|
|
|
| Current Issue |
|
|
| Resources |
|
|
|
Forecasting Solar Activity
| Article
# : |
16039 |
|
|
Section : |
NATURAL SCIENCE
|
| Issue
Date : |
7 / 1989 |
3,241 Words |
| Author
: |
Joann Temple Dennett
Joann Temple Dennett is a research associate of the office of
the associate vice president for research at the University
of Colorado. |
The sun is essential to human existence. Without the Sun, the Earth's oceans would freeze, neither wind nor clouds would form, and all life would disappear from the planet. The Sun supports life, but it also poses a threat to the ways of modern technological living. Solar flares--giant eruptions of charged particles and radiation from the surface of the Sun--and the magnetic storms they can generate on Earth create a variety of problems: interrupting electrical power distribution, blacking out radio communications, and increasing the corrosion rate of oil and natural gas pipelines. Astronauts in space and passengers in high-altitude jets can be exposed to dangerous solar radiation. And some scientists argue that solar phenomena affect not only our weather but animals and humans as well.
Sunspots and solar flares are companion phenomena. Reporting such spots on the necessarily "perfect" creation of God assured Galileo a visit from the Inquisition; yet, ancient Chinese astronomers had been making records of the dark speckles that came and went on the surface of the Sun since long before the birth of Christ. Aided by the invention of the telescope, Galileo first reported details about these mysterious spots--spots that seemed to occur in cyclical waves.
Scientists now know that sunspots do occur in cycles. An 11-year cycle of sunspot activity seems to emerge from the detailed records of the 21 sunspot cycles observed since 1755. The Sun is now experiencing what some scientists think may be the most active cycle ever, a time of violent solar storms that promises to be a record-setter in many ways.
For example, on March 6 the largest, most active sunspot ever seen had solar scientists around the world poised to warn of impending flare effects on Earth. They were not disappointed--this unusual spot created a new, giant flare almost daily, saturating the space between the Sun and Earth with solar X-rays, gamma rays, and protons, and creating surging waves in the solar wind that disturbed the Earth's magnetic field with unprecedented regularity.
One effect of this disturbance was a spectacular display of auroras visible as far south as Brownsville, Texas, and as far north as Exmouth, Australia, only two degrees from the Tropic of Capricorn. This auroral light show was caused by solar particles spiraling into the Earth's atmosphere along the magnetic trackways that lead to the polar regions.
When the sunspot, more than 90 times the size
...
Read Full Article
Look for this article in Ask.com
|
|
