By Cassidy Clare

Dakota AuringerIsmael Syed

Austin Sandel

WHAT IS A SOLAR FLARE?

A flare is defined as a sudden, rapid, and intense variation in brightness. A solar flare occurs when magnetic energy that has built up in the solar atmosphere is suddenly released. Radiation is emitted across virtually the entire electromagnetic spectrum, from radio waves at the long wavelength end, through optical emission to x-rays and gamma rays at the short wavelength end.

• The energy from the sun comes from nuclear fusion inside of the suns core. The fusion process creates energy by converting nuclear matter into energy. The most common fusion process is the proton-proton chain. This process begins when nuclei of the simplest form of hydrogen are forced together one at a time, then 2 particles form, then 3, and finally 4. The Flares are caused by the rearrangement of the sun’s magnetic field causing the magnetic loops to decrease or increase in pressure.

What Causes a Solar Flare

• The magnetic field is rearranged by the lines that are squeezed past a critical point where it shapes into an 8 then into two 0’s, then the pressure increases to a point of explosion above sun spots. The magnetic loops are the magnetic field lines concentrated around the suns equator in the corona. The magnetic field becomes highly concentrated and increases in strength up to 3000 times normal strength. The energy is then released causing solar flares.

Magnetic Fields

Types of Solar Flares

• In the impulsive flare the energy spectra 0.5-9 MeVnucleon 4He and ~0.5-20 MeVnucleon O, Ne-Si and Fe ions are accelerated in this flare. Normally O, Ne- Si, and Fe ions are accelerated up to energies of ~16 MeVnucleon-1,Si and Fe have higher ionization states in the impulsive flare. Fe is likely to accelerate to at least 16 MeVnucleon and in one case it accelerated to 20-28 MeVnucleon. Electrons and ions are accelerated in and above the ionized coronal region of a magnetic loop. The ions and electrons are in the plasma state meaning that they are highly sensitive to magnetism so when they stream up a magnetic loop they produce the waves in the spectrum. Impulsive Flares are more compact, and in the lower corona. Flares produce hard X-ray burst that are controlled by the amount of time the flare develops. The hard X-rays are due to the bremsstrahlung emission of accelerated electrons.

There are two types of solar flares

Impulsive Gradual•In a gradual solar flare Energetic particles are normally accelerated by a CME-driven shock (Coronal Mass Ejection). CME’s follow the solar cycle and emit the whole spectrum due to their high temperatures (1 million Kelvin). A CME requires a filament of plasma to form in an area of closed magnetic fields and it then ejected. The sun’s magnetic field reverses every 22 years and solar flares occur every 11 years.

Three Stages of a Solar Flare The first stage is the

precursor stage this is where the release of magnetic energy is triggered. Soft X-rays are detected during this stage.

The second stage was the impulsive stage, protons and electrons are accelerated to energies exceeding 1 MeVnucleon. During this stage radio, hard x-rays, gamma rays are emitted.

The third stage is the Decay stage, this is where the soft X-rays decay.

Sun Spots Effect on Solar Flares

Sun spots occur because in some places the magnetic field cools and slows down the radiation forming a Sun Spot. Sunspots usually form in pairs of the reverse polarity. Sun spots are essential in the flare process because when sun spots of the reverse polarity collide the particles are accelerated and explode resulting in a solar Flare.

How Solar Flares Affect Us

Solar Flares emit harmful rays throughout the spectrum. Most of these rays are blocked by our magnetosphere but the radio waves break through. These rays can disrupt our communications and cause global blackouts.

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• Solar Atmosphere- The outermost gaseous layers of a planet, natural satellite, or star.

• Corona-type of plasma “atmosphere" of the sun or other celestial body, extending millions of kilometers into space, most easily seen during a total solar eclipse.

• MeVnucleon-1-1,000,000 electron volts.• Bremsstrahlung- emission of accelerated electrons, when

electromagnetic radiation is produced by a change in the velocity of an electrically charged subatomic particle such as an electron, as when it collides with another object.

Vocabulary