1. Australian Antarctic Data Centre
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4. AAD_Ant_WLD_firn_temp

Description

Measurements of temperature within the snow / firn cover in Wilkes Land East Antarctica were made along the routes of oversnow traverses operating out of Casey (66.6 S 110 E). In general, measurements were made at a nominal depth of ten metres as a first estimate of mean annual surface temperature of the ice sheet, and for many sites, at some additional depths, typically around twenty metres. Actual depths of measurements are included with the temperature data as well as date of observation. No attempt has been made to apply any correction for seasonal or interannual variation.

Two different methods were used to drill the access holes: an ice coring auger (usually PICO drill, originally SIPRE drill); a steam drill. In some areas depth of drilling was limited by problems associated with the texture of the firn and difficulties in recovery of material from the hole.

Where relevant, date of drilling is included with the data, or time elapsed between drilling and temperature measurement. Temperature measurements were made using 100 ohm platinum resistance elements with resistance measured using a 'Leeds and Northrup' resistance bridge. The bridge uses a zero/nul measurement technique, thus avoiding heating effects in the sensor Refer quality entry for further details).

These data form part of the data collected for ASAC projects 456 (Properties and Structure of Antarctic Snow and Ice ), 458 (Characteristics, Dynamics and Mass Budget of the Ice Sheet in Wilkes Land ) and 2224 (Glacier dynamics and mass discharge from the Antarctic ice sheet, 45 degrees -160 degrees E) - ASAC_456, ASAC_458, ASAC_2224).

The fields in this dataset are:

Marker
Date
Temperature (degrees C)
Depth of Observation (m)
Latitude
Longitude
Drill
Time since drilling
Comments

Quality

Location information of each measurement site included with the data are based on nominal coordinate values. These will be refined when associated survey data compilation is completed.

Temperature measurements are accurate to better than 0.1 degree C unless otherwise noted. All temperatures were measured using 100 ohm (nom) platinum resistance temperature elements calibrated using an ice point and resistance measured using a 'Leeds and Northrup' Temperature Bridge which uses a null point method to avoid heating effects in the sensor.

Sensors were also checked against a 'standard' probe which had a 'NATA' calibration.

For most sites, multiple measurements were recorded over many hours in order to assess the rate of equilibration of the sensor with the temperature of the firn. The sensor was usually mounted in a device that allowed it to be brought into positive contact with the hole wall, or with the base of the hole.

Access

These data are publicly available for download from the provided URL.

Temporal Coverages

• Start date: 1978-01-01 - Stop date: 1986-12-31

Spatial Coverages

Science Keywords

• EARTH SCIENCE > CRYOSPHERE > SNOW/ICE > SNOW/ICE TEMPERATURE

Use Constraints

This data set conforms to the CCBY Attribution License
(http://creativecommons.org/licenses/by/4.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=AAD_Ant_WLD_firn_temp when using these data.