12), for 57 ice core samples. The data are available via FTP in Microsoft Excel (.xls) file 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.

Saltzman, Eric. 2009. Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5251G40.

Overview Table

Category	Description
Data format	Microsoft Excel spreadsheet (.xls)
Spatial coverage and resolution	Southernmost Latitude: 79.47°S Northernmost Latitude: 79.47°S Westernmost Longitude: 112.09°E Easternmost Longitude: 112.09°E
Temporal coverage and resolution	2005 to 2006
File naming convention	SaltzmanWAISD05.xls
File size	36 KB
Parameter(s)	Trace gas species
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
3325 Croul Hall
Department of Earth System Science
University of California, Irvine
Irvine, California 92697 USA

Technical Contact

Acknowledgements

This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0440602.

2. Detailed Data Description

Format

Data are in Microsoft Excel (.xls) format.

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/saltzman_nsidc_0412/ directory. The data set is composed of one Microsoft Excel file, SaltzmanWAISD05.xls.

File Size

This data set is 36 KB.

Spatial Coverage

Trace gas data were measured from the WAIS-D 05A ice core, which was drilled at the West Antarctic Ice Sheet (WAIS) Divide site during the 2005-2006 Antarctic field season.

Southernmost Latitude: 79.47°S
Northernmost Latitude: 79.47°S
Westernmost Longitude: 112.09°E
Easternmost Longitude: 112.09°E

Temporal Coverage

The ice core was drilled during the 2005-2006 Antarctic field season. Measurements were taken during subsequent laboratory experiments.

Parameter or Variable

The SaltzmanWAISD05.xls file has 19 columns (A through S), the first one of which is the sample depth in meters. The remaining columns are the composition of the air extracted from the ice core samples with respect to each compound and the error (±1sigma) associated with each measurement, both expressed as dry air mixing ratios in parts per trillion (ppt).

Parameter Description

Table 1 describes the parameters in the SaltzmanWAISD05.xls file.

Table 1. Parameters in the SaltzmanWAISD05.xls File

Parameter	Description
Depth	Sample depth, in meters
C2H6	Ethane
C3H8	Propane
n-C4H10	N-butane
COS	Carbonyl sulfide
CS2	Carbon disulfide
CH3Cl	Methyl chloride
CH3Br	Methyl bromide
CH3CN	Acetonitrile
CFC12	Chlorofluorocarbon-12
err	Error is +/- 1 standard deviation

 

Sample Data Record

depth	ethane	err	propane	err	n-butane	err	COS	err	CS2	err	CH3Cl	err	CH3Br	err	CH3CN	err	CFC12	err
71.7	1490.0	12.3	793.1	14.3	285.4	4.0	572.1	16.6	11.0	1.4	579.5	24.7	7.4	0.6	14.8	7.5	433.7	10.6

Quality Assessment

Mixing ratios could reflect the impact of analytical or sampling artifacts in addition to real temporal variations in atmospheric levels of these trace gases. Based on prior studies (Aydin et al., 2008; Saltzman et al., 2009; Williams et al., 2007), it is expected that Antarctic ice cores in general preserve a real atmospheric record of CH3Cl, CH3Br, COS, CS2, and CFC-12. However, there are no prior published ice core records for any of the other compounds reported here. It is not recommended that the light alkane and CH3CN data be interpreted as paleo-atmospheric gas records.

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The data set is a total of 36 KB.

Software and Tools

Data are accessible using standard spreadsheet software.

Related Data Collections

• Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br)
• Antarctic Ice Cores: Methyl Chloride and Methyl Bromide
• WAISCORES Data

4. Data Acquisition and Processing

Theory of Measurements

The analyses were conducted in a gas chromatography/mass spectrometry system at the University of California, Irvine. Details of the ice extraction and analytical methods can be found in Aydin et al., 2007.

5. References and Related Publications

Aydin, M., M. B. Williams, C. Tatum, and E. S. Saltzman. 2008. Carbonyl Sulfide in Air Extracted from a South Pole Ice Core: a 2,000-Year Record. Atmos. Chem. Phys., 8, 7533-7542.

Aydin, M., M. B. Williams, and E. S. Saltzman. 2007. Feasibility of Reconstructing Paleoatmospheric Records of Selected Alkanes, Methyl Halides, and Sulfur Gases from Greenland Ice Cores. J. Geophys. Res., 112, D07312, doi:10.1029/2006JD008027.

Saltzman, E. S., M. Aydin, C. Tatum, and M. B. Williams. 2008. 2,000-Year Record of Atmospheric Methyl Bromide from a South Pole Ice Core. J. Geophys. Res., 113, D05304, doi:10.1029/2007JD008919.

Williams, M. B., M. Aydin, C. Tatum, and E. S. Saltzman. 2007. A 2000-Year Atmospheric History of Methyl Chloride from a South Pole Ice Core: Evidence for Climate-Controlled Variability. Geophys. Res. Lett., 34, L07811, doi:10.1029/2006GL029142.

Table 2 lists related documents that are available on the NSIDC Web site.

Table 2. Related Documents

Document	Description	URL
AGDC Web site	Data Center Web site	http://nsidc.org/agdc/
WAIS Divide Ice Core Project	WAISCORES Project Web site	http://www.waisdivide.unh.edu/

6. Document Information

Acronyms

The acronyms used in this document are listed in Table 3. Definitions of chemical symbols are listed in Table 1, above.

Table 3. Acronyms and Abbreviations

Acronym	Description
FTP	File Transfer Protocol
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator
WAISCORES	West Antarctic Ice Sheet Ice Cores
XLS	Microsoft Excel file extension

Document Creation Date

15 July, 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0412_saltzman/index.html