|Here Comes the Sun|
Space Weather Forecasting
Fighter pilots begin each day by checking the weather. Maybe you check the weather to decide what to wear. Fighter pilots check the weather because their lives depend upon it. You might check the temperature and precipitation. Pilots check for air pressure changes, storm fronts, precipitation, wind speeds, cloud density and altitude, and jet streams.
Scientists at NASA also check the weather because the astronauts lives depend upon it. They check "space weather" forecasts. The National Oceanic Atmospheric Administrations Space Environment Center (NOAA/SEC) in Boulder, Colorado, provides NASA with solar forecasts every day at 10 AM. The SEC counts and monitors sunspots, coronal flares, solar wind speeds, and the production of X-rays, gamma rays, radio waves, and microwaves.
Solar Weather Watch Bulletin: Jan 17-24, 2001. Along with higher-than-normal solar weather activity, the sun has unleashed a series of significant solar flares. A spike of X-ray energy originated late January 17th from a sunspot group located in active region 1287. First observed last week, the group appears to be shifting. However, it could unleash additional turbulence before it rotates behind the sun next week. "The active regions sunspots are growing in complexity. Additional satellite-endangering solar activity could erupt within the next month," observes NOAA/SEC senior forecaster Mark Billtagh.
The sunspot described in this weather report was eleven times the size of the earth. The storm erupting from this active region was one of the strongest in recorded history.
Approximately every 11 years, the sun goes through a cycle in which the number of sunspots, flares, and solar storms produced by the sun rises and falls. Data recently gathered from the SOHO satellite suggests that the North and South poles of the sun actually flip-flop, changing places and creating huge amounts of solar activity. When this activity peaks, the sun is at its solar maximum.
Weather on Earth
Extreme coronal mass ejections, called solar proton events, have been known to induce electrical currents above the earth. On several occasions this electrical phenomena has interfered with electric power transmission equipment in northern Canada. Such events have also caused the failure of dozens of navigation and communications satellites over the years.
Earth's Natural Protection
Solar protons and other radioactive particles also
interact with the earths magnetosphere. The earth's magnetic field
lines act like electric wires. As the charged particles from the sun cross
the magnetic field lines, the particles spiral around and travel down
the lines toward the earths North and South Poles. Upon entering
the ionosphere, some of the particles collide with gas molecules. This
creates the spectacular light displays known as the aurora borealis
(northern lights) and the aurora australis (southern lights).
The interaction of the solar particles and earth's magnetic field tends to act like an electric power generator and can produce what some scientists estimate to be almost 100,000 volts of electricity. This "power-generator" creates its own magnetic field, which, along with the Earths magnetic field, forms an electric "power grid" that distributes electricity throughout the Earth's upper atmosphere. On the surface of the earth, we are safe from this high-powered, electric grid. Our communications satellites, however, and our earth-bound power plants can be affected by these high-altitude power surges.
Although humans are not directly affected by solar flares, some animals may also experience temporary physical malfunctions. Pigeons, dolphins, whales, and other migratory animals have internal biological compasses composed of magnetite that is wrapped in bundles of nerve cells in their heads. The electrical and magnetic fields produced during geomagnetic storms interfere with the animals compasses and disable their navigational systems. At times, NOAA/SEC may provide space weather forecasts to homing pigeon farmers who are worried about their pigeons ability to return home.
How We Know