 by Ned Rozell December 04, 2004
I have three of them attached to my home, and I've memorized three phone numbers of recorded voices that tell me the temperature at three other places. I know I have a problem, but the busy signals I hear during a cold snap tell me I'm not alone. Since I don't seem to be the only one afflicted with mercury madness, I'll indulge in temperature trivia lifted from my favorite non-human sources: the textbook Meteorology Today and It's Raining Frogs and Fishes by Jerry Dennis. First, a look at what our thermometers are measuring. Because hot and cold are relative terms, sometimes our senses can't be trusted to tell us the difference. For example, a tub of ice water will feel warm if you stick your foot in it after walking barefoot at 40 below. Real hot and cold can be thought of as a measurement of motion: the temperature of water, air, motor oil or any other substance is a measure of the average speed of molecules and atoms within the substance. The faster the molecules are bumping around, the higher the temperature. If we had a freezer capable of cooling air to minus 459 degrees Fahrenheit, for example, the oxygen, nitrogen and hydrogen molecules within air would theoretically stop moving. This point, known as absolute zero, is the starting point of the Kelvin scale, which was named after Lord Kelvin, a British scientist who lived from 1824 to 1907. The Kelvin scale is useful for temperature measurements in space. The average temperature of the universe is about 2.7 Kelvins, or minus 454.8 degrees Fahrenheit. Temperatures on Earth are fortunately much higher because of several factors: the sun's warmth, the ability of Earth's surface to absorb solar radiation, and the insulating effects of the atmosphere, a 30-mile thick shell of gases. Because Earth is tilted on its axis, the north and south poles lean away from direct sunlight for much of the year. Although we northerners tend to talk tough about our cold snaps, those on the other end of the globe have much more chilly reasons to brag. The coldest temperature ever measured was minus 129 degrees Fahrenheit, at Vostok, a Russian scientific station in Antarctica, on July 21, 1983. Antarctica, a mountainous continent larger than the United States (even with Alaska tacked on), is colder than the North Pole. Each year, Antarctica averages at least 35 degrees colder than the Arctic. The highest temperature ever recorded at the geographic South Pole, located on Antarctica, is 5.5 degrees. The average yearly temperature at the same spot is minus 57 degrees. The lowest temperature recorded this side of the equator, minus 90 degrees, was recorded at Verkhoyansk, Russia. Closer to home, Snag, a lonely outpost in the Yukon Territory, holds the North American cold record with a reading of minus 81 on February 3, 1947. That just nips Alaska's coldest official temperature, a minus 80 felt on January 23, 1971 at Prospect Creek off the Dalton Highway north of the Yukon River. Now that you're all chilled with thoughts of Alaska's air molecules at their most sluggish, a warmer thought: the official high temperature record for Hawaii is identical to Alaska's warmest temperature. Thermometers in Fort Yukon (in 1915), and Pahala, Hawaii (in 1931), reached the same high temperature, a level that hasn't been reached since--100 degrees.
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 (nrozell@gi.alaska.edu) is a science writer at the institute.
|