23 March 2009 Mapping - Part 2

After spending time with Steve Roberts, creator of GIS web tool on the Healy, I learned how to use other tools he has created. Different satellite images can be collected and pieced together to provide valuable information about the Bering Sea. Ice flow can be monitored from day to day. Many times winds push the ice in a certain directions, which can open up water in the Bering Sea. We are trying to push our way into a polynya, large open water, so that we can take water samples. Look at the photo below. The dark areas south of land show open water as the winds have pushed ice away. The open waters look like shadows on the image. The red line represents the ship's track south and west of St. Lawrence Island.

On the radar satellite image, our ship shows up as a white dot. This photo was taken on March 18, 2009. In this image, a superimposed red line represents the ship's track. Next to or under the red line you can see a white line on the image. That white line is the radar image of where the ice has been broken from the ship. If the white line doesn't match up perfectly with the red line, we know that wind has been pushing the ice.

Where are we and where have we been? Follow the ship's track in the next photo.

Steve captured satellite images of the ice flow and created a video. Watch this short video to see how the ice has moved along the southern side of St. Lawrence Island. St. Lawrence Island is outlined in yellow. The ship track is green. At the beginning of the trip a storm pushed all of the ice to the north. During the past couple of days, the winds have significantly blown the ice away and opened up the water south of St. Lawrence Island. Watch the video several times until you can focus on the ice coverage moving near the island.

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Deanna Wheeler 2009 PolarTREC Teacher