1. Page 1Hinode4 October 11-15, 2010 Studying Emerging Flux Regions With The SDO Data Yang Liu and HMI Team Stanford University and Other Places yliu@sun.stanford.edu We wish to thank many people who have been making great contribution to the SDO mission!

2. Page 2AGU Fall 13-17, 2010 Emerging Active Regions Understanding emergence of active regions is one of the science objectives that SDO can help to address because: –Full disk measurement can catch very beginning of the emerging; –High cadence can catch the quick procedure of the emerging with great details; –Consistent data quality allows to quantitatively study the evolutionary characteristics of the emerging active regions— minimizing impacts from the data quality.

3. Page 3AGU Fall 13-17, 2010 Emerging active regions AR11066 and AR11069 AR11066 AR11069 Firstly, we chose two emerging active regions, AR11066 and AR11069 for this study.

4. Page 4AGU Fall 13-17, 2010 AR1069 and AR1066 IDDATE & TIME (PEAK)FLARELOCATIONAR 72010/05/04 16:29C3.6N41W231069 102010/05/05 07:20C2.3N41W311069 122010/05/05 11:52C8.8N41W341069 132010/05/05 17:19M1.2N42W361069 172010/05/07 07:42C2.0N40W541069 212010/05/08 04:59C9.3N40W661069 252010/05/08 11:50C1.8N41W701069 272010/05/08 20:11C2.4N41W811069 A flare list during the disk passages of AR11066 and AR11069. Only C-class and above flares are listed here. AR11066 didn’t produce any such flares. If we list all flares (down to B-class), AR11066 produced 2 B-class flares (next table). A question to ask is why?

5. Page 5AGU Fall 13-17, 2010 AR1066 AR1069 IDDATE & TIME (PEAK)FLARELOCATIONAR 12010/05/03 15:04B1.4S26E101066 22010/05/03 21:53B1.0S26E041066 32010/05/04 06:46B1.9N40W221069 42010/05/04 12:09B1.3N41W231069 52010/05/04 12:44B1.7N40W241069 62010/05/04 14:20B2.4N40W221069 72010/05/04 16:29C3.6N41W231069 82010/05/04 19:19B1.1N43W311069 92010/05/05 01:11B1.6N41W271069 102010/05/05 07:20C2.3N41W311069 112010/05/05 08:39B2.4N44W321069 122010/05/05 11:52C8.8N41W341069 132010/05/05 17:19M1.2N42W361069 142010/05/05 18:43B7.3N41W361069 152010/05/05 21:59B1.7N47W431069 162010/05/07 00:34B1.1N40W521069 172010/05/07 07:42C2.0N40W541069 182010/05/07 22:56B4.6N41W621069 192010/05/08 01:04B2.6N40W621069 202010/05/08 03:23B4.3N41W621069 212010/05/08 04:59C9.3N40W661069 222010/05/08 08:52B2.1N40W691069 232010/05/08 09:20B2.1N41W741069 242010/05/08 10:19B3.8N42W701069 252010/05/08 11:50C1.8N41W701069 262010/05/08 18:55B7.2N41W771069 272010/05/08 20:11C2.4N41W811069

6. Page 6AGU Fall 13-17, 2010 Evolution of AR11066 1.The region was at southern hemisphere; 2.Data are 45 sec line-of-sight magnetograms; 3.Data are mapped onto the heliographic center; 4.Line-of-sight field converted to the radial field by assuming the field is purely radial. Evolution characteristics: The active region began to emerge on May 3 00:00 UT, and lasted about 12 hours.

7. Page 7AGU Fall 13-17, 2010 Evolution of AR11069 Evolution characteristics: the active region produced its first C-class flare after 20 hours of dramatic emergence, and took another 14 hours before producing three more C-class (or above) flares. After that activity, the emergence appears to stop, and 36 hours later another C-class flare was produced.

8. Page 8AGU Fall 13-17, 2010 Comparison of AR11066 and AR11069 P1 N1 P1 N P N2 P3 P2 N1 P P2 N2 N3 N N P An outstanding difference between these two regions is the complexity of the magnetic field structure: there are multiple emerging flux regions in AR11069, while only one emerging flux region in AR11066. The positive and negative field patches from different bipoles emerged at the middle of AR11069, and squeezed each other. Those interactiones may lead to the occurrence of the flares.

9. Page 9AGU Fall 13-17, 2010 Another Emerging Active Region-- AR11072 (southern hemisphere) N N P P N P Another emerging active region, AR11072. Only a simple bipole field emerged in this region. No C-class and above flares occurred.

10. Page 10AGU Fall 13-17, 2010 Another Emerging Active Region—AR11076 (southern hemisphere) N Another emerging active region, AR11076. Only a simple bipole field emerged in this region. No C-class and above flares occurred. N N P P P

11. Page 11AGU Fall 13-17, 2010 Another Emerging Active Region—Ar11082 (northern hemisphere) N N Another emerging active region, AR11082. Only a simple bipole field emerged in this region. No C-class and above flares occurred. N P P P

12. Page 12AGU Fall 13-17, 2010 Conclusions We have analyzed several emerging active regions in May-June 2010 with the HMI data. Among these regions, only one produced C-class and above flares. A common property for the non-flaring emerging active regions is that only one simple bipole field emerged in the region. While the flaring-productive active region have multiple bipole fields emerging in the region. The opposite polarity patches from different bipoles emerged at the central area of the region, and squeezed each other. This interaction may lead to the occurrence of the flares. It suggests again that the complexity of the magnetic field structure in an active region is one of the most important factors that determine whether or not an eruption could occur.