US ITASE Stable Isotope Data, Antarctica
Summary
This data set includes stable isotope measurements from snow pits, firn, and ice cores collected by the the US component of the International Trans-Antarctic Scientific Expedition ( ITASE). The ITASE program aims to collect and interpret a continental-wide array of environmental parameters assembled through the coordinated efforts of scientists from several nations.
These data were collected between 1999 and 2007. The data have been compiled into single files for each sampling site, though in some cases a file contains data from more than one ice core or snow pit. Each file in the data set includes deuterium/hydrogen (δD) and/or 18-oxygen/16-oxygen (δ18O) ratios, depths, and in some cases ice age or other information. Further details regarding the data are provided in each data file. Data are available via FTP in ASCII text format (.txt). Data were collected during five Antarctic field seasons from 1999 to 2007. Data from 1999 to 2002 are currently available. Data from 2003 to 2007 will be added in the future.
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. Users must also cite the appropriate published references, listed in the header information for each file.
Steig, E. J. 2009. US ITASE Stable Isotope Data, Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5NZ85MD.
Overview Table
| Category | Description |
|---|---|
| Data format | ASCII text (.txt) |
| Spatial coverage and resolution |
Southernmost Latitude: 90°S Northernmost Latitude: 65°S Westernmost Longitude: 130°W Easternmost Longitude: 85°W |
| Temporal coverage and resolution | Data were collected between 1999 and 2007. |
| File naming convention | ITASE_1999_1.txt ITASE_2000_1.txt |
| File size | File sizes range from 26 KB to 170 KB. |
| Parameter(s) | Oxygen Isotope (δ18O) Deuterium Isotopes (δD) Deuterium Excess (dxs) Ice Core Depth (meters) Ice Age |
| 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
Investigator(s)
Dr. Eric J. Steig
University of Washington
Department of Earth and Space Sciences
70 Johnson Hall City: Seattle Province or State: WA Postal Code:
Seattle, Washington
98195
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 grants 0440414 and 0196105.
2. Detailed Data Description
Format
Data are ASCII text format (.txt)
File and Directory Structure
Data are available on the FTP site
in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/steig_nsidc_0425/ directory.
Within this directory, there
are currently 15 ASCII text files containing data collected in 1999 to 2002. Additional data files for 2003 to 2007 will be added in the future.
File Naming Convention
Files are named according to the following convention and as described in Table 1. Additional information on the ice cores and snow pits is provided in the heading of each data file.
ITASE_YYYY_N.EXT
Where:
| Variable | Description |
|---|---|
| ITASE | Project name |
| YYYY | 4-digit year of data collection |
| N | Site number |
| EXT | File extension |
Example: ITASE_1999_1.txt: Contains data from the ITASE expedition collected in 1999.
File Size
File size ranges between 26 KB and 170 KB.
Spatial Coverage
Southernmost Latitude: 90°S
Northernmost Latitude: 65°S
Westernmost Longitude: 130°W
Easternmost Longitude: 85°W
Location Map
Figure 1. Map of ITASE Traverse Routes and Ice Core Locations
Image courtesy US ITASE Program
Temporal Coverage
Data were collected during five Antarctic field seasons from 1999 to 2007. Data from 1999 to 2002 are currently available. Data from 2003 to 2007 will be added in the future.
Temporal Resolution
Weekly to annual
Parameter or Variable
Parameters include oxygen and deuterium isotope ratios, and in some case ice age. Each data file contains additional details on the specific measurements and parameters in the file.
Parameter Description
| Parameter | Description |
|---|---|
| Depth | Top and bottom sample depth, in meters |
| Age | Sample age at top and bottom of sample, in calendar year |
| d180 | Stable oxygen ratio (18-oxygen/16-oxygen), in parts per million |
| delD | Deuterium ratio, in parts per million |
| dxs | Deuterium excess, in parts per million |
| Sample number | Sample identification number |
Sample Data Record
Example: ITASE_2000_1.txt
| Depth Top (m) | Depth Bottom (m) | Age Top (calendar year) | Age Bottom | d18O (per mil) | delD (per mil) | dxs (per mil) | Sample Number |
| 0 | 0.02 | 2001 | 2000.97 | -29.83 | -239.02 | -0.36 | ITASE2000C1_p442 |
Quality Assessment
Percent Isotope ratios are normalized on the V-SWOW / SLAP scale; precision is better than 0.1 per mill for d18O and better than 1 per mill for and delD.
3. Data Access and Tools
Data Access
Data are available via FTP.
Volume
The total volume of the data set will be approximately 4 MB, when all data files are available.
Software and Tools
Data are accessible using spreadsheet software.
Related Data Collections
- Ice Thickness and Internal Layer Depth Along the 2001 and 2002 US ITASE Traverses
- Late Holocene Climate Variability, Dry Valleys, Antarctica
- US International Trans Antarctic Scientific Expedition (US ITASE): GPR Profiles and Accumulation Mapping
- US International Trans Antarctic Scientific Expedition 400 MHz Subsurface Radar Profiles
- US International Trans Antarctic Scientific Expedition (US ITASE) Glaciochemical Data
4. Data Acquisition and Processing
Stable isotope concentrations (δ18O and δD) were analyzed by mass spectrometry, using CO2 equilibration and Cr reduction, in a laboratory at the University of Washington. For more information, see Steig, et al. 2005, and Schneider, et al., 2005, and the additional references cited below.
5. References and Related Publications
Steig E. J., P. A. Mayewski, D. A. Dixon, M. M. Frey, S. D. Kaspari, D. P. Schneider, S. A. Arcone, G. S. Hamilton, V. B. Spikes, M. Albert, D. Meese, A. J. Gow, C. A. Shuman, J. W. C. White, S. Sneed, J. Flaherty, and M. Wumkes. 2005. High-resolution ice cores from US ITASE (West Antarctica); development and validation of chronologies and estimate of precision and accuracy. Annals of Glaciology 41: 63-70.
Schneider D. P., E. J. Steig, and T. van Ommen. 2005. Interpretation of high resolution ice core stable isotope records from Antarctica: towards interannual climate reconstruction. Annals of Glaciology 541: 77-84.
Schneider D. P., and E. J. Steig. 2008. Ice cores record significant 1940s Antarctic warmth related to tropical climate variability. Proceedings of the National Academy of Sciences, 105(34): 12154-12158
Schneider D. P., E. J. Steig, T. J. van Omment, D. A. Dixon, P. A. Mayewski, J. M. Jones, and C. M. Bitz. 2006. Antarctic temperatures of the past two centuries from ice cores. Geophysical Research Letters 33, L16707, doi:10.1029/2006GL027057.
Jacobel R., B. Welch, E. J. Steig, and D. P. Schneider. 2005. Hercules Dome, Antarctica – an optimal site for deep ice core drilling. Journal of Geophysical Research – Earth Surface 110: F01015, doi:10.1029/2004JF000188.
Schneider D. P., and D. C. Noone. 2008. Spatial covariance of water isotopes in ice cores during 20th Century climate change. Journal of Geophysical Research, 112: D18105, doi:10.1029/2007JD008652.
Gregory, S., and D. Noone. 2008. Variability in the teleconnection between the El Nino-Southern Oscillation and West Antarctic climate. Journal of Geophysical Research, 113, D17110, doi:10.1029/2007JD009107.
Table 3 lists related Web pages:
| Document | Description | URL |
|---|---|---|
| Antarctic Glaciological Data Center (AGDC) | AGDC Web site | http://nsidc.org/agdc/ |
| United States International Trans Antarctic Scientific Expedition (US ITASE) | NSIDC US ITASE data Web site | http://nsidc.org/agdc/itase.html |
| Ice Reader | Ice Reader Web site | http://icereader.org |
| US International Trans- Antarctic Scientific Expedition | ITASE Project Web site | http://www2.umaine.edu/itase |
| University of Washington ITASE Web page | UW ITASE Web site | http://depts.washington.edu/itase |
6. Document Information
Acronyms
The acronyms used in this document are listed in Table 4.
| Acronym | Description |
|---|---|
| δD | Deuterium ratio |
| δ18O | Ratio of 18-Oxygen/16-Oxygen |
| FTP | File Transfer Protocol |
| ITASE | International Trans- Antarctic Scientific Expedition |
| NSIDC | National Snow and Ice Data Center |
| TXT | ASCII text file extension |
| URL | Uniform Resource Locator |
Document Creation Date
18 September 2009
Document URL
http://nsidc.org/data/docs/agdc/nsidc0425_steig/index.html
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