updates on measurements of the wavefunctions of solar acoustic waves scattered by sunspot
DESCRIPTION
Updates on Measurements of the Wavefunctions of Solar Acoustic Waves Scattered by Sunspot. Hui Zhao 1 Collaborators: Dean-Yi Chou 2 Ming-Hsu Yang 2 Zhi-Chao Liang 2. 1 National Astronomical Observatory, Chinese Academy of Sciences. 2 National Tsing Hua University, Taiwan. - PowerPoint PPT PresentationTRANSCRIPT
Updates on Measurements of the Wavefunctions of Solar Acoustic Waves Scattered by
Sunspot
Hui Zhao1
Collaborators:Dean-Yi Chou2
Ming-Hsu Yang2
Zhi-Chao Liang2
1National Astronomical Observatory, Chinese Academy of Sciences
NAOC, 25 August 2012
2National Tsing Hua University, Taiwan
The interaction of the acoustic waves with the magnetic region : Two views
a. The incident wave is modified as it enters the magnetic region. This modification in the wave inside the magnetic region yields a change in the wave around the magnetic region.
b. The magnetic region generates a scattered wave as the incident wave perturbs the magnetic region. This scattered wave is added to the incident wave to yield the total wave in and around the magnetic region.
Equations for Interaction of Waves with Magnetic Regions Equations for Interaction of Waves with Magnetic Regions
quiet Sun
magnetic region
where S is the source describing the interaction.
Solve the inhomogeneous equation:
Need an incident wave propagating toward of the sunspot.
The conceptually simplest incident wave is the one propagating horizontally in a certain direction.
Cameron, Gizon & Duvall (2008)Cameron, Gizon & Duvall (2008)
2. The incident wave is the line-averaged 2. The incident wave is the line-averaged signal, which is a plane wave packet. signal, which is a plane wave packet.
3. Cross-correlation between the 3. Cross-correlation between the reference line and each pointreference line and each point
1. Signals on a ridge (fixed n) are 1. Signals on a ridge (fixed n) are isolated to obtain horizontal waves. isolated to obtain horizontal waves.
The cross-correlation function relates to the wave function, but is not the wave function!!!
denominator
NOAA 11084: 29 June – 5 July 2010 (12,402 frames)NOAA 11092: 30 July – 7 August 2010 (13,616 frames)
DATADATA : : NOAAs NOAAs 11084 11092 11084 11092 (HMI) (HMI)
Stable
axisymmetric
Clean around
CCF vs. Wave Function
AR11092
p2 modes
Different :
Amplitude
Phase
Width
Dispersion
Incident Waves, Total Wave, Scattered WaveIncident Waves, Total Wave, Scattered Wave
Scattered wave : p2 modes
The curvature of AR11084 is greater than that of AR11092
Scattered wave : f modes
Have No obviously curvature
Scattered wave : p5 modes
The curvature of p5 modes is greater than that of p2 modes
Updated results• Phase speed filter
Phase speed filter : l=300
Phase speed filter : l=200
Updated resultsScattering from n to n’
f
p1p2
p3p4p5
…
Scatter wave : p2 to p1 and p3
Mode Conversion
• Scattering : n n (n, kx, ky) (n, kx’, ky’)
ω does not change. (kx2+ky2=kx’2+ky’2) k changes direction.• Scattering : n n’ (n, kx, ky) (n’, kx’, ky’) ω does not change. |k| changes.
The End
Direction filter
AR11084, p2 modes, time=0 / plot : reference line