Sunspots, Solar Flares and Space Weather - Can They Affect Earth?

Sunspots and other solar phenomena have been well documented for hundreds of years. They are responsible for the Aurora Borealis, Aurora Australis and other atmospheric phenomena on our planet, but, other than producing fantastic light shows, can they affect Earth?

Sunspots

Sunspots are cool, darker places on the sun's surface surrounded by brighter material. At 6,700 degrees Fahrenheit, they are only cooler by solar standards. Sunspots follow an irregular 11-year cycle, increasing and decreasing in frequency with this cycle. They are caused by the sun's magnetic field welling up into the photosphere. There has been a noted connection between sunspot activity and earth's climate, though exactly what that connection may be, and what the cause might be are still being debated. It is known that during the late 17^th century the sun went through a period of sunspot inactivity called the Maunder Minimum. During this period of 70 years, very few sunspots were observed. This coincided with a period of climatic cooling called "the Little Ice Age" during which the climate of the earth cooled noticeably. Though the research is still ongoing, there does seem to be some connection.

Solar Flares

Solar flares are violent explosions in the sun's atmosphere. They contain the equivalent energy of a billion megaton hydrogen bomb, and are the most violent explosion in the solar system. Solar flares and their cousins, Coronal Mass Ejections send out streams of highly energetic particles in the solar winds which interact with and increase the ionization of our atmosphere. In effect, this ionization excites the atmosphere, making it extend farther into space and increasing drag on satellites. This can cause orbital decay, resulting in the satellite burning up in the atmosphere as it descends. Solar flares also produce streams of protons, which pass through our atmosphere and can even pass through a human body, causing biochemical damage. Most proton storms take about 2 hours from the time of first sighting to reach Earth, though at least one in 2005 took only 15 minutes to reach us.

Space Weather

Space weather is considered to be the interaction of solar winds with Earth's magnetic field and our position in the solar system. The plasma of the solar wind also carries an interplanetary magnetic field. Space weather is responsible for a large number of phenomena, from geomagnetic storms to the auroras. Space weather can hinder or cause damage to space operations, as well as wreaking havoc at ground level. Geomagnetically induced currents can cause loss of communications, as well as power outages. The most well known was in Canada in 1989; 6 million people were affected. The particles in geomagnetic storms can damage or cripple spacecraft and satellites, blinding sensors and damaging equipment. Gas and oil pipelines as well as drilling for these products can be affected, as well as undersea communications cables, telephone, and telegraph and railway networks.

Earth and its parent star share a dynamic relationship, which has only just begun to be understood. Research into space weather prediction, solar observations, and sunspot cycle studies and more are still gathering much needed data. With our ever-increasing dependence on information from satellites, electric grids, and power hungry gadgets, it is vital to understand and predict what may be coming our way from our sun.