The 2nd Solar-C Science Definition Meeting
March 11-14, 2010@ISAS, Sagamihara, Japan	Space Weather Study- Flare Forecast Kanya Kusano
Solar Terrestrial Environment Laboratory
Nagoya University
1

The Process of Space Weather	source	propagation	

impact	The Sun	Interplanetary	Geo-space	

Flare, CME	ICME, Shocks	

Storm, Sub-storm, etc	earthquake	tsunami	2

Why should we forecast flares ?	
As the Space Weather Forecast
 To evaluate the level of scientificunderstandingWhen	How	10.9.30

Two types of onset process	
Triggered phenomena	

Critical phenomena	

Trigger	meta-stable state	

unstable state	

Sawtoothin tokamak	Triggered or Critical	
Triggered phenomena	

Moor et al. 2001	

tether cutting model
flux cancellation model	

Critical phenomena	

Fun & Gibson 2007	

ideal kink modelcatastrophe model	

Method 1: Machine-learning	

Automated Solar Activity Prediction:
Space Weather Prediction Center Colak & Qahwaji 2009, HN Wang et al. 2008Colak & Qahwaji 2009	
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Skill Score	

Skill Score of SWPC for X flare
1day
2day
3day
year (events)
0.112-0.147-0.171
2006 (4)
0.242
0.147
0.127
2005 (13)0.052-0.001-0.044
2004 (9)
0.200
0.093
0.076
2003 (17)-0.037-0.050-0.033
2002 (12)-0.061-0.034-0.006
2001 (18)	
10.9.30

Flares and Subsurface vorticity	

Komm & Hill 2009 JGR	10.9.30

Method 2: Correlative Analysis	To find magnetic quantity, which is mostcorrelated to the onset of flares.
Leka & Barnes 2007, Yamamoto & Sakurai 200910.9.30

10.9.30

Evaluating the performance of solar flare forecasting
methods, Barnes and Leka 2008	

(M&X class within 1d)	Eventnumber	no flare	flare	

R: unsigned flux
over the highgradient polarityseparation lines
Schrijver 2007	Total excess energy
Leka & Barnes 2003	

Effective connectedmagnetic field
Georgoulis & Rust 2007	

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Method 3: 3D Model	

Static Model

NLFFF extrapolation
SOT	Vector
Magnetogram

MDI Synoptic Map

Nonlinear ForceFree Field

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Chromospheric model is needed	

Photospheric data is NOT consistent with
NLFF equation.	
B	
corona	J||	chromosphere	Jz	photosphere	“pre-conditioning” has to be applied to photospheric data.	
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AR 10930 (2006 Dec. 13)	NLFF model	

Observation	
sunspot	
SOT	flare ribbons	

XRT	Potential Field	2006_12_11
17:00 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

533h prior to
the flare	
2006_12_11
17:00 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

521h prior to
the flare	
2006_12_1203:50 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

58h prior to
the flare	
2006_12_12
17:40 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

55h prior to
the flare
2006_12_12
20:30 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

55h afterthe flare	
2006_12_13
07:00 UT	
Total Magnetic Energy
Magnetic Free Energy(J)	
1.00E+26
9.00E+25
8.00E+25
7.00E+25
6.00E+25

flare	

5.00E+25
4.00E+25
3.00E+25
2.00E+25
1.00E+25
0.00E+00
123410.9.30

5

pre-flare brightening and magnetic field	

2006.12.13 01:42:37

Numerical experiment of the flare	
mag. energy	
forcing	liberatedenergy	

without forcing	time	
Small forcing on the foot-point is able to trigger energy
liberation, which corresponds to flare.	

velocity Vz>0, Vz<0	X-ray Ejections & X-ray Wavedata 8h prior to 	data 21h prior to 	courtesy of Asai-san	Extension to CME model	
Solar wind model CME model ICME model Magnetosphere model

Shiota et al 2009	

Kataoka et al 2009	
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Summary	
The methods to forecast flares is now being developed interms of several algorithms.
 The data-driven MHD model using Hinode’s vector
magnetogram is very promising to reproduce flare activity
as well as to evaluate the “vulnerability” of active region.
However, it is still premature to predict when flare occurs.
 Solar flare might be a triggered process rather than a criticalprocess. So, we probably need higher-cadence data to findthe real trigger.
 Solar-C/B could be a powerful tool for forecasting flare.
However, many experiments to do using Hinode’s data is
not completed yet.
10.9.30

Inversion of the Induction eq.	
ＬＣＴ

Kusano et al. 2002が必要
Fisher et al.2010	

Welsch et al. 2007	

山本さんから提供 2009 Hinode-3	10.9.30