Space Weather
Space weather is a complex series of events
that begin deep inside the Sun, and extend
throughout the solar system, carried by the
solar wind. Most of this weather is both
invisible and benign, but occasional severe
storms can shake the Earth's magnetic field
and spawn aurora, electrical power blackouts
and satellite outages.
http://sunearth.gsfc.nasa.gov/sechtml/tut.html
The Solar Interior
Solar Interior Picture
Solar Interior Facts
• In core 600 million tons of matter turn
into energy every second
• Fusion: H+H = He + Energy
• Layers:
– Core - fusion
– Radiative Zone
– Convection Zone
– Photosphere - surface
– Chromosphere - color
– Corona – invisible expect during solar
eclipse
Sunspots
Sunspots Picture
Sunspots Facts
• Intense magnetic energy nearly 4000 times
stronger than the Earth's own field.
• In Sun's convective zone, jet streams of
flowing currents are made.
• Ends of magnetism ropes come to surface as
2 spots.
• 2 spots with opposite poles.
Solar Activity Cycle
Solar Activity Cycle Picture
Solar Activity Cycle Facts
• Space weather comes in 11-year cycles.
• Solar activity cycle = the sunspot cycle.
• During sunspots, sun is brighter –
magnetism keeps gas from leaving
surface.
Solar Flares
Solar Flares Picture
Solar Flares Facts
• Powerful releases of magnetic energy.
• Groups of sunspots collide.
• Currents of flowing gas moving in opposite
directions.
• Sunspots and the gases around them flow at
thousands of miles a minute.
• In few minutes, goes from a minor to major
explosion of energy.
Corona
Corona Picture
Corona Facts
• Sun ejects billions of tons of gas.
• Speed = millions of miles per hour through
solar system.
• Coronal mass ejections = CMEs
• Size = millions of kilometers, big pinwheel
pattern, beyond Pluto.
• Little or no harm expected.
Solar Winds
Solar Wind Picture
Solar Wind Facts
• Steady breeze from the Sun.
• Corona is not stable; leaking into space.
• Magnetic loops heat gases to 1,000,000
degrees.
• Reaches out to solar system.
– Affect planets’ atmospheres & magnetic fields.
– Venus & Mars lose some atmosphere.
– Earth, Jupiter, Saturn, Uranus & Neptune have
magnet shields to protect.
Magnetosphere
Magnetosphere Picture
Magnetosphere Facts
• Invisible cloak of magnetism protects Earth.
• Lines of magnetic force loop from inside
Earth into space.
• Returns back in a great closed circuit.
• If there were no Sun or solar wind, the
Earth's magnetic field would extend far
beyond the orbit of the moon for millions of
miles.
Plasma Clouds
Plasma Clouds Picture
Plasma Clouds Facts
• Flows from the atmosphere or trapped from the
solar wind.
• Can be lethal to astronauts.
• Regions of space where powerful flows of
particles exist
• The Earth's magnetic field is so strong -
plasmasphere pulled along as Earth spins.
• During bad coronal mass ejections, atoms
atmosphere are pumped into the plasmasphere =
polar fountain.
Ionosphere
Ionosphere Picture
Ionosphere Facts
• Ionosphere: A layer of charged particles
surrounding the Earth.
• Act like an invisible mirror to radio waves-
reflects.
• Ionosphere is connected to the ground by
thunder storm clouds.
• Radio signals 'twinkle' like stars called radio
scintillation.
Aurora Borealis
Aurora Borealis Picture
Aurora Borealis Facts
• Curtains of colored light signal a turn for
the worst in space weather
• Aurora produced by flows of charged
particles entering the atmosphere.
• Matches the sunspot cycle
• Colors = excited oxygen and nitrogen atoms