Story last updated at 6/24/2009 - 10:46 am
"Did you feel it?" a friend asked on June 20th, at about 9:45 p.m. on a sunny Alaska night.
No, it wasn't another earthquake. At that moment, the sun paused on its journey around our northern horizon, and we, for a second or two, experienced summer solstice.
Solstice is the precise time when the top of the world nods deepest toward the sun. Here's what it's like when solstice (a word derived from Latin words meaning "sun standing still") arrives in Alaska:
Darkness, our old friend, has vanished. Even in Southeast, a person can read a book outside at midnight without a headlamp. Forget the aurora; it's still there, dancing in the upper atmosphere, but we can't see it. Stars, too, are a memory.
Male songbirds fill the forests with melody. Mother birds warm millions of little eggs, in nests from Attu to Annette. Alaska is bursting with migrants, here to exploit one of the richest populations of insects on the planet. Ravens, chickadees, and other winter comrades share the boom.
Alaska creatures that depend on darkness - little brown bats, flying squirrels, and owls - somehow make a go of it when rays of sunlight illuminate their roosts at 11 p.m. Perhaps more appreciative of the constant light are the millions of salmon shooting upstream like fading torpedoes. When they stop, they will mate and die, their bodies enriching water, soil, bird and mammal.
All that solar radiation striking the tundra, the trees, the pavement and the people has a profound effect. Plants grow with such speed that gardeners wish they had photographed the tomato stems each day, because they swear they are six inches taller. Those gardeners savor the sun on their skin, which converts sunlight to vitamin D, which will show up in their bloodstreams in one month.
Glaciers flood their gravel arteries with meltwater, surging in the afternoon and relaxing at night and early morning. They are shedding last winter's snowfall, and some are now losing blue ice that fell as snow hundreds of years ago, during a cold period called the Little Ice Age.
The solstice warmth is penetrating the ground, thawing the soil that froze last fall and winter. As the summer progresses, the heat will slowly penetrate to its maximum depth, sometimes thawing permafrost - ground that had remained frozen through the heat of at least two summers - another relic of a very cold time gone by.
The sea ice floating like a jigsaw puzzle on the Arctic Ocean is now on the wane. Non-stop sunlight melts it and warms the water around it, causing more ice to melt. But if you want to sneak through the Northwest Passage in your dinghy, solstice is not the time to try. The icepack won't shrink to its minimum until mid-September.
Now is a time you might smell molecules of singed aspen and black spruce, a nostalgic scent that tells you a forest fire is consuming part of Alaska. Each year, about 10 times more land in Alaska burns than in any other state; in 2004, an area the size of Vermont burned, and, with its brownish haze, Alaska looked a bit like Beijing.
Alaskans hope to avoid a repeat of that year, but all our solstice sunshine encourages the development of cumulonimbus clouds, which give birth to lightning strikes. On a day with fertile conditions, the flammable surface of Alaska can receive more than 7,000 hits from lightning. Some of those do nothing but char tundra; some strike tinder-dry trees that burst into flames and inspire the growth of a mushroom cloud.
As many of you are reading this, summer solstice has passed. The northland has begun its tilt toward the other solstice, six months from now, a time when the Alaska sun peeks rather than soars over the horizon, providing less sensation on your skin than the tickle of an ant in midsummer.
This column is provided as a public service by the Geophysical Institute, University of Alaska Fairbanks, in cooperation with the UAF research community. Ned Rozell is a science writer at the institute.