Schumann Resonance from Earth to Titan

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Schumann Resonance from Earth to Titan

• Dana Ionita
• School of Earth Atmospheric Sciences
• Georgia Institute of Technology

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Outline

• Definition
• Earth
• cavity dimensions properties
• Titan (properties)
• Huygens probe (observations)
• cavity dimensions properties (a bit more
  complex)
• energy source ??? possibilities
• liquid ocean
• Conclusion 2 big questions about Titan

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Schumann waves

• Resonance waves of the atmospheric cavity formed
  between the Earths surface and ionosphere, two
  conductive surfaces with a non-conductive
  atmosphere

Simoes et al. (2007)
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Earth

• Dimensions properties
• Surface conductivity (s) 0.01 (land) and 1
  (sea) S m-1
• Frequencies (obs) 7.8, 14, 20, 26, 33, 39, 45
  Hz (/- 0.5 Hz daily)
• Cavity height (h) 100 km
• Radius (Rp) 6378 km
• Skin depth (d) 0 km
• Energy source lightning

Siingh et al. (2006)
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Titan

• Cavity properties
• Ionosphere at 1,200 km, 63 km
• h (s 10-3 S m-1) 750 km
• Surface conductivity (s) 10-10 S m-1
• Radius (Rp) 2575 km
• Skin depth (d) 100 km

Simoes et al. (2008)
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Frequencies on Titan

• Huygens (Jan 14, 2005) observed 36 Hz ELF wave
• Instrumentation noise most likely ruled out as
  source
• Model results 13.43 (19.15), 28.13 (34.32),
  43.93 (49.48) Hz

Beghin et al (2007)
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Energy source ???

• Lightning not observed, but not ruled out
• Titan ionosphere motion of Saturns
  magnetosphere

Blanc et al (2002)
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Titans liquid ocean
Sotin Tobie (2008)

• Titan is believed to have an underground liquid
  water layer
• Modeling of Titan cavity ? shape size of cavity
  ? depth of underground liquid water surface

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Further Work

• 2 questions about Schumann resonance at Titan
• Energy source
• - faint lightning possible, not observed
• - interactions with Saturns magnetosphere need
  to be better understood
• Depth of liquid ocean
• - the cavity properties can be relatively well
  constrained in a model

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• Thank you.
• Any Questions?