To understand solar flares we must understand how the Sun works.
The Sun is a giant fusion reactor. The core of the Sun is 27 MILLION degrees fahrenheit, partly due to the giant pressure created by the gravity pulling all the mass to the center. At this extreme temperature and pressure the process of fusion can take place. Fusion, or the process of combining two separate things into one, is not only what lights up the Sun but also gives the Earth light and heat. To put it plainly two hydrogen atoms are fused to create one helium atom. The helium atoms are less massive than the two hydrogen atoms that began the process; because of this, according to Einstein’s theory of relativity, the loss of mass means that it has to be converted to energy (E=mc2). The energy created by this process is emitted as many forms of light: ultraviolet, X-rays, infrared, visible, radio waves, and microwaves.
The core of the Sun is so dense that it takes energy created by fusion anywhere from 100,000 years to 50 million years to reach the SURFACE of the sun. From that point on it only takes 8 MINUTES to reach the Earth.
We have to start with the solar atmosphere, or the atmosphere of the Sun. The Sun’s atmosphere is actually a giant magnetic hodgepodge of energy and power. It is said to be made up of the Chromosphere, Photosphere, and Corona. See the image below to better understand the Sun’s layers.
Look at the animation below of a CME taking place. The large disk in the middle is used to block out the Sun so the Corona is visible.
Solar Flares:
Solar flares occur when large amounts of energy explode in the solar atmosphere and heat the surrounding area to millions of degrees. This process may take a few seconds or a few minutes. Flares have the energy equivalent of 160,000,000 megatons of TNT. They accelerate particles into space and appear to us as bright lights on the surface of the Sun. When these flares are directed toward Earth we usually receive the energy in a couple days. Solar flares are classified based on their x-ray intensity. A, B, C, M, X are the classifications. The latest flare is an X-class flare, the largest.
Solar flares typically occur near sunspots, or areas of the sun that are cooler. Since the sunspots are cooler the magnetic field is concentrated to those areas causing the Sun to become unstable. Solar flares move near the speed of light and Earth has little time to prepare for their arrival. Astronauts are bombarded with increased radiation when these events occur because they do not have a magnetic field to protect them like the Earth does. See the image below for a representation of a solar flare.
Power systems: widespread voltage control problems and protective system problems can occur, some grid systems may experience complete collapse or blackouts. Transformers may experience damage.
Spacecraft operations: may experience extensive surface charging, problems with orientation, uplink/downlink and tracking satellites.
Other systems: pipeline currents can reach hundreds of amps, HF (high frequency) radio propagation may be impossible in many areas for one to two days, satellite navigation may be degraded for days, low-frequency radio navigation can be out for hours, and aurora has been seen as low as Florida and southern Texas (typically 40° geomagnetic lat.)**.
Each geomagnetic storm has its own classification and power. To see the other levels of the scale please visit: http://www.swpc.noaa.gov/NOAAscales/ I feel like we should review before I wrap this up considering how complex this blog is:
- The Sun creates heat and light in its core through the process of fusion.
- It takes 100,000-50,000,000 years for the light to reach the surface of the sun.
- The light takes 8 minutes to reach Earth.
- When large amounts of energy explode from the Sun this is called a solar flare.
- Solar flare energy moves near the speed of light to Earth and arrives in minutes.
- Many times solar flares lead to CME's, which are large explosions of charged particles.
- These CME's follow the solar wind and bombard the Earth to create aurora.
- Aurora are pretty to look at but can be dangerous. Blackouts are possible when large amounts of radiation hit the Earth.
Sources:
- http://sunearthday.gsfc.nasa.gov/2007/locations/ttt_sunlight.php
- http://hesperia.gsfc.nasa.gov/sftheory/flare.htm
- http://www.enchantedlearning.com/subjects/astronomy/sun/prominences.shtml
- http://image.gsfc.nasa.gov/poetry//workbook/page6.html
- http://cse.ssl.berkeley.edu/coronalweather/CMEsFlares/index.html
- http://www.swpc.noaa.gov