Sunspot Research Paper

Sunspots are dark areas on the solar surface that contain transient and concentrated magnetic fields. They are the most prominent visible features on the photosphere Sun; a moderate-sized sunspot is about as large as Earth. Sunspots form and dissipate over periods of days or weeks. They occur when strong magnetic fields emerge through the solar surface and allow the area to cool slightly, from a background value of 6000 degrees C down to about 4200 degrees C; this area appears as a dark spot in contrast with the Sun. The darkest area at the centre of a sunspot is called the umbra; it is here that the magnetic field strengths are the highest. The less dark, striated area around the umbra is called the penumbra. Sunspots rotate with the solar surface, taking about 27 days to make a complete rotation as seen from Earth. Sunspots near the Sun's equator rotate at a faster rate than those near the solar poles. Groups of sunspots, especially those with complex magnetic field configurations, are often the sites of flares.

Sunspot activity has been observed since the time of Galileo in 1610, with detailed records kept for over 200 years by specialist solar observatories. The temperature within sunspots is about 4,600 K, and there appears to be a sunspot cycle that peaks every 11.1 years.
When sunspots occur, they can interfere with the terrestrial plasma environment, causing magnetic sub-storms, auroral activity, power outages and influencing everything from telecommunications to the electrical power grid.
As they near Earth, the magnetic storm compresses the bow wave of the magnetosphere and the auroras rage as particles penetrate the field's defences at their lowest points near the poles and spiral around the Earth's lines of force back and forth between the magnetic poles. The ring current running around the Earth in the ionosphere and Van Allen Belts increases causing difficulties in radio communications which rely on reflection off the
ionosphere.

Disrupted Radio Communications.

Many communication systems utilize the ionosphere to reflect radio signals over long distances. Ionospheric storms can affect radio communication anywhere at all. Some radio frequencies are absorbed and others are reflected, leading to rapidly fluctuating signals and unexpected propagation paths. TV and commercial radio stations are less affected by solar activity, but other radio such as ground-to-air, ship-to-shore, Voice of America, Radio Free Europe, and amateur radio are frequently disrupted. Radio operators using high frequencies rely upon solar and geomagnetic alerts to keep their communication circuits up and running.

Disrupted Satellites.

Geomagnetic storms and increased solar ultraviolet emission heat Earth's upper atmosphere, causing it to expand. The heated air rises, and the density at the orbit of satellites up to about 1000 km increases significantly. This results in increased drag on satellites in space, causing them to slow and change orbit slightly. Unless low-Earth-orbit satellites are routinely boosted to higher orbits, they slowly fall, and eventually burn up in Earth's atmosphere.

Hazards to Humans.

Intense solar flares release very-high-energy particles that can be as injurious to humans as the low-energy radiation from nuclear blasts. Earth's atmosphere and magnetosphere allow adequate protection for us on the ground, but astronauts in space are subject to potentially lethal dosages of radiation. The penetration of high-energy particles into living cells, measured as radiation dose, leads to chromosome damage and, potentially, cancer. Large doses can be fatal immediately. In October 1989, the Sun produced enough energetic particles that an astronaut on the Moon, wearing only a space suit and caught out in the brunt of the storm, would probably have died. (Astronauts who had time to gain safety in a shelter beneath moon soil would have absorbed only slight amounts of radiation.)