TY - GEN
T1 - Study of sunspot motion and flow fields associated with solar flares
AU - Wang, Shuo
AU - Liu, Chang
AU - Wang, Haimin
N1 - Funding Information:
We thank Dr. Peter Schuck for providing the DAVE and DAVE4VM codes. We thank Dr. Yang Liu and the HMI team for processing and providing the excellent HMI magne-tograms. The presentation of this paper in the IAU Symposium 273 was made possible due to partial support from the National Science Foundation grants ATM 0548260 and AST 0968672, and NASA Living With a Star grant 09-LWSTRT09-0039.
PY - 2010/8
Y1 - 2010/8
N2 - Evolution of sunspot structure and photospheric magnetic fields are important to understand how the flare energy is built up and released. With high-resolution optical data, it is possible to examine in details the optical flows of the photosphere and their relationship to the flaring process. Using G-band and Stokes-V data obtained with Hinode Solar Optical Telescope (SOT), we study the sunspot motion and flow fields associated with the 2006 December 13 X3.4 flare in NOAA AR 10930. We calculate the centroids of the delta spot umbrae lying in opposite magnetic polarities, and use two different methods to derive the photospheric flow fields of the AR. We find that the shearing motion before the flare changes to unshearing motion associated with the eruption. A decrease of average velocity of shear flow is found to be associated with the flare, with a magnitude of 0.2 km s-1. As a related study, we also test implementing the recently developed differential affine velocity estimator for vector magnetograms (DAVE4VM; Schuck, P. W 2008) technique for the magnetic field observations obtained by the Big Bear Solar Observatory (BBSO) and Helioseismic Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO). Using this method to analyze changes of active region magnetic fields associated with flares may shed new light on the cause and effect of flaring process.
AB - Evolution of sunspot structure and photospheric magnetic fields are important to understand how the flare energy is built up and released. With high-resolution optical data, it is possible to examine in details the optical flows of the photosphere and their relationship to the flaring process. Using G-band and Stokes-V data obtained with Hinode Solar Optical Telescope (SOT), we study the sunspot motion and flow fields associated with the 2006 December 13 X3.4 flare in NOAA AR 10930. We calculate the centroids of the delta spot umbrae lying in opposite magnetic polarities, and use two different methods to derive the photospheric flow fields of the AR. We find that the shearing motion before the flare changes to unshearing motion associated with the eruption. A decrease of average velocity of shear flow is found to be associated with the flare, with a magnitude of 0.2 km s-1. As a related study, we also test implementing the recently developed differential affine velocity estimator for vector magnetograms (DAVE4VM; Schuck, P. W 2008) technique for the magnetic field observations obtained by the Big Bear Solar Observatory (BBSO) and Helioseismic Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO). Using this method to analyze changes of active region magnetic fields associated with flares may shed new light on the cause and effect of flaring process.
KW - Sun: flares
KW - Sun: magnetic fields
KW - Sunspots
UR - http://www.scopus.com/inward/record.url?scp=84882959890&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84882959890&partnerID=8YFLogxK
U2 - 10.1017/S1743921311015663
DO - 10.1017/S1743921311015663
M3 - Conference contribution
AN - SCOPUS:84882959890
SN - 9780521760621
T3 - Proceedings of the International Astronomical Union
SP - 412
EP - 416
BT - The Physics of Sun and Star Spots
A2 - Choudhary, Debi Prasad
A2 - Strassmeier, Klaus
ER -