Annual Arctic Ice Atlas - Winter 2015-2016
[Also available in PDF; 6.87 MB]
The 2015-2016 Annual Arctic Ice Atlas is part of a continuing series, prepared each year by the Canadian Ice Service since 1990. This collection of atlases documents Canadian Arctic winter sea ice conditions to provide a comparison from year to year. In this year’s atlas, graphical depictions of the winter ice conditions primarily based on Synthetic Aperture Radar (SAR) data are presented.
The SAR data used in the compilation of the image mosaics in this year’s atlas came from the RADARSAT-2 satellite. The data was captured by the Prince Albert (Saskatchewan) and Gatineau (Quebec) receiving stations, between January 29th and February 1st, 2016.
In this edition of the atlas, the Arctic is divided up into five main regions and three larger-scale snapshot regions. All of the regions have a SAR image mosaic, but three of the main regions (the Eastern Arctic, the Western Arctic, and Hudson Bay) also include an analysis of the data. The ice analyses were created by Environment and Climate Change Canada's (ECCC) Canadian Ice Service (CIS) personnel, who used additional supporting information (including meteorological summaries, ice thickness reports and NOAA AVHRR imagery) in their preparation. An explanation of the nomenclature on the analysis charts can be found on the Sea Ice Symbols page. A more detailed explanation of the terminologies used is available in the Revised Ninth Edition of MANICE (Manual of Standard Procedures for Observing and Reporting Ice Conditions), prepared by the Canadian Ice Service of Environment and Climate Change Canada.
The production of this year’s atlas involves an automated algorithm developed by CIS staff which was utilized to: apply radiometric enhancements to the input images; stitch the overlapping images into a seamless mosaic; and then colour-balance the final output. The mosaicked images now display “dual-polarization” imagery consisting of horizontal transmit / horizontal receive (“HH”) as well as horizontal transmit / vertical receive (“HV”). Generally speaking, and for discussion purposes here, varying polarizations in SAR data are akin to the spectral bands in an optical image (e.g. LANDSAT).
In order to display the dual-polarized imagery, the mosaicked imagery is presented in colour. The output consists primarily of yellow and purple hues by assigning the following polarization combinations to the RGB colour spectrum: Red = HH, Green = HH, and Blue = HV. During the winter months the horizontal transmit / vertical receive (HV) tends to highlight areas of second-year / multi-year ice as well as areas of roughness which appear as areas of blue to purple in the mosaic.
For most regions, the SAR image mosaic is a composite of satellite images captured over several days. In some instances older or newer data was used to substitute for small areas of missing data. The period over which the data was acquired is noted on each page. For all areas, the SAR data were captured at a resolution of 50 metres / pixel, the data were analyzed at approximately 100 metres / pixel and the published image mosaics were resampled to approximately 500 metres / pixel.
All the RADARSAT-2 images contained in this atlas were processed by and are the property of the MacDonald, Dettwiler, and Associates Ltd. (MDA), and are copyright © MDA 2016 - All Rights Reserved. RADARSAT is an official mark of the Canadian Space Agency. All data acquired for this atlas has been archived by the Canada Centre for Mapping and Earth Observation (CCMEO). This atlas has been published with the permission of MDA.
The successful completion of this project was made possible with the able assistance of many people. The following contributions should be noted:
- Project Manager: Steve McCourt (ECCC)
- RADARSAT SAR data acquisition: MDA, Céline Fabi and Ryan Griffin (ECCC)
- Mosaic production: Correy Schaad (ECCC)
- Mosaic algorithm: Yi Luo (ECCC)
- Image analysis: Benoit Montpetit / Stéphanie Tremblay-Therrien, Bradley Drummond, Jason Ross (ECCC)
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