What Studies Have Been Done What Studies Have Been Done About AR 10930 ?About AR 10930 ?

Presented by Sung-Hong Park

NJIT / SWRL

11-Dec-2009 SWRL Group Meeting 2

Published Papers ( more than Published Papers ( more than 2727 ) )

SubjectSubject AuthorAuthor

Pre-Flare or Pre-Flare or

Flare RelatedFlare Related

Sunspot Rotation/Motion Min et al. (SoPh/2009), Su et al. (SoPh/2008), Wang et al. (ApJ/2008), Yan et al. (RAA/2009), Zhang et al. (ApJ/2007)

Filament Rotation Williams et al. (PASJ/2009)

Photospheric Flow Tan et al. (ApJ/2009), Gosain et al. (ApJ Letter/to be submitted)

Magnetic Field Line Configuration Changes

(e.g. Shear/Inclination Angle)

Guo et al. (ApJ/2008), Jing et al. (ApJ/2008b), Kubo et al. (PASJ/2007), Minoshima et al. (ApJ/2009)

Electric Current Minoshima et al. (ApJ/2009), Schrijver et al. (ApJ/2008), Wang et al. (ApJ/2008)

Flare Ribbon

& Reconnection Rate

Jing et al. (ApJ/2008a), Li et al. (A&A/2009)

Magnetic Free Energy Guo et al. (ApJ/2008)

Magnetic/Current Helicity Magara & Tsuneta (PASJ/2008), Su et al. (ApJ/2009), Zhang et al. (ApJ/2008)

Intermittency Abramenko et al. (ApJ/2008)

Coronal Nonthermal Velocity

Harra et al. (ApJ/2009)

11-Dec-2009 SWRL Group Meeting 3

Published Papers ( Published Papers ( continuedcontinued ) )

SubjectSubject AuthorAuthor

Pre-Flare or Pre-Flare or

Flare RelatedFlare Related

White-Light Flare Isobe et al. (ApJ/2007), Wang (RAA/2009)

Radio Emission Kaufmann et al. (SoPh/2009), Minoshima et al. (ApJ/2009)

Sheared SXR Loop Su et al. (PASJ/2007),

HXR Emission Minoshima et al. (ApJ/2009)

CME RelatedCME Related

EIT wave, Coronal Dimming, & Outflows

Jin et al. (ApJ/2009)

X-ray plasmoid ejection

& MHD shock wave

Asai et al. (ApJ/2008)

Interplanetary Interplanetary Space RelatedSpace Related

SEP Acceleration Origin Li el al. (A&A/2009), Liu et al. (ApJ//2008)

MC Reconstruction Liu et al. (ApJ//2008)

11-Dec-2009 SWRL Group Meeting 4

Overview of NOAA 10930Overview of NOAA 10930

LASCO/C2LASCO/C2

Hinode/FG/Ca II HHinode/FG/G-bandHinode/FG/Stokes-V

Hinode/XRT LASCO/C2Hinode/EIS BBSO/H-alpha

11-Dec-2009 SWRL Group Meeting 5

a) Min et al. (ApJ/2009)1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

Non-linear Affine Velocity Estimator (NAVE)

technique by Chae & Sakurai (2008) was used

to measure apparent motions from the co-

aligned images.

Hinode/FG/G-band

= 0.22km/s

Radius (arcsec)

Azimuth Angle (deg)

Date (day)

Summary

i) The small sunspot of positive polarity rotated counterclockwise about its center by 540° during the period of five days.

ii) Its angular velocity varied with the azimuth angle as well as the radial distance, being affected by the asymmetric shape of the umbra.

iii) The angular velocity increased up to 8° h-1 until 13 December as the sunspot grew, and then decreased rapidly down to 3° h-1 on the next day as the sunspot decayed.

iv) The coronal loops that connected the two sunspots became sigmoidal in shape.

v) The coronal emissions (Hinode/EIS Fe XII) from the regions around the rotating sunspot were blueshifted, which may indicate the expansion of the coronal loops.

vi) Our results suggest that the rotation of the sunspot may be closely related to the dynamic development of emerging twisted magnetic fields.

11-Dec-2009 SWRL Group Meeting 6

b) Yan et al. (RAA/2009)1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

Hinode/SOT/SP Continuum

Hinode/SOT/SP/ Vector Magnetogram

11-Dec-2009 SWRL Group Meeting 7

c) Zhang et al. (SoPh/2009)1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

= 0.22km/s

MDI

TRACE cont. TRACE 195Å

TRACE 1600Å

Summary

i) From December 11 at 12:51 UT, we find that the opposite polarities of ephemeral regions (ERs) emerge along the neutral line of AR 10930.

ii) ERs are ellipses in shape and separate each other with a speed of 0.5 km/s.

iii) The interaction between ephemeral regions and fast rotation of a sunspot plays a decisive role in producing the global instability responsible for this major solar event.

11-Dec-2009 SWRL Group Meeting 8

d) Wang et al. (ApJ/2008)1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

= 0.22km/s

Large-scale sunspot motion (center-of-mass separation) associated with the flare

Shear

ConvergingDiverging

Converging

De-Shear

11-Dec-2009 SWRL Group Meeting 9

Comparison with Coronal Magnetic Helicity1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

= 0.22km/s

11-Dec-2009 SWRL Group Meeting 10

e) Su et al. (SoPh/2008)1. Sunspot Rotation/Motion1. Sunspot Rotation/Motion

Lorentz force at the photospheric surface in an untwisted Sunspot Model (Parker, 1979)

Non-Potential Magnetic Stress (NPMS)

Derived from the potential field

11-Dec-2009 SWRL Group Meeting 11

a) Williams et al. (PASJ/2009)2. Filament Rotation2. Filament Rotation

EUV spectroscopic observations of an AR filament before the X4.3 flare in the He II (256.32Å) line

Summary

i) We measure Doppler shifts with apparent velocities of up to 20 km/s, which are antisymmetric about the filament axis and occur several minutes before the flare’s impulsive phase.

ii) This is indicative of a rotation of the filament, which is in turn consistent with expansion of a twisted flux rope due to the MHD helical kink instability.

11-Dec-2009 SWRL Group Meeting 12

a) Tan et al. (ApJ/2009)3. Photospheric Flow3. Photospheric Flow

Penumbral flow derived from the LCT velocity of G-band images

A1 A2

Shear flow derived from the LCT velocity of G-band images with overlapped Stokes –V images to distinguish the positive and negative polarities

11-Dec-2009 SWRL Group Meeting 13

a) Kubo et al. (PASJ/2007)4. Magnetic Field Line Configuration Changes4. Magnetic Field Line Configuration Changes

with respect to the line-of-sight

χχ => c => cos (2os (2χχ))E-W (0° or 180°)

N-S (90° or 270°)

Related to a trigger mechanism ?

11-Dec-2009 SWRL Group Meeting 14

b) Jing et al. (ApJ/2008b)4. Magnetic Field Line Configuration Changes4. Magnetic Field Line Configuration Changes

Magnetic shear is defined as the azimuth difference between the extrapolated NLFF field and the potential field.

11-Dec-2009 SWRL Group Meeting 15

c) Guo et al. (ApJ/2008)

4. Magnetic Field Line Configuration Changes & 4. Magnetic Field Line Configuration Changes & 7. Magnetic Free Energy7. Magnetic Free Energy

Free Energy

Shear Angle

11-Dec-2009 SWRL Group Meeting 16

d) Minoshima et al. (ApJ/2009)4. Magnetic Field Line Configuration Changes4. Magnetic Field Line Configuration Changes

HXR sources are located where the change of direction of the horizontal magnetic fields is the most clearly seen.

11-Dec-2009 SWRL Group Meeting 17

a) Wang et al. (ApJ/2008)5. Electric Current5. Electric Current

Absolute value of electric current density in the channel structure at 12:00 UT on December 13

11-Dec-2009 SWRL Group Meeting 18

b) Schrijver et al. (ApJ/2008)5. Electric Current5. Electric Current

Before

After

Before After

|jz| |jz|

|jt| |jt|

jz jz

11-Dec-2009 SWRL Group Meeting 19

a) Jing et al. (ApJ/2008a)6. Flare Ribbon & Reconnection Rate6. Flare Ribbon & Reconnection Rate

Vr : ribbon separation-velocity, Bn : the normal component of the local magnetic field strength measured in the ribbon location, dl : the length along the ribbons, da : the newly brightened area swept by the ribbons

1. Quantitative Estimate of the Coronal Magnetic Reconnection Rate in the Reconnecting Current Sheet (Forbes & Priest 1984 and Qiu et al. 2002)

2. Electric Field at the Reconnecting X-point

3. Magnetic Energy Release Rate (Isobe et al. 2002)

11-Dec-2009 SWRL Group Meeting 20

a) Li et al. (A&A/2009)6. Flare Ribbon & Reconnection Rate6. Flare Ribbon & Reconnection Rate

Vr : ribbon separation-velocity, Bn : the normal component of the local magnetic field strength measured in the ribbon location, dl : the length along the ribbons, da : the newly brightened area swept by the ribbons

1. Quantitative Estimate of the Coronal Magnetic Reconnection Rate in the Reconnecting Current Sheet (Forbes & Priest 1984 and Qiu et al. 2002)

11-Dec-2009 SWRL Group Meeting 21

a) Zhang et al. (ApJ/2008)8. Magnetic/Current Helicity8. Magnetic/Current Helicity

Summaryi) We find that there is a sharp jump of dH/dt around the onset and quench of a microwave burst at a frequency of 2.84 GHz: the rate of dH/dt changes from negative to positive around the start of the eruption and recovers to negative when the eruption stopped.ii) Furthermore, the temporal profile of dH/dt is consistent with that of a microwave burst. These results indicate that sharp variations of dH/dt are closely related to the solar eruption.

Reversal Effect ?? or Real Helicity Sign Change ??Hartkorn & Wang (2004) have pointed out that the reversal effect that can disturb MDI magnetic field measurements may also lead toimpulsive changes of dH/dt during the flaring time.

11-Dec-2009 SWRL Group Meeting 22

b) Magara & Tsuneta (PASJ/2008)8. Magnetic/Current Helicity8. Magnetic/Current Helicity

Self-Consistent Shear Flow based on “Flux-Emergence Model”

Magnetic Helicity injected via shear motions of a uniformly sheared arcade with the size of L and a flux of Φ

11-Dec-2009 SWRL Group Meeting 23

c) Su et al. (ApJ/2009)8. Magnetic/Current Helicity8. Magnetic/Current Helicity

Summaryi) The patches of positive and negative helicities were intermixed showing a mesh pattern in the umbra and a thread pattern in the penumbra.ii) For its main stable sunspot (MSS), there was a positive-helicity patch accounting for 43% ∼of the umbra area surrounding the inner umbra, which had a predominantly negative helicity. For its minor rotating sunspot (MRS), there was a negative-helicity patch appearing in the umbra.iii) The fine distributions of αz and hc on a penumbral filament indicated that it may be possiblefor the two opposite helicities to coexist in a filament and their magnitudes were nearly equivalent.

A proxy of the local twist of the magnetic field

z-component of the current helicity density

α hc

α hcBt

11-Dec-2009 SWRL Group Meeting 24

a) Abramenko et al. (ApJ/2008)9. Intermittency9. Intermittency

Structure Function (Frisch 1995)

Flatness Function

In the spatial domain, intermittency index ĸ implies a tendency of the magnetic field to concentrate into small-scale flux tubes of high intensity, surrounded by extended areas of much weaker field. In the temporal domain, intermittency is evidencedthrough a burstlike behavior of events.

Kinetic vorticity

|ω2| characterizes the dissipation rate of kinetic energy in the photosphere caused by random motions of the footpoints of magnetic flux tubes.

SOT/FG

XRT

GOES

NoRH

Summaryi) The intermittency of the photospheric magnetic field peaked after the specific kinetic vorticity of plasma flows in the active region reached its maximum (4 hr time delay).ii) A gradual increase of coronal intermittency occurred after the peak of the photospheric intermittency.iii) The time delay between the peak of photospheric intermittency and the occurrence of the first strong (X3.4) flare was approximately 1.3 days.iv) Our analysis seems to suggest that the enhancement of intermittency/complexity first occurs in the photosphere and is later transported toward the corona.

11-Dec-2009 SWRL Group Meeting 25

a) Harra et al. (ApJ/2009)10. Coronal Nonthermal Velocity10. Coronal Nonthermal Velocity

Vnt

EIS Fe XII

11-Dec-2009 SWRL Group Meeting 26

a) Isobe et al. (ApJ/2007)12. White-Light Flare12. White-Light Flare

Summaryi) Assuming that the leading edge (kernels) was heated directly by nonthermal particles beams, and the diffuse parts were heated heating by radiative back-warming, We found that the layer of diffuse emission is about 100km below the height of the irradiation source. ii) Our result indicates that the height of the diffuse component, which we believe to be due to radiative back-warming, is also in the upper or middle chromosphere as that of the irradiation source.

11-Dec-2009 SWRL Group Meeting 27

b) Wang et al. (RAA/2009)12. White-Light Flare12. White-Light Flare

Summaryi) We found that the cut-off visibility is likely around M1 flares under the Hinode observing conditions.ii) WLF kernels are found inside sunspots. No kernel in the quiet areas of the sun was detected.iii) We speculate that the disk position of flares affects the visibility of WLFs. The events closer to the limb would have a better chance to have observed whitelight emissions, consistent with the comparison of Xu et al. (2006).

Peak ContrastIo is the local intensity before the flare and I is the intensity at the observed peak of the flare. The pre-flare image is taken between 2 to 4 minutes before the time of the flare peak.

The equivalent area is the contrast integrated over the flare area, in units of arcsec2.

Data samples observed by Jess et al. (2008)

11-Dec-2009 SWRL Group Meeting 28

a) Kaufmann et al. (SoPh/2009)13. Radio Emission13. Radio Emission

2006 December 6

Summaryi) The sub-THz impulsive component had its closer temporal counterpart only in the higher energy X- and γ-rays ranges.ii) The spatial positions of the centers of emission at 212 GHz for the first flux enhancement were clearly displaced by more than one arcminute from positions at the following phases.iii) The observed sub-THz fluxes and burst source plasma parameters were found difficult to be reconciled to a purely thermal emission component.

11-Dec-2009 SWRL Group Meeting 29

a) Minoshima. (SoPh/2009)13. Radio Emission & 15. HXR Emission13. Radio Emission & 15. HXR Emission

Summaryi) Microwave images taken with the Nobeyama Radioheliograph show a loop structure connecting the HXR footpoint sources.ii) The brighter parts of the microwave intensity are located between the top and footpoints of the loop.iii) We consider these observations as evidence of electron acceleration near the magnetic separatrix and injection parallel to the field line.

2006 December 13

NoRH 34 GHz

RHESSI 35-100keV

Right (tick contours) and Left (dashed contours) Circular Polarization

NoRH 34 GHz Negative image

11-Dec-2009 SWRL Group Meeting 30

a) Su et al. (PASJ/2007)14. Sheared SXR loop14. Sheared SXR loop

2006 December 13 Pre-Flare vs. Post-Flare

Summaryi) XRT had detected two loop eruptions (likely filament eruptions), which started around 16:28 and21:58 UT on December 12, respectively.ii) The magnetic configuration after the second loop eruption and 14 minutes prior to the December 13 flare is displayed in figure 4b, which is composed of several highly sheared loops.iii) After the December 13 flare onset, the post-flare loops gradually propagated from the highly sheared core field region to the outer and less-sheared envelope field regioniv) Corresponding to the sheared core field observed by XRT, a filament is seen in TRACE prior to the December 13 flare (figure 4e). We still see most parts of the filament after the flare, as can be seen in figure 4f.

2006 December 14 Pre-Flare vs. Post-Flare

Summaryi) A filament eruption occurred around 16:40 UT on December 14.ii) A comparison of the figures shows that the filament corresponds to a highly sheared X-ray loop.iii) Figure 5b shows an X-ray image after the filament eruption and 30 minutes before the December 14 flare. We see no significant changes in the magnetic configuration before and after the filament eruption.iv) Similar to the December 13 flare, the post-flare magnetic configuration of the December 14 flare shows a highly sheared inside and less sheared outside structure (figure 5c)