Space Weather

AGU Geophysical Monograph 125 2001

• p73 - Solar wind ... - C.T. Russell

  • 400 km/s, 5 electrons and ions per cm³, 5 nT

    • KHL: mass density, 8e-21 kg/m³ ... flux, 3.3e-15 kg/m²-s ... > 1.3 nPa pressure ... > 500μW/m² power

• p91 - Space Weather and the Changing Sun - E.N. Parker

  • Sun core 100,000 km 100g/cm³ 10e7 K

    • ten times brighter than a supernova, only 5e-12 leaks out
    • convection zone 1e-4 of power is upwards kinetic, turns into flares and solar wind

      • 0.2g/cm³ at base, 500,000km

      • 2e-7g/cm² at surface ... temp decline 300 times, pressure decline 3e8 times

• p143 Theory of Coronal Mass Ejections - James A. Klimchuk
  • up to 1e13kg of material, some relativistic
• p173 Gombosi - typical 1e12kg
  • pressure from 2.25 nPa to 4.6 nPa at peak 72 hours later
• IMF = Interplanetary Magnetic Field
• Dst index = deviation of equatorial field, typically 100nT out of 31200nT during storm
  • up to 1000nT, 2200nT/minute

Calculations

• B = 31.2e-6T * (R_E/R)³

• Pressure = Energy density = B^2/2\mu_0 = 3.8e-4 *(R_E/R)⁶ Pa

  • 2.26nPa -> 7.5 R_E, 4.6nPa -> 6.6 R_E