Solar Maximum Spreads the Aurora Southward
People in Anchorage and south will receive a gift from the sun in the year 2000. In what scientists call the "solar maximum," a time of increased activity on the sun, auroras should dip below the Arctic more often.
During the solar maximum, the nuclear furnace within the sun spouts more flares and develops dark splotches known as sunspots. For reasons unknown, sunspots and solar flares peak about every 11 years, and now is the time. The solar maximum will allow people as far south as Seattle to see the aurora from one to five times a year, said Charles Deehr, the auroral forecaster at the Geophysical Institute. The event probably won't affect aurora viewing in Fairbanks and points north.
The aurora will be visible from points closer to Earth's equator because the electrical circuit from sun to Earth sets up well during a solar maximum. As a solar flare explodes on the surface of the sun, it creates a shock wave in the solar wind that helps peel away the magnetic field of Earth and allow auroras to ripple closer to the equator.
Deehr said this solar maximum, which should last until about 2004, probably won't be as dramatic as ones in the past. A particularly strong solar maximum happened in the late 1950s. Deehr was in Fairbanks working at the Geophysical Institute at the time. He remembers seeing blood red arcs of aurora some nights, and red at the tops of aurora displays almost every night.
After looking at past data of the sun's cycles, Deehr speculates that the 2000 version of the solar maximum won't be as garish as the 1950s version. Though this solar maximum won't be the greatest ever known, it has the potential to turn a few satellites into space junk. According to Victor Pizzo of NOAA's Space Environment Center in Boulder, Colorado, newer computer chips within satellites could be vulnerable to increased solar activity. During the last two solar maxima, computer chips within satellites were radiation-hardened, a practice manufacturers paid less attention to after the Cold War. During the big solar maximum in the late 1950s, there were no satellites to worry about.
As an auoral forecaster at the Geophysical Institute, part of Deehr's job is to post predictions of the aurora's intensity and whereabouts on a website. He's part of a dream team of auroral and solar scientists scattered from Alaska to the East Coast who meet every day on the Internet. From their posts across America, they discuss data and run computer models to learn more about the sun-Earth connection. Each day, they put their heads together to guess where the aurora will appear the next day. To see the latest prediction, go to www.gi.alaska.edu/cgi-bin/predict.cgi.
