Following the Sun : Astronomy: At an egg-shaped observatory west of Sylmar, Cal State Northridge scientists study the role of sunspots and their impact on the greenhouse effect.
Many astronomers are professional night owls, going to work after sundown to gulp coffee and train their telescopes on stars, planets and other celestial bodies best viewed in the dark.
But Gary Chapman, a professor of astronomy and physics at Cal State Northridge, goes to work in the bright light of morning. In fact, he cannot even do his job at night--he follows the sun.
Chapman is director of a small observatory operated by CSUN in a remote area west of Sylmar. The main building looks like a lunar lander in an old sci-fi movie: an egg-shaped dome atop four spindly struts.
There, Chapman and a team of astronomers, students and technicians are investigating one of the least understood of solar phenomena: sunspots and their impact on the potentially devastating warming of the Earth known as the greenhouse effect.
First observed by Chinese sky-watchers thousands of years ago, sunspots are dark blemishes that are mysteriously cooler than the rest of the sun’s surface. While solar temperatures average more than 10,000 degrees Fahrenheit, sunspots are about 4,000 degrees cooler.
Scientists believe that the spots are caused by undulating coils of magnetic force--”magnetic ropes,” Chapman calls them--that twist and turn in the thermonuclear reactor of the sun’s roiling interior. When the ends of these little-understood coils hit the surface, sunspots appear, he says.
Sharp increases in the number of sunspots can have significant effects on the Earth. They produce solar flares--massive bursts of radiation and energy that are hurled into space with the force of thousands of exploding hydrogen bombs.
The flares create a sort of cosmic poltergeist effect. Electrical power fails, radio and navigation signals are disrupted, Earth-orbiting satellites obey commands never sent and the aurora borealis leaps to life.
Sunspots wax and wane in a mysterious cycle that peaks every 11 years or so. The last “solar maximum” occurred from 1989 to 1991. In March, 1989, a burst of sunspots knocked out power in Quebec, scrambled satellite communications and tripped a radiation alarm aboard a supersonic Concorde jet flying near the North Pole.
CSUN’s little observatory lies at the end of a dirt road that winds through brushy land crisscrossed by aqueducts and power lines of the Los Angeles Department of Water and Power, just north of the Los Angeles Reservoir.
Its most distinctive features are two gleaming white telescope domes known as Big Dome and Little Dome. Big Dome, which resembles a lunar lander, holds the largest telescope--a 15-foot-long tube with a 24-inch lens. According to Chapman, it is one of the two biggest solar telescopes run by a U.S. university; the other is used by Caltech at its Big Bear observatory.
While nighttime astronomers seek out mountaintops and clear skies for their work, Chapman and his cohorts delight in their observatory’s low-lying location in the often smoggy east San Fernando Valley. While it disgusts most residents, smog means better viewing for the astronomers.
That is because smog’s presence indicates an inversion layer: cooler air that slips into the Valley off the Pacific Ocean and hugs the ground. Although the inversion traps masses of stagnant, brownish air, it replaces hotter air that normally rises and can produce heat shimmers that distort the sun’s image when viewed through a telescope. Heavy smog can force a shutdown in observations, but usually it merely acts as a mild filter.
On days when winds push out the smog, “you can get a nice suntan but the viewing conditions are sometimes terrible,” said Chapman, explaining that winds make the telescope tube vibrate annoyingly.
In addition to the faculty members who use it, the $150,000-a-year observatory is used by a rotating cast of a dozen undergraduate and graduate students who, among other things, monitor day-to-day digital information gathered by Little Dome telescopes.
The Big Dome scope is used primarily by Chapman and others trying to penetrate the mysteries of the sun’s magnetic fields.
For many years, Chapman said, the conventional scientific wisdom held that because sunspots are cooler than the rest of the sun, its energy output fell when they popped up in large numbers.
Paradoxically, astronomers have since discovered that the opposite is true: Heavy sunspot activity increases the sun’s heat. Why? That is a question Chapman and other astronomers are studying intensively.
Although temperature changes on the sun increase or decrease the amount of heat the Earth receives only by a fraction of a percent, such fluctuations, over a long period, could have major implications for this planet’s climate, Chapman said.
He and other astronomers believe that a sudden and unexplained disappearance of sunspots may have been responsible, at least in part, for a period of unusually harsh winters in Europe, known as the Little Ice Age, stretching from about 1500 to 1850.
People starved when wheat crops failed in Poland. Glaciers ground into Swiss valleys faster than anyone could remember.
“There are several paintings of Rembrandt, for example, that show ice skaters on the canals in Holland. It never gets that cold in Holland anymore,” said Stephen Walton, another CSUN professor who performs sophisticated computer analyses of solar data at the observatory’s equipment-jammed headquarters shack.
At the moment, Chapman is trying to find out if there are correlations between changes in the sun’s magnetic fields and variations in its heat output.
Understanding the sun’s output is important because it may help scientists better understand the greenhouse effect, which some contend--in a theory that is still argued over--is slowly warming the Earth. The theory holds that increasing amounts of heat generated by sunlight are being trapped in the atmosphere, partly because of changes to the atmosphere caused by gases produced by humankind.
If scientists can measure the sun’s output more precisely, they can subtract increased solar energy from the amount of warming caused by humanity. The result could lead to better strategies for reducing any human activities that contribute to global warming.
“If the sun’s increased output warms the Earth, and if man’s effects are warming the Earth, we need to disentangle those two,” Chapman said.
He and others from CSUN are not the only people drawn to the observatory. Its futuristic looks also have attracted movie and television producers who used it as a backdrop.
The observatory appeared in the opening scenes of Woody Allen’s “Sleeper,” as well as installments of the CBS science series “In Search of . . .,” hosted by Leonard Nimoy.
It also turned up in a movie called “Galaxina,” a forgettable sci-fi tale about a group of futuristic bikers who terrorize an ex-Playboy centerfold lashed to one of Big Dome’s struts.
“I don’t even want to talk about that one,” Chapman said.
