Ionosphere, Magnetosphere and Thermosphere Anthea Coster

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Ionosphere, Magnetosphere and ThermosphereAnthea
Coster

• Topics -
• Magnetospheric-Ionospheric Coupling
• Ion-Neutral Coupling
• Low-Mid-High Latitude Connections
• High Latitude and Polar Processes
• Impacts from Below

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• Magnetospheric-Ionospheric Coupling
• Ionospheric Feedbacks on the Magnetosphere.
• Ionospheric conductivity controls magnetospheric
  processes.
• Transport of heavy ionospheric ions into the
  magnetosphere has long been observed but is
  poorly understood.
• Daytime auroral observations suggest ionospheric
  control of auroral precipitation.
• Fine-scale measurements are critical - AMISR,
  Satellite, Optical.
• Daytime optical measurements.

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• Penetration Electric Fields
• During magnetic storms, the high latitude E-field
  maps down to the equator
• The region 2 field-aligned currents progressively
  shield the low latitudes
• The mechanisms are poorly understood the role of
  dynamo electric fields, conductivity gradients
  other factors has not been properly modelled.
• Ionospheric density and scintillation strongly
  depend on this E-field
• Observations from radars, ionosondes
  magnetometers can provide ground-truth

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• High Latitude Processes
• High-temporal and spatial resolution Total
  Electron Content (TEC) measurements
• Three dimensional ionospheric tomography of
  ionization as well as thermal structures in the
  polar cap ionosphere using ground based ionosonde
  and GPS TEC measurements
• Polar cap boundary measurements using the array
  of photometers
• Coarse information about precipitating particle
  energy in the polar cap ionosphere

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• Heliospheric Impacts
• Studies of the fundamental plasma physical
  processes which mediate energy flow in the
  solar-terrestrial system
• Studies of naturally occurring processes such as
  the structure and dynamics of auroral arcs,
  proton aurora, ionosphere-thermosphere
  interactions, ion outflow and non-Maxwellian
  plasmas are of critical importance

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• Conjugacy
• Global scale auroras are known to be similar, but
  how about mesoscales (L100-1000 km)?.
• ASC images The real conjugate point of a station
  can move hundreds (tens) of km in longitude
  (latitude) during one hour.

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• Ion-Neutral Coupling
• Neutral outflow at high-latitudes occurs when an
  energized out-flowing ion undergoes a
  charge-exchange reaction with a background
  neutral atom.
• Models of the aurora do not include the impact of
  heavy, or light, neutral atoms produced in the
  charge-exchange reactions of energized ions
  out-flowing from the auroral zone.
• Improved understanding of neutral atom impact on
  the magnetosphere.

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• Low-Mid-High Latitude Connections
• Do we really understand the formation of
  medium-scale TIDs
• What is the source of mesoscale ionospheric
  structures at tropical latitudes.

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• Low-Mid-High Latitude Connections
• What are the relative roles of storm-time
  magnetospheric electric fields and dynamo
  electric fields from thermospheric winds driven
  by high latitude heating?
• Do mid-latitude storms have a longitudinal
  dependence perhaps related to the South Atlantic
  Anomaly?
• Is mass transfer from the ionosphere to the
  magnetosphere significant?

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• Low-Mid-High Latitude Connections
• How is plasma transported from the equatorial
  anomalies poleward
• Are mid-latitude ionospheric storms the cause of
  polar cap patches.
• What are the production mechanisms for
  mid-latitude irregularities

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• Impacts from Below
• The response of lower thermosphere (gt100km) to
  stratospheric warming events is not known.
• Wintertime winds and temperatures in the lower
  thermosphere are much more variable than during
  other seasons.
• Tidal signatures before major stratospheric
  warming (LTCS-6, Dec 1991) were vastly different
  from other winter campaigns.
• Pronounced and persistent variability for this
  period was also reported in thermospheric
  parameters in the F-region