A comparison of sea-ice thickness measurements made using ship-mounted and airborne electromagnetic induction devices

• Other Authors: AADC (originator), AU/AADC > Australian Antarctic Data Centre, Australia (resourceProvider)
• Format: Dataset
• Language: unknown
• Published: Australian Ocean Data Network
• Subjects: oceans; ICE DEPTH/THICKNESS; EARTH SCIENCE; SEA ICE; A; ANTARCTICA; COND; COND-A; CONDUCTIVITY; DAY; FREEBOARD; ICE THICKNESS; LASER; LATITUDE; LONGITUDE; PHASE; PHASE-A; PITCH; R; RHO; ROLL; SITE; SNOW THICKNESS; SOUTHERN OCEAN; TIME; Altimeters; Aircraft; SHIPS; AMD/AU; CEOS; AMD; OCEAN > CONTINENT > GEOGRAPHIC REGION > POLAR; Antarctic; Rho; Southern Ocean; Antarc*; Antarctica; Sea ice
• Online Access: https://researchdata.ands.org.au/comparison-sea-ice-induction-devices/686317; https://data.aad.gov.au/metadata/records/ASAC_1342; http://data.aad.gov.au/aadc/portal/download_file.cfm?file_id=1202; https://secure3.aad.gov.au/proms/public/projects/report_project_public.cfm?project_no=1342; http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_1342

The PS100 laser altimeter used for these measurements was found to operate incorrectly in conditions of bright sunlight. Raw laser altimeter data contains numerous spurious values. An edited dataset is currently being created. Average sea ice floe size was encountered during the voyage was ~20-40 m. Patches of open water between floes adversely affect EM ice thickness measurements. Some sea ice was too thick to be measured by the EM instrument. An edited dataset containing acceptable sea ice thickness values is currently being created. Values provided in temporal coverage are approximate only. Metadata record for data from ASAC Project 1342 See the link below for public details on this project. --- Public Summary from Project --- This project involves field trialling of software written as part of ASAC project 1212 (2000-2001) to determine sea-ice thickness in real-time from ship-borne electromagnetic induction measurements. Computer simulation of ship- and helicopter-borne electromagnetic induction measurements over realistic sea-ice structures will also be performed in order to assess the suitability and cost-effectiveness of helicopter-mounted systems for future Antarctic sea-ice thickness measurements. Equipment used in this study were the IBEO PS100 infrared laser altimeter and the Geonics EM31 geophysical electromagnetic induction device. The fields in this dataset are: DAY is Julian day TIME is in seconds after midnight (UTC). LASER is the laser altitude above the snow/ice (metres). A zero reading indicates no return (open water). PITCH is pitch of the system in degrees. ROLL is roll of the system in degrees. COND-A is analogue conductivity from the EM31 (not used). PHASE-A is analogue in-phase response from the EM31 (not used). COND is the estimated depth to seawater (metres) from the EM31-ICE processing module. PHASE is the EM31 in-phase response (expressed as parts per thousand of the primary field). A value of 9.99 indicates the magnetic field was too large to be recorded. SITE LATITUDE LONGITUDE SNOW THICKNESS ICE THICKNESS FREEBOARD a is the electrode spacing. R is the measured resistance. Rho is the apparent conductivity (not true conductivity) = 2 aR. CONDUCTIVITY = 1/Rho.