2 L3 Comms, NASA GSFC, USA

1
Chromospheric Heating in the Quiet Sun
James McAteer1 Supervisors Dr. M.
Mathioudakis1, Prof. F.P.Keenan1 Dr P. Gallagher
2, Dr. D.R.Williams 3, Shaun Bloomfield 1
2 L-3 Comms, NASA GSFC, USA
3Mullard Space Science Laboratory, Surrey, UK
2
Problem?

• Thermal
• Radiative
• Mechanical, Electrical, Magnetic

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MHD Waves

• Assume no gravity, perfectly conducting,
  compressible, uniform gas in an inhomogenous
  magnetic field

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Solutions?

• Active Regions / Flares
• lt 1 energy input
• Internetwork Bright Grains
• lt 1 energy input

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Quiet Sun Magnetic Network
Magnetism is to astrophysicists what sex is to
psychoanalysts Henk van de Hulst
If the Sun did not have a magnetic field, it
would be as uninteresting a star as most night
time observers believe it to be- R. Leighton
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1) Radial Study
McAteer et al., (2002), ApJ, 587, L165
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Wavelet Analysis

• (A) no time localisation
• (b) no frequency localisation

• Many time series exhibit non-stationary behaviour

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2) Temporal Study

• Quasi-periodic oscillations
• Wavelet Analysis
• Granular Buffeting
• Wave Packets

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3) Propagating Waves

• Correlate power curves
• Ca II K3
• H? core
• Mg I b2
• Mg I b1 - 0.4Å
• Time lag at maximum correlation

McAteer et al., (2003), ApJ, 567, in press
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MHD Mode Coupling
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Future

• Higher cadence, longer timespan, larger field of
  view
• Relation to magnetic field strength
• Frequency, duration amplitude of oscillation
• Height of coupling
• How many NBPs
• How often does mode-coupling occur? 1 per NBP?
• What are the rest of the waves doing
• Downward moving waves
• Very fast very slow speeds
• What happens in Transition region and Corona?

email J.mcateer_at_qub.ac.uk http//star.pst.qub.ac
.uk/jma/