Nitrogen and Oxygen Gas Isotopes in the Siple Dome, Antarctica and GISP2 Ice Cores

Summary

This data set consists of Gas-isotopic data from the Siple Dome and Greenland Ice Sheet Project 2 (GISP2) ice cores covering roughly the last 100,000 years (100 ka), consisting of d15N (15N/14N) of N2, d18O (18O/16O) of O2, dO2/N2, and dAr/N2. Derived parameters include past changes in the Dole Effect and the fractionation that causes the Dole Effect.

Data are available via FTP as ASCII text files (.txt) and Microsoft Excel files (.xls).

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

Severinghaus, J. 2009. Nitrogen and oxygen gas isotopes in the Siple Dome and GISP2 ice cores, Antarctica. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N55X26V0.

Overview Table

Category	Description
Data format	ACSII text file (.txt), Microsoft Excel file (.xls).
Spatial coverage and resolution	Southernmost Latitude:80°01'S Northernmost Latitude: 80°01'S Westernmost Longitude: 119°32'W Easternmost Longitude: 119°32'W
Temporal coverage and resolution	Cores in this collection were obtained at Siple Dome, West Antarctica (81.65°S, 148.81°W) during the 1994/1995 field season, and at Greenland Ice Sheet Project 2 (GISP2) ice core in Greenland.
File naming convention	filename Data_Severinghaus_etal2009.txt
File size	Files in this data set range in size from 1.8 MB to 2.3 MB, for a total of 4.1 MB.
Parameter(s)	Parameters are measurements of d18Oatm of Oxygen, d15Nof Nitrogen, dO2/N2, and dAr/N2
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. Jeffrey Severinghaus
Scripps Institution of Oceanograpy
University of California, San Diego
9500 Gilman Drive
La Jolla CA, 92093
Mail Code: 0244

Technical Contact

Acknowledgements

This research was supported by NSF OPP grant 0440975 .

2. Detailed Data Description

Format

Data are available as an ASCII text file (.txt) and a Microsoft Excel file (.xls).

File and Directory Structure

Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/severinghaus_nsidc_0407/ directory.

File Naming Convention

Files are named according to the following convention:

Data_Severinghaus_etal2009.txt

File Size

Files in this data set range in size from 1.8 MB to2.3 MB, for a total of 4.1 MB.

Spatial Coverage

Data were collected at Siple Dome, Antarctica and the Greenland Ice Sheet Project 2 (GISP2) ice core, Greenland.

Southernmost Latitude: 80°01'S
Northernmost Latitude: 80°01'S
Westernmost Longitude: 119°32'W
Easternmost Longitude: 119°32'W

Spatial Coverage Map

Temporal Coverage

Cores in this collection were obtained at Siple Dome, West Antarctica (81.65°S, 148.81°W) during the 1994/1995 field season, and at Greenland Ice Sheet Project 2 (GISP2) ice core in Greenland (1998).

Parameter or Variable

Parameters are measurements of d18Oatm of Oxygen, d15Nof Nitrogen, dO2/N2, and dAr/N2

Sample Data Record

The following example shows sample data from the Data_Severinghaus_etal2009.txt.
Siple Dome ¹⁸O of O² :

rep	d15N	d18O	dO2/N2	dAr/N2
a	0.204	0.445	-13.44	-6.56
a	0.191	0.438	-13.02	-6.26
a	0.2	0.428	-10.39	-4.77
a	0.202	0.431	-11.1	-4.98
a	0.196	0.405	-9.02	-4.74
a	0.193	0.4	-11.04	-5.61
a	0.196	0.43	-13.4	-7.15
a	0.207	0.437	-13.9	-7.5
a	0.206	0.431	-8.43	-3.26
a	0.191	0.39	-7.81	-3.39

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total volume of the data set is less than 4.1 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

Delta18Oatm is a useful variable for correlating ice cores, and for inferring information about past climate and ice extent. At any given time, delta18O is approximately constant throughout the atmosphere, but this value varies over time due to changes in the hydrologic cycle, ice sheet volume, and worldwide patterns of plant growth.

Sensor or Instrument Description

The nitrogen and oxygen gas isotopes were analyzed on a ThermoFinnigan MAT Delta Plus XP isotope ratio mass spectrometer with 8 Faraday cups for simultaneous integration of mass/charge 28, 29, 32, 34, and 40 ion beams.

Data Acquisition Methods

The nitrogen and oxygen gas isotopes were analyzed using cores obtained at Siple Dome, West Antarctica (81.65°S, 148.81°W) during the 1994/1995 field season, and Greenland Ice Sheet Project 2 (GISP2) ice core in Greenland.

5. References and Related Publications

Severinghaus, J.P., R. Beaudette, M. Headly, K. Taylor, E.J. Brook, Oxygen-18 of O2 Records the Impact of Abrupt Climate Change on the Terrestrial Biosphere, Science 324, 1431-1434 (2009). doi: 10.1126/science.1169473

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
ka	one thousand years
d15N	(15N/14N) of N2 (nitrogen)
d18O	(18O/16O) of O2 (oxygen)
dO2/N2	delta oxygen and nitrogen
dAr/N2	delta argon and nitrogen
MB	megabyte

Document Creation Date

01 July 2009

Document URL

http://nsidc.org/data/docs/agdc/nsidc0407_severinghaus/index.html