Satellite images mosaics and animations

The Canadian Ice Service produces the following types of images:

• Synthetic Aperture Radar (SAR) Mosaics
• MODIS Composites
• Ice in Canadian Waters
• Ice in Canadian Waters Animation

Synthetic Aperture Radar (SAR) Mosaics

These mosaics of RADARSAT Constellation Mission (RCM) and Sentinel-1 satellite images complement the weekly regional sea ice charts produced for five regions in Canada's navigable waters. The mosaics provide an overview of ice conditions for a wide area, while maintaining as much detail as practical for low-bandwidth access. However, the image tone is affected by the incidence angle, rough sea conditions, the presence of water on the surface of the ice during the melting season, and by heavy rainfall. The tone balancing algorithm used to generate seamless mosaics aims to adjust the image tone at the boundaries between the individual images, which dampens these effects to facilitate interpretation, but may also introduce new artefacts where the tone of bordering images is very different. Therefore, they should be interpreted along with the corresponding regional ice charts.

The mosaics will be released on a weekly basis, normally on Wednesday afternoon, generated from data acquired over the previous weekend from Saturday to Tuesday that are used to produce the weekly Regional charts. The mosaics put the most recent images in the foreground, using RCM imagery first and filling the remaining gaps with Sentinel-1 imagery, again, from newest to oldest. Mosaics are generated and displayed as multiple polarization RGB false-colour composites, as indicated on the graphic. The date range for the imagery is indicated in the information box at the bottom of the graphic. Four vector layers are overlaid indicating the shoreline (yellow), the median ice edge from the CIS 30-year (1991-2020) ice climate normals (green), the demarcation of the area of < 1/10 ice (blue), i.e. open water, and the landfast ice edge (pink). The brightness of areas outside the 1/10 ice edge is intentionally lowered to reduce effects from wind-roughened water. The information for the open water and landfast ice edge data are taken from the corresponding regional ice charts.

MODIS Composites

The product consists of 7 day MODIS satellite composite images compiled to create a mosaic image of the Arctic Basin.  It is available when there is sufficient daylight to show the ice conditions.

The product is presented in two ways:  a True-Colour Composite image and a False-Colour Composite image. 

• The True-Colour Composite image: features appear in their natural colour (i.e. snow, sea ice and clouds all appear white).  As a result, care must be taken to distinguish sea ice from clouds.
• The False-Colour Composite image: image highlights colour differences between sea ice and cloud.  As a result, sea ice and snow appear light blue and clouds appear white (and purple over water).

The MODIS composite is created every Wednesday using the preceding week’s images. 

Ice in Canadian Waters

This product is generated once per day and consists of the last 20 days of Canadian Ice Service's Daily and Regional Charts which are then compiled to create a graphical product that is intended to give the user a general portrayal of ice in Canadian waters.

The product is created by superimposing the input data on top of one another, with the most recent data appearing on the top. The output is then symbolized to indicate the varying concentrations of ice.

Lower concentrations of ice are depicted in blues; higher concentrations are depicted in greys and white; areas of no ice are shown in dark blue; and areas not analyzed by the Canadian Ice Service within the given time period are depicted in black.

Ice in Canadian Waters Animation

This product is generated once per day and consists of the last 10 days of Canadian Ice Service Ice in Canadian Waters products. The animation is intended to give the user a general portrayal of how ice in Canadian waters has changed over the indicated period.

The product is created by inserting the input Ice in Canadian Waters products into frames in the animation.

Lower concentrations of ice are depicted in blues; higher concentrations are depicted in greys and white; areas of no ice are shown in dark blue; and areas not analyzed by the Canadian Ice Service within the given time period are depicted in black.