Cameras to monitor ice thickness
Cameras measure ice thickness for ship safety
The Cook Inlet Regional Citizens Advisory Council plans to install video cameras in and around Cook Inlet to help authorities monitor ice thickness and shifting to assist ships navigating the icy winter waters.
In the winter, Kathleen Cole’s job is like a scavenger hunt. But instead of searching for clues to uncovering hidden treasure, she searches for clues to uncovering Cook Inlet ice conditions. Cole is the National Weather Service sea ice program leader for Alaska. Ships rely on her to help them determine if they can safely pass through ice along their route, or if they need to change course.
For this important task, Cole has remarkably little data to draw upon.
She receives images of Cook Inlet from satellites, but they can be more than six hours old by the time she gets them. The quality of the images she receives is sporadic and images taken when clouds or the long winter night obscure the Inlet can’t be used at all.
Consequently, Cole is always looking for additional image sources. Sometimes, she calls upon the U.S. Coast Guard to take a picture for her while passing over the Inlet on their way to somewhere else. Or, she’ll try to see what she can of the ice through cameras aimed at the Mount Redoubt or the Homer Spit.
“We scrounge for data very well in this business,” Cole said. “That’s what I spend most of my days doing in the winter.”
This winter, however, Cole hopes to spend more time learning about Cook Inlet ice floes and less time scavenging for images. The Cook Inlet Regional Citizens Advisory Council plans to install four video cameras in and around the Inlet to help her monitor ice. The video cameras are the first of up to 10 cameras CIRCAC hopes to install in the Inlet – and will provide Cole with real-time images. This is particularly important in Cook Inlet, where extreme tides and strong winds are constantly shifting the ice. In the main body of the Inlet, the tidal range can reach 25 feet and result in currents that move nearly six miles per hour. The Inlet’s Turnagain Arm exhibits the United States’ biggest tidal range.
“Cook Inlet ice moves so much,” Cole said. “It can be up against the northern side of the Inlet in the morning and the southern side in the afternoon, either because of the tides or the winds, it moves.”
Ice forecasts are particularly important in Cook Inlet, which is a major year-round port. In evaluating Cook-Inlet ice for a given area of the Inlet, Cole tries to determine how much of the water’s surface the ice covers and how thick it is. Each ship that enters the Inlet is rated to handle a certain amount of ice, and if the ice en route is more than a ship can handle, the ship might have to change course. Even ships that can handle heavy coverage want to avoid the worst of the ice to save on fuel and engine power.
In 2007 – the year after heavy ice knocked the Seabulk Pride oil tanker from its mooring at the Kenai Pipeline Dock – Cole, with the help of CIRCAC, gained access to more ice images. CIRCAC
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Posted by Tribune Moderator
on Jul 2nd, 2009 and filed under Headline News
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