It’s 9:45AM Thursday and the camp launched a weather balloon! It is a red balloon filled with helium that is just let go in the wind. The sky is so grey today and we need to know if the cloud ceiling is too low for the plane to land. The cloud ceiling needs to be 2,000 feet or higher so a pilot can put the plane down. They also need two miles visibility which means the pilot must be able to see for 2 miles before he can land the plane.
Today this measurement is important because many of the camp members going home have a flight out of Kangerlussuaq, Greenland tomorrow. If they don’t get home before 12 PM on Friday, they have to spend the weekend there. Air Greenland does not have any flights on the weekend from this town. Many of them have been here for several weeks and are anxious to get home.
So how do they get the ceiling height from launching a balloon? They know the weight (30 grams)and diameter (53 cm) of the helium balloon. They know the vertical speed of the ballon is 150 meters per minute. They check the time it is launched and watch the balloon until it disappears. The balloon could not be seen at 2 minutes and 40 seconds. So now they multiply the minutes by 150 meters to get the ceiling height. So the ceiling was 400 meters,or 1,312.33 feet. Wait, did the observer use binoculars? The scientist using binoculars could see the balloon longer and got a measurement that made the ceiling high enough to fly.
Other factors also determine if a plane lands here. Are there cross winds? Yesterday it was too windy so it couldn’t land. Today it is not windy at 8 knots. What is the temperature? Today it is -13C and the temperature is coming down. That means there will be less vapor in the air so some of the clouds will clear. JP the field leader, has to make this important decision. If the plane cannot land, it makes a $40,000 dent in his budget. This a very expensive flight!
Is the skiway ready? Lou has been out in the Piston Bully for 2 hours making the skiway smooth for the plane.
She clears this for every possible plane landing so she often does this for no reason! The skiway is two and a half miles long and she smooths the part of the runway that is closest to camp.She goes up and back to make her trip 20 miles long for a runway that these big planes can land on.
JP told them to come, so the plane will be here in 3 hours!
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