Get Data

DOWNLOADING DATA VIA FTP

Data can be downloaded through a Web browser or command line via FTP. When using a Web browser, the FTP link first directs you to an Optional Registration Form that if filled out, will allow you to receive notifications about updates or processing changes related to that specific data set. After completing the Optional Registration Form, the FTP directory becomes available. For additional help downloading data through an FTP client, go to the How to access data using an FTP client support page.

FTP

Data Set ID:
NSIDC-0100

Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica, Version 1

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. Thus a better understanding of the physical properties of snow will improve interpretation of ice core records of atmospheric composition.

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

Geographic Coverage

Parameter(s):
  • Snow/Ice > Snow/Ice Temperature
Spatial Coverage:
  • N: -81, S: -81, E: -148, W: -148

Spatial Resolution: Not Specified
Temporal Coverage:
  • 25 November 1998 to 29 June 1999
Temporal Resolution: Not specified
Data Format(s):
  • Microsoft Excel
  • ASCII Text
Platform(s) GROUND STATIONS, GROUND-BASED OBSERVATIONS
Sensor(s): CORING DEVICES, PERMEAMETERS, THERMOMETERS
Version: V1
Data Contributor(s): Mary Albert

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.

Albert, M. R. 2001. Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica, Version 1. [Indicate subset used]. Boulder, Colorado USA. NSIDC: National Snow and Ice Data Center. doi: http://dx.doi.org/10.7265/N5S46PVZ. [Date Accessed].

Back to Top

Collapse All / Open All

Detailed Data Description

Format

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

Background color on
File Size

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

Background color on
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
Background color on
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

Background color on
Temporal Coverage

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

Background color on
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).

Background color on

Software and Tools

Background color on

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.

Background color on

References and Related Publications

Contacts and Acknowledgments

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

Acknowledgments: 

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

Document Information

DOCUMENT CREATION DATE

20 November 2001

No technical references available for this data set.
No FAQs or How Tos available for this data set.

Access complete Knowledge Base

Questions? Please contact:
NSIDC User Services
Phone: 1 303 492-6199
Email: nsidc@nsidc.org