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This data set contains measurements of impurities and ions in three polar ice cores: the Vostok 5G ice core and the Byrd ice core from Antarctica, and the Greenland Ice Sheet Project 2 (GISP2) D core. Parameters include sample depth, grain size, ion concentration, and ice core impurity information. Measurements were made using Ion Chromatography (IC), optical microscopy, and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM/EDS).
Data are available via FTP in Microsoft Excel (.xls)and Microsoft Word (.doc) formats.
We kindly request that you cite the use of this data set in a publication using the following citation example. 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.
Baker, I. and R. Obbard. 2010. Microstructural Location and Composition of Impurities in Polar Ice Cores. Boulder, Colorado, USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5DF6P5P.
|Data format||Data are in Microsoft Excel (.xls) format, with additional notes in Microsoft Word (.doc) format.|
|Spatial coverage and resolution||
The data are from three ice cores: the Vostok 5G and the Byrd ice cores from Antarctica, and the Greenland Ice Sheet Project 2 (GISP2) D core.The geographical locations are as follows:
|Temporal coverage and resolution||Data were processed between 1995 and 2005.|
|File naming convention||GISP2_Selected_Ions.xls
|File size||Files range in size from 20 KB to 272 KB|
|Parameter(s)||Sample Depth in meters (m)
Grain Size (area), in square millimeters (mm^2)
Ion Concentration (Na, NH4, K, Mg, Ca, Cl, NO3, SO4), in parts per billion (ppb)
Ice Core Impurities (concentration of ions and elements in impurities)
|Procedures for obtaining data||Data are available via FTP.|
Dr. Ian Baker
Thayer School of Engineering
8000 Cummings Hall
Hanover, NH 03755
Dr. Rachel Obbard
Thayer School of Engineering
8000 Cummings Hall
Hanover, NH 03755
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
This research was supported by NSF OPP grants 0440523 and 09980379.
Data are in Microsoft Excel (.xls) format.
Data are available on the FTP site in the ftp://sidads.colorado.edu/pub/DATASETS/AGDC/baker_nsidc_0436/ directory. Within this directory, there are 5 Microsoft Excel (.xls) spreadsheets, and one Microsoft Word (.doc) file. The contents of these data files are described in Table 1.
|GISP2_&_Byrd_Core_Impurity_Data.xls||This file contains information on the location of the most prevalent elements found in impurities in the GISP-2 D and Byrd cores. Note that hydrogen and nitrogen are undetectable by the EDS (too light) and oxygen is ubiquitous (found in every spectra) and hence not analyzed|
|GISP2_Impurities_Inclusions.xls||This file contains data on elements and ions identified in ice core impurities. Measurements were made using Ion Chromatography (IC), optical microscopy, and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM/EDS).|
|GISP2_Selected_Ions.xls||This file contains measurements of ions (Na, NH4, K, Mg, Ca, Cl, NO3, SO4) in samples from the Vostok 5G ice core.|
|Vostok_5G_ Grain_Size_Linear_Intercept.xls||This file contains grain size measurements made using the linear intercept method.|
|Vostok_5G_ Grain_Size.xls||This file contains grain size area measurements, made using optical microscopy.|
|Vostok_5G_Grain_Size_Notes.doc||This file contains observation notes related to the samples used for grain size measurement.|
Files are named according to the following convention and as described in Table 2:
|IceCore||Name of ice core:
|.xls||Microsoft Excel file extension|
Example: GISP2_Selected_Ions.xls contains ion chromatography data for the GISP2 D Ice Core.
The files range in size from 20 KB to 272 KB.
The data are from three ice cores, the Vostok 5G and the Byrd ice cores from Antarctica, and the Greenland Ice Sheet Project 2 (GISP2) D core.The geographical locations are as follows:
Southernmost Latitude: 80°01'S
Northernmost Latitude: 80°01'S
Westernmost Longitude: 119°31'W
Easternmost Longitude: 119°31'W
Southernmost Latitude: 72°28'S
Northernmost Latitude: 72°28'S
Westernmost Longitude: 106°48'E
Easternmost Longitude: 106°48'E
Southernmost Latitude: 72°35'N
Northernmost Latitude: 72°35'N
Westernmost Longitude: 38°28'W
Easternmost Longitude: 38°28'W
Data were collected during laboratory experiments and observations, conducted from 1995 to 2005.
Parameters include sample depth (m), grain size (mm^2), ion concentration (ppb), and ice core impurity information (ppb).
|Sample Depth||Sample Depth, in meters|
|Grain Size||Grain size measurements in square millimeters (mm^2), measured using optical microscopy and the linear intercept method|
|Impurities||Elements and ions in ice core impurities|
|Ion Concentration||Ion concentration for Na, NH4, K, Mg, Ca, Cl, NO3, SO4, in ppb|
|Ratio of Impurity Counts by Depth to the Number of Spectra Collected at That Depth Normalized to Cl|
|SEM/EDS OBSERVATIONS||OPTICAL MICROSCOPY|
|SAMPLE||DATA||Impurity Ion Concentration (ppb)||Elements in||Relaxation Figures|
|DEPTH (m)||DEPTH (m)||Age (yrBP)||SO4||NO3||Cl||Ca||Mg||K||NH4||Na||GB Filaments||Dust found||vapor fig||GBPores||#/mmthick||Area (mm^2)||Total Area||COMMENTS|
|GISP2 Ion Chromatography Data (ppb)|
|Ion||grain interior||grain boundary||IDL*|
|V3311_A Measured and Marked|
|Linear Intercept Method|
|Actual (mm)||Scale (mm)|
Data are available via FTP.
The total data volume is approximately 600 KB.
Data are accessible using standard spreadsheet software.
Ion chromatography data were acquired using Dionex guard and separator columns for anions and cations.
Scanning Electron Microscope (SEM) data are from the Dartmouth Environmental Scanning Electron Microscope (ESEM): JEOL 5310LV.
Energy Dispersive Spectroscopy (EDS) data were acquired using a germanium detector with aluminum coated polyimide window.
Additional notes on methods are available in each data file, and in the related references, listed below and in the data files.
Data acquisition methods are described in detail in Obbard and Baker, 2007, Cullen and Baker, 2000 and 2001, and Baker et. al., 2003. See the references listed below.
Ice core samples were obtained from the National Ice Core Laboratory (NICL) in Denver, Colorado, USA.
Alley, R. B and G. A. Woods, 1996. Impurity influence on normal grain growth in the GISP2 ice core, Greenland. J. Glaciol., 42(141), 255-260.
Baker, I., D. l Iliescu, R. Obbard, H. Chang, B. N. Bostick,and C. P. Daghlian. 2006. Microstructural characterization of ice cores, Annals of Glaciology, vol. 42, p. 441.
Baker, I., R. W. Obbard, D. Iliescu and D. Meese. 2007. Microstructural Characterization of Firn. Hydrological Processes, vol. 21, no. 12, p. 1624.
Baker, I., R. W. Obbard, D. Iliescu and D. Meese. 2006. Microstructural Characterization of Firn. Proceedings of the 46th Eastern Snow Conference, Bibliography: p. 211.
Buck, C. F., P. A. Mayewski, M. J. Spencer, S. Whitlow, M. S. Twickler, and D. Barrett. 1992. Determination of major ions in snow and ice cores by ion chromatography. Journal of Chromatography A, Volume 594, Issues 1-2, 6 March, Pages 225-228, doi: 10.1016/0021-9673(92)80334-Q.
Cullen, D. C. 2002. The Structure and Chemistry of Polar Glacier Ice. PhD Thesis, Thayer School of Engineering, Dartmouth College, Hanover, NH.
Cullen, D. C. and I. Baker. 2000. Correspondence. The Chemistry of Grain Boundaries in Greenland Ice. J. Glaciology, 46(155), 703-706.
Cullen D. C. and I. Baker. 2001. Observations of Impurities in Ice. Microsc. Res. Tech., 55(3), 198-207.
The Greenland Summit Ice Cores CD-ROM. 1997. Available from the ARCSS data archive at NCAR and at the WDC for Paleoclimatology, NOAA-NGDC. http://data.eol.ucar.edu/codiac/dss/id=106.arcss008
Gow, A. J., D. A. Meese, R. B. Alley, J. J. Fitzpatrick, S. Anandakrishnan, G. A. Woods and B. C. Elder. 1997. Physical and structural properties of the Greenland Ice Sheet Project 2 ice core: A review. J. Geophys. Res., 102(C12), 26559-26575.
Iliescu, D. and I. Baker. 2008. Effects of Impurities and their Redistribution during Recrystallization in Ice Crystals, Journal of Glaciology, vol. 54, p. 362.
Obbard, R., I. Baker and D. Iliescu. 2006. Grain Boundary Grooving in Ice in a Scanning Electron Microscope, Journal of Glaciology, vol. 52, no. 176, p. 169.
Obbard, R., I. Baker and K. Sieg. 2007. Using Electron Backscatter Diffraction Patterns to Examine Recrystallization in Polar Ice Sheets, Journal of Glaciology, vol. 52, no. 179, p. 546.
Obbard, R. and I. Baker. 2007. The Microstructure of Meteoric Ice from Vostok, Antarctica, Journal of Glaciology, vol. 53, no. 180, p. 41.
The following related documents are available on the NSIDC Web site:
|Antarctic Glaciological Data Center (AGDC)||Data Center Web site||http://nsidc.org/agdc/|
|AGDC: Ice Core Records||Related Data Sets||http://nsidc.org/agdc/data/paleoclimate.html|
The following acronyms are used in this document.
|AGDC||Antarctic Glaciological Data Center|
|DOC||Microsoft Word Document File Extension|
|FTP||File Transfer Protocol|
|GISP2||Greenland Ice Sheet Project 2|
|IDL||Instrument Detection Limit|
|NSIDC||National Snow and Ice Data Center|
|SEM/EDS||Scanning Electron Microscope/Energy Dispersive Spectroscopy|
|URL||Uniform Resource Locator|
|XLS||Microsoft Excel File Extension|
21 January 2010