Notes: Solar Activity 29.2

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Notes Solar Activity29.2
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I. Intro

• The sun is in constant motion
• Energy produced in the core and gravity combine
  to cause a continuous rising and sinking of gases
• The sun rotates at different rates between the
  poles and the equator, this causes gases to move
  constantly

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II. Sunspots

• Sunspots darker areas of the photosphere that
  are cooler than the surrounding areas
• The suns rotation and movement in the convective
  zone produce magnetic fields
• These fields cause convection to slow in some
  areas, so temperatures are up to 3000 C lower
• These areas appear darker than the area around
  them
• Sunspots occur in cycles that last about 11
  years

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III. Solar Ejections

• Other activities are affected by the sunspot
  cycle.
• The solar-activity cycle is caused by the
  changing solar magnetic field.
• This causes increases and decreases in different
  types of solar activity
•  Solar Ejections events in which the sun emits
  atomic particles. These events include
  prominences, solar flares, and coronal mass
  ejections.

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IV. Prominences

• Prominences loop of relatively cool,
  incandescent gas that extends above the
  photosphere
• Follow curved lines of magnetic force
• May last for a few hours or weeks at a time

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V. Solar Flares

• Solar Flares explosive release of energy that
  is associated with magnetic disturbances on the
  suns surface
• ü      Most violent of all solar disturbances
• ü      The energy is released from sunspot
  magnetic fields
• ü      The loop of gas created can arch 500,000
  km high

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VI. Coronal Mass Ejections

• Coronal Mass Ejections part of the gas from the
  corona that is thrown into space
• ü      As particles reach earths magnetosphere,
  they can cause disturbances in Earths magnetic
  field geomagnetic storms
• ü      These storms can interfere with radio
  communications
• ü      Can also cause power blackouts

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VII. Auroras

• Aurora colored light produced by ions from the
  solar wind that react with the oxygen and
  nitrogen in the upper atmosphere of Earth
• ü      Usually seen close to poles
• ü      Occur between 100 and 1000 km above
  Earths surface
• ü      Most frequent after a peak in the sunspot
  cycle, especially after solar flares occur
• ü      Spacecraft have recorded auroras on
  Jupiter and Saturn

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