Twenty-Three Century-Scale Ice Core Records of Hydrogen Peroxide (H₂O₂) from West Antarctica

Summary

This data set contains sub-annually resolved concentrations of hydrogen peroxide (H₂O₂), snow, firn and ice from 23 sites on the West Antarctic Ice Sheet (WAIS. Data were obtained from 2000 to 2003 during the US International Trans-Antarctic Scientific Expedition (US ITASE) deployments. Cores were drilled approximately every 100-300 kilometers down to depths of up to 120 meters. H₂O₂ was measured in snow, firn, and ice using a fluorescence detection method either in situ after sampling or in the lab 9-12 months after sample collection. Depending on local accumulation rate, up to 500 year long records were obtained from the WAIS region (76-90ºS / 84-124ºW). Core H₂O₂ concentrations are reported in parts per billion by weight (ppbw) as a function of decimal year.

Data are available via FTP as ASCII text files (.txt).

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, publisher: NSIDC, and digital media

Bales, R. , M. Frey, J. McConnell. 2009. Twenty-three century-scale ice core records of hydrogen peroxide (H₂O₂) from West Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5TM7826.

Overview Table

Category	Description
Data format	ACSII text files (.txt)
Spatial coverage and resolution	Southernmost Latitude: 90ºS Northernmost Latitude: 76 °S Westernmost Longitude: 124°W Easternmost Longitude: 84°W
Temporal coverage and resolution	20 November 2000 to 15 January 2003, Antarctic summers only.
File naming convention	filename ITYY_i.txt
File size	Files in this data set range in size from 2 KB to 779 KB for a total of 4.4 MB
Parameter(s)	core depth, year,hydrogen peroxide concentration ın snow, firn and ice
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. Roger Bales
University of California - Merced
School of Engineering
5200 North Lake Rd.
Merced, California 95343

Dr. Markus Frey
University of California - Merced
School of Engineering
5200 North Lake Rd.
Merced, California 95343

Dr. Joesph McConnell
Desert Research Institute
Division of Hydrological Sciences
2215 Raggio Parkway
Reno, Nevada 89512

Technical Contact

Acknowledgements

This research was supported by NSF OPP grant 9814810 .

2. Detailed Data Description

Format

Data are available as ASCII text files (.txt).

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/bales_nsidc_0392/ directory.
A subdirectory entitled ITASE_core_H2O2_NSIDC0392 contains 23 .txt files, a readme.txt file with site information, and a data set readme file in both ASCII text format and Microsoft Word format.

File Naming Convention

Files are named according to the following convention:

ITYY_i.txt

• filename ITYY_ii.txt contains site ID: for example: IT00_01.txt refers to ITASE 2000/01 site 1

README contains site information site ID, latitude, longitude, site elevation (m.a.m.s.l.), core bottom depth (m), core top depth (m)
Example: IT00_1 79.38308 111.22867 1791 105.560 1.000

File Size

Files in this data set range in size from2 KB to 779 KB, for a total of 4.4 MB.

Spatial Coverage

Data were collected along the United States International Trans Antarctic Scientific Expedition (US ITASE) traverse route.

Southernmost Latitude: 90 °S
Northernmost Latitude: 76 °S
Westernmost Longitude: 124°W
Easternmost Longitude: 84 °W

Spatial Coverage Map

The map above shows core locations along traverse routes of the U.S. portion of the International Trans-Antarctic Scientific Expedition (US ITASE).

Temporal Coverage

Data in this collection were obtained 20 November 2000 to 15 January 2003, Antarctic summers only.

Parameter or Variable

Table 1. Parameters in the Profile Data Files

Parameter
hydrogen peroxide concentration in snow/firn and ice as a function of years

Sample Data Record

The following example shows sample data from the ice core hydrogen peroxide (H₂O₂) measurements.

depth in meters	decimal year	H2O2 ppbw
1.13	1999.396	23.7
1.14	1999.375	26.5
1.15	1999.354	29.5
1.17	1999.333	32
1.18	1999.313	34.3
1.2	1999.292	36.6
1.21	1999.271	39
1.23	1999.25	42.1
1.24	1999.229	45.7
1.26	1999.208	49.9

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total volume of the data set is less than 4.4 MB.

Software and Tools

Data are accessible using standard spreadsheet software.

Related Data Collections

• Antarctic Glaciological Data Center (AGDC)

4. Data Acquisition and Processing

Theory of Measurements

3"-cores were drilled to a maximum of 120m at various WAIS locations under the U.S. ITASE program. A 3x3 cm cross section was sampled after each field season at National Ice Core Laboratory (NICL, Lakewood, CO) and shipped frozen to the laboratory at the University of Arizona.

Sensor or Instrument Description

A Continuous Flow Analysis (CFA) system: based on a steady sample flow combined with an immediate detection of the compound of interest. To obtain a continuous sample stream, the ice core (typically a subcore of 3x3 cm cross section) is melted continuously on a specially developed melt device where the sample is permanently drained off by a peristaltic pump and split into the analytical systems

Data Acquisition Methods

Cores were analyzed using a CFA system, with H₂O₂ being detected via fluorescence detection.

Limits of detection The limit of detection for hydrogen peroxide in snow, firn and ice was below 1 ppbw. Reported are 48 samples per year, which is equivalent to 0.2 to 0.9 cm depth resolution. However, the true depth resolution is determined by the measurement method and is about 2 cm in shallow firn and 1 cm in ice. More details on database development (experimental method, data processing) and discussion of the results are published in Frey et al., 2006.

5. References and Related Publications

Banta, J. R.,J. R. McConnell, M. M. Frey, et al. 2008. Spatial and temporal variability in snow accumulation at the West Antarctic Ice Sheet Divide over recent centuries. Journal of Geophysical Research-Atmospheres, 113 (D23): Art. No. D23102.

Frey, M. M., R. C. Bales, and J. R. McConnell. 2006. Climate sensitivity of the century-scale hydrogen peroxide (H₂O₂) record preserved in 23 ice cores from West Antarctica. Journal of Geophysical Research, 111(D21301), doi:10.1029/2005JD006816 .

Grannas, A. M., A. E. Jones, J. Dibb, et al. 2007. An overview of snow photochemistry: evidence, mechanisms and impacts. Atmospheric Chemistry and Physics. 7 (16): 4329-4373.

Miles, G. M., G. J. Marshall, J. R. McConnell, et al. 2008. Recent accumulation variability and change on the Antarctic Peninsula from the ERA40 reanalysis. International Journal of Climatology, 28 (11): 1409-1422.

Kirschvink, J. L., R. E. Kopp. 2008. Palaeoproterozoic ice houses and the evolution of oxygen-mediating enzymes: the case for a late origin of photosystem II. Philosophical Transactions of the Royal Society B-Biological Sciences, 363 (1504): 2755-2765.

Steig, E. J., P. A. Mayewski, D. Dixon, S. Kaspari, M. M. Frey, D. P. Schneider, S. A. Arcone, and G. S. Hamilton. 2005. High-resolution ice cores from US ITASE (West Antarctica): Development and Validation of chronologies and determination of precision and accuracy. Annals of Glaciology, 41:77–84.

Thomas, E. R., G. J. Marshall, and J. R. McConnell. 2008. A doubling in snow accumulation in the western Antarctic Peninsula since 1850. Geophysical Research Letters, 35 (1): Art. No. L01706.

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 2. Acronyms and Abbreviations

Acronym	Description
FTP	File Transfer Protocol
NSIDC	National Snow and Ice Data Center
URL	Uniform Resource Locator
WAIS	West Antarctic Ice Sheet
ITASE	International Trans-Antarctic Scientific Expedition
NICL	National Ice Core Lab
CFA	Continuous Flow Analysis
m.a.m.s.l.	meters above mean sea level
H2O2	hydrogen peroxide
NICL	National Ice Core Laboratory
ppbw	parts per billion by weight

Document Creation Date

23 April 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0392_bales/index.html