Green Up
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The days are long in June, and in parts of Alaska the sun won't set. In the arctic, the midnight sun means the tundra gets a sudden make-over. Weather notebook correspondent Amy Mayer explains.

Alaska Department of Fish & Game

Amy: "You might think of spring as a season that begins with a few buds on the trees, continues with hardy early flowers and stretches from March into May. Not so in northern Alaska, where summer's too short to slip into casually. Instead of spring, in the arctic, locals and scientists talk about 'green-up'. University of Alaska Fairbanks biology professor Skip Walker's been on the coastal plain during green-up."

Skip: "Well, it is a relatively quick process that usually occurs during the first part of June and it's the greening of the leaves on the willows and the birch and the sedges that totally transforms the arctic tundra from a very brown landscape to by the middle of July a very green landscape."

Amy: "Walker says the plants don't have much time for their whole life-cycle. The snow doesn't melt until the end of May, and then the ground freezes-up again around the first week in August. Fortunately, during the short summer, the days are long. Retired UAF biologist Dave Klein says the midnight sun nurtures arctic vegetation."

Skip: "Plants grow very rapidly under this 24 hours of sunlight and consequently during this rapid growth they're of highest quality."

And that's good news for critters. Tomorrow we'll talk about how these power-packed plants help migrating caribou.