Reconstructions of ancient atmospheric CO2 variations help us better understand how the global carbon cycle and climate are linked. Here we compare CO2 variations on millennial time scales between 20,000 and 90,000 years with an Antarctic temperature proxy and records of abrupt climate change in the northern hemisphere. CO2 and Antarctic temperature are positively correlated over millennial-scale climate cycles, implying a strong connection to southern ocean processes. Evidence from marine sediment proxies indicates that CO2 rose most rapidly when North Atlantic Deep Water shoaled and stratification in the Southern Ocean was reduced. These increases in CO2 occurred during stadial (cold) periods in the northern hemisphere, several thousand years before abrupt warming events in Greenland. Data are available in Microsoft Excel format and are available via FTP.
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.
Ahn, Jinho and Edward Brook. 2007. Atmospheric CO2 Byrd Ice Core, Antarctica. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N58W3B80.
| Category | Description |
|---|---|
| Data format | Microsoft Excel |
| Spatial coverage and resolution |
Southernmost Latitude: 80.01° S Northernmost Latitude: 80.01° S Westernmost Longitude: 119.51° W Easternmost Longitude: 119.51° W Elevation - 1530 m |
| Temporal coverage and resolution | 90 to 20 ka |
| File naming convention | Ahn-Byrd-CO2-20-90ka.xls |
| File size | Approximately 45 KB. |
| Parameter(s) | Carbon dioxide (CO2) |
| Procedures for obtaining data | available via FTP |
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
Jinho Ahn
Department of Geosciences
Oregon State University
104 Wilkinson Hall
Corvallis, Oregon 97331 USA
Ed Brook
Department of Geosciences
Oregon State University
104 Wilkinson Hall
Corvallis, Oregon 97331 USA
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
This research was supported by National Science Foundation (NSF) Office of Polar Programs (OPP) grant 0337891and ATM 0602395 awarded to E. Brook and the Gary Comer Science and Education Foundation (PI: Prof. Edward J. Brook).
Data files are in Microsoft Excel format viewable with spreadsheet software and an Adobe Acrobat PDF.
Files are named according to the following convention.
| File name | File Size | Description |
Ahn-Byrd-CO2-20-90ka.xls |
45 KB | Microsoft Excel File |
Ahn-08-sci.pdf |
450 KB | associated .PDF file |
Ahn-08-sci-SOM.pdf |
700 KB | associated .PDF file |
Southernmost Latitude: 80.01° S
Northernmost Latitude: 80.01° S
Westernmost Longitude: 119.51° W
Easternmost Longitude: 119.51° W
The measured parameter is CO2 at various depths in the ice core.
Carbon dioxide (Co2): 201.79 parts per million by volume (ppmv) to 224.99 ppmv.
The data below are the first 10 data samples showing Byrd CO2 records.
BP= Before 1950 (GISP2 time scale)
Uncertainty is estimated from the standard deviation of the mean for 2~5 ice samples
Depth |
Blnier-01 age |
Ahn-08age |
mean CO2 |
# of replicates |
Uncertainty |
Ref. |
(m) |
GISP(ka BP) |
GISP(ka BP) |
(ppm) |
(ppm) |
||
1315.91 |
19.460 |
19.286 |
194.36 |
2 |
0.97 |
AB-08 |
1332.34 |
20.061 |
19.887 |
191.14 |
2 |
0.19 |
AB-08 |
1334.20 |
20.152 |
19.978 |
192.54 |
2 |
0.09 |
AB-08 |
1346.28 |
20.578 |
20.404 |
204.27 |
2 |
0.48 |
AB-08 |
1353.02 |
20.759 |
20.585 |
195.37 |
2 |
0.02 |
AB-08 |
1363.17 |
21.065 |
20.891 |
197.12 |
2 |
1.04 |
AB-08 |
1381.14 |
21.731 |
21.557 |
195.81 |
2 |
1.66 |
AB-08 |
1401.95 |
22.399 |
22.225 |
199.75 |
3 |
4.49 |
AB-08 |
1410.30 |
22.729 |
22.555 |
194.62 |
2 |
0.31 |
AB-08 |
1420.27 |
23.530 |
23.356 |
195.97 |
2 |
1.88 |
AB-08 |
The data set is approximately 45 KB.
Agilent 6890N Gas Chromatograph
The CO2 mixing ratio was measured with an Agilent 6890N Gas Chromatograph (GC) with flame ionization detector, with nickel catalyst conversion of CO2 to CH4 prior to measurement.
Ahn, Jinho and Ed Brook. 2007. Atmospheric CO2 and
climate from 65 to 30 ka B.P. Geophysical. Research Letters. 34, L10703,
doi:10.1029/2007GL029551.
Ahn, J. and Brook, E.J. Atmospheric CO2 and climate change on millennial time scales during the last glacial period, Science, 322, 83-85, doi: 10.1126/science.1160832 (2008)
The following acronyms and abbreviations are used in this document.
| FTP | File Transfer Protocol |
| NSIDC | National Snow and Ice Data Center |
| URL | Uniform Resource Locator |
October 2007
http://nsidc.org/data/docs/agdc/nsidc0314_ahn/index.html