Page 1 Hinode4 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!

Page 2 AGU 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.

Page 3 AGU 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.

Page 4 AGU Fall 13-17, 2010

AR1069 and AR1066

ID DATE & TIME (PEAK) FLARE LOCATION AR

7 2010/05/04 16:29 C3.6 N41W23 1069

10 2010/05/05 07:20 C2.3 N41W31 1069

12 2010/05/05 11:52 C8.8 N41W34 1069

13 2010/05/05 17:19 M1.2 N42W36 1069

17 2010/05/07 07:42 C2.0 N40W54 1069

21 2010/05/08 04:59 C9.3 N40W66 1069

25 2010/05/08 11:50 C1.8 N41W70 1069

27 2010/05/08 20:11 C2.4 N41W81 1069

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?

Page 5 AGU Fall 13-17, 2010

AR1066

AR1069

ID DATE & TIME (PEAK) FLARE LOCATION AR

1 2010/05/03 15:04 B1.4 S26E10 1066

2 2010/05/03 21:53 B1.0 S26E04 1066

3 2010/05/04 06:46 B1.9 N40W22 1069

4 2010/05/04 12:09 B1.3 N41W23 1069

5 2010/05/04 12:44 B1.7 N40W24 1069

6 2010/05/04 14:20 B2.4 N40W22 1069

7 2010/05/04 16:29 C3.6 N41W23 1069

8 2010/05/04 19:19 B1.1 N43W31 1069

9 2010/05/05 01:11 B1.6 N41W27 1069

10 2010/05/05 07:20 C2.3 N41W31 1069

11 2010/05/05 08:39 B2.4 N44W32 1069

12 2010/05/05 11:52 C8.8 N41W34 1069

13 2010/05/05 17:19 M1.2 N42W36 1069

14 2010/05/05 18:43 B7.3 N41W36 1069

15 2010/05/05 21:59 B1.7 N47W43 1069

16 2010/05/07 00:34 B1.1 N40W52 1069

17 2010/05/07 07:42 C2.0 N40W54 1069

18 2010/05/07 22:56 B4.6 N41W62 1069

19 2010/05/08 01:04 B2.6 N40W62 1069

20 2010/05/08 03:23 B4.3 N41W62 1069

21 2010/05/08 04:59 C9.3 N40W66 1069

22 2010/05/08 08:52 B2.1 N40W69 1069

23 2010/05/08 09:20 B2.1 N41W74 1069

24 2010/05/08 10:19 B3.8 N42W70 1069

25 2010/05/08 11:50 C1.8 N41W70 1069

26 2010/05/08 18:55 B7.2 N41W77 1069

27 2010/05/08 20:11 C2.4 N41W81 1069

Page 6 AGU 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.

Page 7 AGU 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.

Page 8 AGU Fall 13-17, 2010

Comparison of AR11066 and AR11069

P1 P1

N1

P1

NP

N2 P3P2

N1N1

P

P2N2

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.

Page 9 AGU Fall 13-17, 2010

Another Emerging Active Region-- AR11072 (southern hemisphere)

NN

PP

N

P

Another emerging active region, AR11072. Only a simple bipole field emerged in this region. No C-class and above flares occurred.

Page 10 AGU 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.

NN

PP

P

Page 11 AGU Fall 13-17, 2010

Another Emerging Active Region—Ar11082(northern hemisphere)

NN

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

Page 12 AGU 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.