The year 2000, it is believed, will be the solar maximum for the current solar cycle. While sunspots have been used historically to indicate levels of solar activity, other solar features increase in number and intensity along with the fluctuations in the sun's magnetic field structure. This NASA illustration shows the earth's magnetosphere and its interaction with the sun. Effects on Earth Ordinarily, the earth's own magnetic field protects it from most of the sun's emissions. But during periods of intense solar activity geomagnetic storms can produce heightened, spectacular displays of the Aurora Borealis and Aurora Australis, known as the Northern and Southern Lights.
Geomagnetic storms can also disrupt radio transmissions and affect power grids.
Energetic electromagnetic bombardments can interfere with the transmission of radio waves and the flow of electric current in wires. Radio operators are familiar with solar maximum and have to deal with an increase in static on the airwaves. Occasionally, radio signals can be completely drowned out. Power grids can be overloaded by these same bombardments. In 1989, during the last solar maximum, the power grid that supplies Canada's Quebec province was knocked out by a geomagnetic storm.