Research background and links

On Earth, we had several space weather related power grid outages in the past few decades. More frequent are unexpectedly strong scintilations in the atmosphere causing loss of GPS signals, which means that GPS-guided aircraft landing (e.g. during fog at Heathrow) cannot proceed at the same rate as during clear visibility, causing congestion, but not normally accidents. A very real threat is the possibility of exceeding the annual radiation limits for pregnant women during a solar outburst when on a flight route over the pole. Finally, outside the Earth's orbit, e.g. on a flight to the moon (or elsewhere), astronauts run a very severe risk of suffering radiation from an outburst that would be comparable to that of the fireman on the roof of Chernobyl.

      

Solar Sunspot Cycle

  • The sunspot number varies in an 11 year cycle
  • Caused by the Sun's magnetic field
  • During sunspot maximum flares are frequent
  • Relevance: temporary shutdown of satellites, etc
  • Questions: why 11 years?
  • Explanation: some kind of a dynamo
  • Dynamo: like in a bicycle, but self-excited
  • ...without causing a short circuit
    		•              
  • Facts about ...
  • Space Weather
  • HAO educational
  • NASA: solar physics
  • Why important?
  • Solar dynamo
  • more by J Werne
    •       

    Accretion Discs

  • connected with formation of stars and galaxies
  • as a gas cloud cools, it shrinks, but spins up
  • just like a pirouette dancer
  • discs also in binary stars with mass overflow
    		•              
  • NASA accretion discs
  • Active Galaxies
  • Educational link
    •       

    Galactic Magnetism

  • Observed via synchrotron radiation
  • microgauss field strengths
  • Problem: galaxies are so huge and the field so regular!
  • Also: galaxies have magnetic fields early on (at large redshifts)
    		•              
  • Atlas
    • $Date: 2012-01-20 08:39:59 $, $Author: brandenb $, $Revision: 1.11 $