This data set contains sub-annually resolved ice core chemistry data from various sites on the Antarctic Ice Sheet during the US International Trans-Antarctic Scientific Expedition (US ITASE) deployments. Researchers conducted experiments approximately every 30 - 300 km looking for clues representing climatic conditions over the past 200-1000+ years. Ice cores obtained for the glaciochemical component of the US ITASE research were analyzed for soluble major ion content and in some cases trace elements. Extreme events, such as volcanic eruptions, provide absolute age horizons within each core that are easily identified in chemical profiles. Our chemical analysis is also useful for quantifying anthropogenic impact, biogeochemical cycling, and for reconstructing past atmospheric circulation patterns.
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US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data, Version 2
New ice cores and surface snow samples were added. Some of the pre-existing core samples were re-run. Some of the pre-existing cores were re-dated. New data was added (ions, trace elements, isotopes, density, SWE).
Geographic Coverage
Spatial Coverage: |
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---|---|
Spatial Resolution: | Not Specified |
Temporal Coverage: |
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Temporal Resolution: | Not specified |
Parameter(s): |
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Platform(s) | GROUND STATIONS, GROUND-BASED OBSERVATIONS |
Sensor(s): | CORING DEVICES |
Data Format(s): |
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Version: | V2 |
Data Contributor(s): | Daniel Dixon, Paul Mayewski |
Metadata XML: | View Metadata Record |
Data Citation
As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.
Mayewski, P. A. and D. A. Dixon. 2013. US International Trans-Antarctic Scientific Expedition (US ITASE) Glaciochemical Data, Version 2. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N51V5BXR. [Date Accessed].Detailed Data Description
At each core/pit site, a 3-inch diameter (7.6 cm) ice core was drilled up to a depth of 120 m and sampling was taken between 50 m and 70 m. Surface snow samples were collected every 10 - 40 km. High-resolution chemical analysis (up to 75 measurements per meter) was used to define each core-chemistry year based on peaks in Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42- (sea salt and non-sea salt), and CH3SO3- (methyl sulfonate), and in some cases trace elements.
The ions, Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42-, and CH3SO3-, either individually or in combinations, indicate many different processes occurring in, around, or over Antarctica. By looking at these ion concentrations down ice cores, researchers can obtain accurately dated, sub-annual records of Antarctic meteorological and glaciochemical processes hundreds, or sometimes thousands of years into the past.
Data are provided in the following formats:
- Comma-separated Value (CSV)
- Microsoft Excel Spreadsheet (.xlsx)
- Tag Image File (.tif).
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/nsidc0273_dixon_v2/
directory. Within this directory, there are 66 files with three different file formats. The file formats dictate the type of data in that file. For example:
- Chemistry data are in Comma-separated Value (CSV) format
- Accumulation data are in a Microsoft Excel Spreadsheet (.xlsx) format
- Core location map is in Tag Image File (.tif) format.
File names correspond to the year each core was extracted, along with individual core/pit locations where the data were collected.
Central West Antarctic Data Files
This section explains the file naming convention used for the Central West Antarctic data files.
Example File Name: CWA_a_2013.csv
CWA_x_2013.csv
Refer to Table 1 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
CWA |
Central West Antarctic |
x |
a = 1st core of the field season d = 4th core of the field season |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Ross Ice Drainage System Data Files
This section explains the file naming convention used for the Ross Ice Drainage System data files.
Example File Name: RIDS95A_2013.csv
RIDS95x_2013.csv
Refer to Table 2 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
RIDS |
Ross Ice Drainage System |
95 |
Data obtained in 1995 |
x |
A = 1st core of the field season B = 2nd core of the field season C = 3rd core of the field season |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Kamb Ice Stream Data Files
This section explains the file naming convention used for the Kamb Ice Stream data files. Note: This ice stream use to be called Ice Stream C.
Example File Name: UpC_2013.csv
Refer to Table 3 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
UpC |
Kamb Ice Stream |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Siple Dome Data Files
This section explains the file naming convention used for the Siple Dome data files.
Example File Name: SDM1994_2013.csv
Refer to Table 4 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
SDM |
Siple Dome |
1994 |
Data obtained in 1994 |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
South Pole Data Files
This section explains the file naming convention used for the South Pole data files.
Example File Name: SouthPole1995_2013.csv
Refer to Table 5 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
SouthPole |
South Pole |
1995 |
Data obtained in 1995 |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
US_ITASE Data Files
This section explains the file naming convention used for the US_ITASE data files.
Example File Name: US_ITASE-00-1_2013.csv
US_ITASE-xx-y_2013.csv
Refer to Table 6 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
xx |
Year the core was drilled. For example, 99 = 1999-2000 field season; 00 = 2000-2001 field season; etc. |
y |
Core number for each season. For example, 00-1 = 1st core drilled during the 2000-2001 field season; 01-5 = 5th core of the 2001-2002 field season; etc. |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Example File Name: US_ITASE_Core Info-SWE-Density_2013.xlsx
Refer to Table 7 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE_ |
US International Trans-Antarctic Scientific Expedition |
Core Info-SWE-Density |
This spreadsheet has three worksheets: US ITASE Core Locations - contains various information for each ice core such as location, elevation, and depth US ITASE SWE - contains annual accumulation data in snow water equivalent units US ITASE Density - ice core density profiles calculated from field measurements |
2013 |
Year the files were updated |
.xlsx |
Microsoft Excel Spreadsheet Format |
Example File Name: US_ITASE_Core Map_2013.tif
Refer to Table 8 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE_Core |
US International Trans-Antarctic Scientific Expedition |
Map |
US ITASE Snow Core/Pit Site Map |
2013 |
Year the files were updated |
.tif |
Tag Image File Format |
Example File Name: US_ITASE_Surface Snow_02_IC_2013.csv
US_ITASE_Surface Snow_xx_IC_2013.csv
Refer to Table 9 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
Surface Snow |
Indicates that this file contains various data types from the surface snow samples/sites |
xx |
Field season in which the surface snow sample was collected. For example, 02 = the 2002-2003 field season |
IC |
Surface snow major-ion data measured using an Ion Chromatograph |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Example File Name: US_ITASE_Surface Snow_02_ICPMS_2013.csv
US_ITASE_Surface Snow_xx_ICPMS_2013.csv
Refer to Table 10 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
Surface Snow |
Indicates that this file contains various data types from the surface snow samples/sites |
xx |
Field season in which the surface snow sample was collected. For example, 02 = the 2002-2003 field season |
ICPMS |
Surface snow trace-element data measured using an Inductively Coupled Plasma Mass Spectrometer |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Example File Name: US_ITASE_Surface Snow_02_Physical Parameters_2013.csv
US_ITASE_Surface Snow_xx_Physical Parameters_2013.csv
Refer to Table 11 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
Surface Snow |
Indicates that this file contains various data types from the surface snow samples/sites |
xx |
Field season in which the surface snow sample was collected. For example, 02 = the 2002-2003 field season. |
Physical Parameters |
Various physical and isotopic surface snow data types. See Dixon et al., 2013 for detailed info. |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Example File Name: US_ITASE-02-1_ICPMS_2013.csv
US_ITASE-xx-y_ICPMS_2013.csv
Refer to Table 12 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
xx |
Field season in which the surface snow sample was collected. For example, 00 = the 2000-2001 field season |
y |
Core number for each season. For example, 00-1 = 1st core drilled during the 2000-2001 field season; 01-5 = 5th core of the 2001-2002 field season; etc. |
ICPMS |
Surface snow trace-element data measured using an Inductively Coupled Plasma Mass Spectrometer |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Example File Name: US_ITASE-02_BYRD_2013.csv
Refer to Table 13 for the valid values for the file name variables listed above.
Where:
Variable | Description |
---|---|
US_ITASE |
US International Trans-Antarctic Scientific Expedition |
xx |
Field season in which the surface snow sample was collected. For example, 00 = the 2000-2001 field season |
BYRD |
Test core drilled at Byrd Station. See core info table for more info. |
2013 |
Year the files were updated |
.csv |
Comma-separated Value Format |
Files sizes range from 16 KB to 2693 KB.
The entire data set is approximately 8.5 MB.
Data were collected on the Western Antarctic Ice Sheet (WAIS) and the Eastern Antarctic Ice Sheet (EAIS). For exact core/pit locations, see the US ITASE Snow Core/Pit Site Map.
Southernmost Latitude: -90.0° S
Northernmost Latitude: -77.68° S
Westernmost Longitude: -76.1° W
Easternmost Longitude: 152.37° E
These US ITASE data were collected during the Antarctic summer from 1999 to 2008. See the core info table for more detailed info. These data were used for reconstruction of sub-annual scale climate variability and changes in the chemistry of the atmosphere over the last 200+ years. Refer to Figure 1.
- Ion Concentrations of Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42- (sea salt and non-sea salt), and CH3SO3- (methyl sulfonate) (µg/L)
- Trace Elements of Sr, Cd, Sb, Cs, Ba, La, Ce, Pr, Nd, Pb, Bi, As, Tl, Ti, V, Cr, Mn, Co, Cu, Zn, Li (ng/L)
Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, U (pg/L)
Al, S, Ca, Fe, Na, Mg, K (µg/L) - Snow Water Equivalent (cm)
Parameter Description
The researchers analyzed a glaciochemical series of ion concentrations including Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42- (sea salt and non-sea salt), and CH3SO3-(methyl sulfonate). They studied annual accumulation rates by using Snow Water Equivalents (SWE). They reported concentrations of the ions Na+, Cl-, SO42-, Ca2+, Mg2+, K+, NH4+, NO3- (sea salt and non-sea salt), and CH3SO3- (methyl sulfonate), and in some cases trace elements (Sr, Cd, Sb, Cs, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Pb, Bi, U, As, Tl, Al, S, Ca, Ti, V, Cr, Mn, Fe, Co, Cu, Zn, Li, Na, Mg, K). The ionic composition of polar ice cores provides a stratigraphic tool for relative dating that can be extremely effective on the Western Antarctic Ice Sheet (WAIS). It also allows researchers to document changes in chemical species source emissions and to characterize the major atmospheric circulation systems affecting WAIS. Refer to Tables 14 and 15 for a listing of the Periodic Element Names.
Element Symbol
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Element Name
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---|---|
Na+
|
Sodium Ion
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Ca2+
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Calcium Ion
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Mg2+
|
Magnesium Ion
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K+
|
Potassium Ion
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NH4+
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Ammonium Ion
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Cl-
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Chlorine Ion
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NO3-
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Nitrate Ion
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SO42-
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Sulfate Ion
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CH3SO3-
|
Methyl sulfonate
|
Element Symbol
|
Element Name
|
---|---|
Sr
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Strontium
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Cd
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Cadmium
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Sb
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Antimony
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Cs
|
Caesium
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Ba
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Barium
|
La
|
Lanthanum
|
Ce
|
Cerium
|
Pr
|
Praseodymium
|
Nd
|
Neodymium
|
Sm
|
Samarium
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Eu
|
Europium
|
Gd
|
Gadolinium
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Tb
|
Terbium
|
Dy
|
Dysprosium
|
Ho
|
Holmium
|
Er
|
Erbium
|
Tm
|
Thulium
|
Yb
|
Ytterbium
|
Lu
|
Lutetium
|
Pb
|
Lead
|
Bi
|
Bismuth
|
U
|
Uranium
|
As
|
Arsenic
|
TI
|
Thallium
|
AI
|
Thallium
|
S
|
Sulfur
|
CA
|
Calcium
|
Ti
|
Titanium
|
V
|
Vanadium
|
Cr
|
Chromium
|
Mn
|
Manganese
|
Fe
|
Iron
|
Co
|
Iron
|
Cu
|
Copper
|
Zn
|
Zinc
|
Li
|
Lithium
|
Na
|
Sodium
|
Mg
|
Magnesium
|
K
|
Potassium
|
Sample Data Record
Figure 1 is a sample record of the SouthPole1995_2013.csv
data file. There are several different types of data files in this data set.

Software and Tools
The user will need a text editor and spreadsheet software in order to view the data.
Data Acquisition and Processing
The US ITASE field season involved drilling numerous ice cores and collecting snow pit samples along several traverse segments. Refer to Figure 2. At each core/pit site, a 3-inch diameter (7.6 cm) ice core was drilled up to a depth of 120 m and sampling was taken between 50 m and 70 m. Workers wearing non-particulating suits, polyethylene gloves, and particle masks sampled snow pits and processed ice cores. Samples were stored in precleaned polyethylene containers and stored below -20° C until melting immediately prior to chemical analysis. Major ions were analyzed using ion chromatography. High-resolution chemical analysis requiring 30 to 50 measurements per meter was used to define each core-chemistry year based on peaks in Na+, Ca2+, Mg2+, K+, NH4+, Cl-, NO3-, SO42- (sea salt and non-sea salt), and CH3SO3- (methyl sulfonate).

Data were generated using the University of Maine's continuous melter (UMCoM) system, an Ion Chromatograph (IC) and an Inductively Coupled Plasma Mass Spectrometer (ICPMS). The data consist of dissolved major ion concentrations and total elemental concentrations at sub-annual resolution. The UMCoM system is housed in a dedicated clean room with HEPA filtered air. Standard clean room procedures are employed during melting. A Wagenbach-style melter head was modified to include a pure Nickel disk that can be easily dismantled for thorough cleaning. The system allows ice and firn to melt without wicking the meltwater into unmelted core. Unlike continuous-flow melter systems in which the meltwater is directly channeled to online instruments for analyses, the UMCoM system collects discrete samples under ultra-clean conditions.
References and Related Publications
Contacts and Acknowledgments
Paul A Mayewski
Climate Change Institute
Global Science Center, University of Maine
Orono, ME, USA
Daniel A Dixon
Climate Change Institute
Global Science Center, University of Maine
Orono, ME, USA
This grant was supported by the National Science Foundation (NSF) Office of Polar Programs (OPP) award OPP-9725057 and OPP-0837883.
Document Information
DOCUMENT CREATION DATE
July 2013
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