Annual Arctic Ice Atlas
The 2006 Arctic Ice Atlas complements a similar collection prepared each year since 1990. These and earlier programs document Arctic winter ice conditions with SAR (Synthetic Aperture Radar) imagery back to 1986/ 87. The main objective in compiling this document is to maintain a climatological archive of winter ice conditions, providing a clearer understanding of variations in Arctic ice regimes both geographically and seasonally.
This year information from a satellite borne SAR system has been used almost exclusively. SAR data from the RADARSAT satellite was captured by the Prince Albert (Saskatchewan), Gatineau (Québec) and Fairbanks (Alaska) receiving stations. The data were captured between January 28th and February 1st, 2006.
In this album the Arctic is divided into four main regions as well as three larger scale sub regions. The Eastern Arctic, Western Arctic and Hudson Bay regions include an analysis of the data. The ice analyses have been performed by Canadian Ice Service (CIS) personnel. Supporting information included meteorological summaries, ice thickness reports and NOAA AVHRR imagery. An explanation of the nomenclature on the analysis charts can be found on the Key to Ice Symbols page. A more detailed explanation of the terminology is available in MANICE (Manual of Standard Procedures for Observing and Reporting Ice Conditions) prepared by the Meteorological Service of Canada, Environment Canada.
For most regions, the mosaic represents a composite of orbits from several days. The period over which the data was acquired is noted on each page. Basic geographic annotation is provided on the mosaics as a reference. During the image production, the raw data was radiometrically adjusted and enhanced. The overlapping orbits were then digitally seamed together to give a balanced and finished picture. The SAR data was displayed and analyzed at approximately 100 m resolution. Although the data was captured at 50 m pixel spacing, all of the image mosaics have been resampled to 200-400 m pixel size.
ENVISAT IMAGERY - This is the second year we are incorporating ASAR data from the European Space Agency’s ENVISAT satellite. This data was used to create the pictures for each zoom-in area. The ENVISAT imagery was received at 75 m resolution, but was re-sampled to 150 m for the final mosaics. The images were captured during the time period of January 31st to February 17th 2006. Each image contains two co-polarization layers; layer 1 being horizontal transmit – horizontal receive: HH, and layer 2 being horizontal transmit – vertical receive: HV. Dual polarization allows for multiple backscattering of radiation to occur over the sea ice, which provides greater detail for each image. An RGB composite image containing both layers results in 3 possible band layers for each color. This allows for enhancement of sea ice characteristics.
All the RADARSAT data contained in this atlas is the property of the Canadian Space Agency (CSA) and subject to copyright ©CSA 2006. Most of the RADARSAT data was acquired by the Canadian Centre for Remote Sensing (CCRS) and processed by MDA - Geospatial Services. Imagery for the Chukchi Sea and Western Arctic areas was captured by the Alaskan Satellite Facility. This atlas has been published with the permission of both MDA and CSA.
The successful completion of this project was made possible with the able assistance of many people. The following contributions should be noted:
- Project Manager....................................... Dan Fequet, Canadian Ice Service (CIS)
- RADARSAT SAR data acquisition........... CSA, MDA, Matt Arkett (CIS)
- Mosaic production.................................... Campbell Inwood, (CIS-COOP)
- Image analysis........................................... Jacques Collin, (CIS)
- Climate summary....................................... Rick Power, (CIS)
Funding for this project was provided by the Canadian Coast Guard of Fisheries and Oceans Canada, and the Canadian Ice Service of Environment Canada.
