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Microstructural Location and Composition of Impurities in Polar Ice Cores

Summary

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.

Citing These Data

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.

Overview Table

Category Description
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:

Byrd
Southernmost Latitude: 80°01'S
Northernmost Latitude: 80°01'S
Westernmost Longitude: 119°31'W
Easternmost Longitude: 119°31'W

Vostok 5G
Southernmost Latitude: 72°28'S
Northernmost Latitude: 72°28'S
Westernmost Longitude: 106°48'E
Easternmost Longitude: 106°48'E

GISP2 D
Southernmost Latitude: 72°35'N
Northernmost Latitude: 72°35'N
Westernmost Longitude: 38°28'W
Easternmost Longitude: 38°28'W

Temporal coverage and resolution Data were processed between 1995 and 2005.
File naming convention GISP2_Selected_Ions.xls
Vostok_5G_ Grain_Size.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.

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. Ian Baker
Thayer School of Engineering
Dartmouth College
8000 Cummings Hall
Hanover, NH 03755
USA

Dr. Rachel Obbard
Thayer School of Engineering
Dartmouth College
8000 Cummings Hall
Hanover, NH 03755
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 0440523 and 09980379.

2. Detailed Data Description

Format

Data are in Microsoft Excel (.xls) format.

File and Directory Structure

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.

Table 1. File Description
File Name Description
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.

File Naming Convention

Files are named according to the following convention and as described in Table 2:

IceCore_Parameter.xls

Where:

Table 2. File Naming Convention
Variable Description
IceCore Name of ice core:
  • GISP2: Greenland Ice Sheet Project 2 Ice Core D
  • Vostok_5G: Vostok 5G Ice Core
  • Byrd: Byrd Ice Core
Parameter Measurement type.
  • Impuritiesand Inclusions: Data on ions and elements in ice core impurities, determined by IC, optical microscopy, and SEM/EDS.
  • Grain Size: Grain size in area, determined by optical microscopy
  • Selected Ions: Ion measurements in parts per billion (ppb), determined by IC
.xls Microsoft Excel file extension

Example: GISP2_Selected_Ions.xls contains ion chromatography data for the GISP2 D Ice Core.

File Size

The files range in size from 20 KB to 272 KB.

Spatial Coverage

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:

Byrd
Southernmost Latitude: 80°01'S
Northernmost Latitude: 80°01'S
Westernmost Longitude: 119°31'W
Easternmost Longitude: 119°31'W

Vostok 5G
Southernmost Latitude: 72°28'S
Northernmost Latitude: 72°28'S
Westernmost Longitude: 106°48'E
Easternmost Longitude: 106°48'E

GISP2 D
Southernmost Latitude: 72°35'N
Northernmost Latitude: 72°35'N
Westernmost Longitude: 38°28'W
Easternmost Longitude: 38°28'W

Temporal Coverage

Data were collected during laboratory experiments and observations, conducted from 1995 to 2005.

Parameter or Variable

Parameters include sample depth (m), grain size (mm^2), ion concentration (ppb), and ice core impurity information (ppb).

Parameter Description

Table 3. Parameter Descriptions
Parameter Description
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

 

Sample Data Records

Sample Record from GISP2_&_Byrd_Core_Impurity_Data.xls
Ratio of Impurity Counts  by Depth to the Number of Spectra Collected at That Depth Normalized to Cl
  Depth
Ion 94 214 341 2750 2850 2950
Cl 0.187807814 0.173361059 0.153660939 0.164331838 0.156506512 0.164331838 1
Na 0.179271096 0.158914304 0.102440626 0.046951954 0 0.140855861 0.62843384
S 0.068293751 0.08668053 0.136587501 0.140855861 0.031301302 0.023475977 0.487194922

 

 

 
Sample Record from GISP2_Impurities_Inclusions.xls
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
94 94(3) 94 73.04 71.93 10.99 7.62 1.43 2.15 5.22 4.14              
150.10-150.13 146.466(1) 481 30.80 103.85 7.73 4.88 1.36 2.02 20.62 1.20 yes none  
249.0-249.03 246.466(1) 911 22.93 74.76 9.64 0.58 0.25 1.28 4.53 1.21         0.51 0.0101 0.0051 "black vf"


Sample Record from GISP2_Selected_Ions.xls
GISP2 Ion Chromatography Data (ppb)
Depth
Ion grain interior grain boundary IDL*
94 m 214m 341m 2750m 2850m 2950m 2950m
Na 950.57 13.62 29.03 38.16 14.78 67.35 158.21 10



Sample Record from Vostok_5G_Grain_Size.xls
V3311_A Measured and Marked
1 85.04
2 65.57

 

 

Sample Record from Vostok_5G_Grain_Size_Linear_Intercept.xls
Vostok 248m
Linear Intercept Method
Actual (mm) Scale (mm)
Down 145 61
Across 140 58.89655172
No. Grains
Chord Down Across
1 22 19
2 25 19
3 21 22

 

 

3. Data Access and Tools

Data Access

Data are available via FTP.

Volume

The total data volume is approximately 600 KB.

Software and Tools

Data are accessible using standard spreadsheet software.

Related Data Collections

4. Data Acquisition and Processing

Sensor or Instrument Description

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

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.

Data Source

Ice core samples were obtained from the National Ice Core Laboratory (NICL) in Denver, Colorado, USA.

5. References and Related Publications

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:

Table 5. Related Documents
Document Description URL
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

6. Document Information

Acronyms

The following acronyms are used in this document.

Table 6. Acronyms and Abbreviations
Acronym Description
AGDC Antarctic Glaciological Data Center
DOC Microsoft Word Document File Extension
FTP File Transfer Protocol
GB Grain Boundary
GISP2 Greenland Ice Sheet Project 2
IC Ion Chromatography
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

Document Creation Date

21 January 2010

Document URL

http://nsidc.org/data/docs/agdc/nsidc0436_baker/index.html