Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica (M. Albert)

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Data Set Summary

This data set includes measurements of snow and firn temperature and permeability collected between November 1998 and June 1999 at Siple Dome. The physical characteristics of snow determine the nature of air-snow exchange processes, which in turn affect chemical records in ice cores. Therefore, we need to understand snow's physical properties in order to better interpret ice core records of atmospheric composition.

Data are available via ftp in both ASCII and Excel formats.

Citing These Data:

Please cite these data as follows:

Albert, M.R. 2001. Snow and firn temperature and permeability measurements from Siple Dome, Antarctica. Boulder, CO: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N5S46PVZ.

For permeability data, also cite:

Albert, M.R., E.F. Shultz, and F.E. Perron. 2000. Snow and firn permeability at Siple Dome, Antarctica. Annals of Glaciology 31: 353-356.

Overview Table

Category Description
parameter(s) snow permeability, snow temperature
spatial coverage data collected at Siple Dome, Antarctica
temporal coverage Nov 1998 to Jun 1999
data format tab-delimited ASCII files and Excel files
file size individual files are 2, 9, 1400, and 2400 KB
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:

Investigator Name and Affiliation:

Mary Albert
U.S. Army Cold Regions Research and Engineering Lab
Hanover, NH     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

Acknowledgments:

This research was supported by NSF OPP award #9526601, Near-Surface Processes Affecting Gas Exchange: West Antarctic Ice Sheet.

2. Detailed Data Description:

Format:

Data are available as tab-delimited ASCII files and as Excel spreadsheets.

File Size:

Temperature data files are ~1400 (ASCII) and ~2400 (Excel) KB; permeability data files are 2 (ASCII) and 19 (Excel) KB each.

Sample Data Record:

Permeability data files comprise two columns containing depths and permeability data, respectively:

        Depth (cm)	Permeability x10^-10 m2
        -5	        6.3
        -20	        10.3
        -33.5	        76.4
        -50.5	        22.8
        -64	        73.5
        

Temperature data files contain 32 columns presenting temperatures as functions of time and depth. The first 13 columns are represented below:

                				Height above bottom thermocouple							
        Date and Time	   ID  year  day  time	0 cm	10	20	210	413	473	493	508
        11/25/1998 17:00  111  1998  329  1700	-26.58	-27.04	-26.75	-28.13	-26.66	-24.5	-22.99	-21.4
        11/25/1998 18:00  111  1998  329  1800	-26.55	-27.01	-26.71	-28.09	-26.61	-24.45	-22.96	-21.33
        11/25/1998 19:00  111  1998  329  1900	-26.56	-27.02	-26.73	-28.09	-26.61	-24.45	-22.97	-21.32
        11/25/1998 20:00  111  1998  329  2000	-26.56	-27.03	-26.73	-28.1	-26.61	-24.45	-22.98	-21.31
        11/25/1998 21:00  111  1998  329  2100	-26.52	-26.98	-26.68	-28.05	-26.57	-24.41	-22.95	-21.26
        11/25/1998 22:00  111  1998  329  2200	-26.56	-27.03	-26.74	-28.1	-26.62	-24.46	-23  	-21.29
        11/25/1998 23:00  111  1998  329  2300	-26.58	-27.05	-26.76	-28.12	-26.63	-24.47	-23.01	-21.28
        11/26/1998 0:00   111  1998  329  2400	-26.6	-27.07	-26.78	-28.14	-26.66	-24.49	-23.01	-21.29
        11/26/1998 1:00   111  1998  330   100	-26.6	-27.07	-26.78	-28.14	-26.65	-24.48	-23.01	-21.27
        
 

Spatial Coverage:

Data were collected at Siple Dome (81 degrees south latitude, 148 degrees west longitude) on the West Antarctic Ice Sheet. Permeability measurements describe a 2 m snow pit and a firn/ice core extending to a depth of almost 15 m; temperature measurements extend to 6.5 m depth.

Study Area Location Map:

The map below indicates the location of Siple Dome (SD) in western Antarctica.

Map: Location of Siple Dome study site

 

Temporal Coverage:

Data were collected between 25 November 1998 and 29 June 1999.

 

Parameter or Variable:

Temperature measurements are in degrees Celsius, and permeability is expressed in m2. Temperature is given versus depth (in cm) and time; permeability is given versus depth (in cm).

Note that permeability is not expressed in Darcy units. Darcy units are a function of fluid properties as well as medium properties, and the investigator in this case chose to express permeability as a function only of the medium and not of the fluid. This is sometimes referred to as "intrinsic permeability." The volumetric flux of the fluid is related to the pressure drop through the permeability and the fluid viscosity as: veloc = - (permeability/viscosity)*(dP/dx).

 

3. Data Access:

Data are available via ftp.

Related Data Collections:

4. Data Acquisition and Processing:

The investigator measured temperatures at the site using type "T" 24-gauge thermocouples (with special limits of error) and a Campbell CR10 datalogger. Ice bath calibrations of thermocouple/datalogger system before installation indicate accuracy within 0.1 degree C.

Permeability samples were removed with a cylindrical cutter and analyzed with a custom-made calibrated air permeameter with double-cylinder head to pump air through the sample while measuring the air-flow rate and pressure drop across the sample (Albert et al. 2000.). Pit measurements were made in the field. Firn core permeability measurements were performed on core samples in the lab.

5. References and Related Publications:

For more information about permeability measurements, please consult:

Albert, M.R., E.F. Shultz, and F.E. Perron. 2000. Snow and firn permeability at Siple Dome, Antarctica. Annals of Glaciology 31: 353-356.

6. Document Information:

Document Creation Date:

20 November 2001

Document Revision Date:

13 December 2001

Document Curator:

NSIDC writers, nsidc@nsidc.org

Document URL:

http://nsidc.org/data/docs/agdc/nsidc0100_albert/index.html