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