R.T. James McAteer New Mexico State University. James McAteer New Mexico State University 1 ISSI meeting 2 Sept, 2013 ISSI meeting Sept, 2013 Maybe SOC? Scale free, maybe SOC Fractals,

The Search for Units: A Gradient Distribution route to Multifractality in

Solar Magnetic Fields

R.T. James McAteerNew Mexico State University

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ISSI meetingSept, 20132


Maybe SOC?Scale free, maybe SOC

Fractals, maybe SOC

Units, in SOC

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The Why and The How

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Connection to SOCallows for energy build up over timescales much longer than energy release

allows for a system to approach SOC

requires a threshold in ‘energy’ which must be followed by a release of energy

dictates energy output sizescales much less than spatial scale of system. 5


Scale free, maybe SOC?

Abramenko 2002, 2005, 2006Hewett, McAeer et al., 2008

E(k) ~ k-a

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Scale free, maybe SOC

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Fractals, maybe SOCMcAteer et al., 2005

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2700 days9300 images

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Units, in SOC

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gradients, gradients, gradients,...

Sammis et al, ApJ, 2000, 540, 587Schrijver, ApJ, 2007, 655, L117Falconer et al., ApJ, 2008, 689, 1433Al-Ghraibai, Boucheron, McAteer, ApJ, 201316


gradients, gradients, gradients

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dB/dx, dB/dy

Jz

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Size of gradientSize of gradient at each scale

0 0.5 1.0

#or

D(h)

h

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Wavelet Transform Modulus Maxima

(1) Take a *multiscale* gradient(2) At the smallest spatial, detect a strong gradient.(3) Track this gradient up through each size scale. (4) Calculate partition function

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The quiet Sun

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Wavelet Transform Modulus Maxima

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New flux arises near to ‘strong’ gradientsNew gradients arise near ‘strong’ gradients

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Maybe SOC?


Fractals, maybe SOC

Units, in SOC

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ProblemsWe’re measuring the wrong part of the active region?

Energy build up in transverse component of magnetic field.

Magnetic field in corona is where the flare occurs.

We only measure the driver of the build up of energy.

What is the appropriate time scale?Sun doesn’t care what is happening on 24 hour timescale.

Is there a strong solar cycle dependence?

Flaring is non-Poisson - events are not independent.

What is a big flare?What is the total energy in an event? How is this distributed between radiation, particle, coronal mass ejection, etc..?

Careful not to succumb to big-flare syndrome

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Looking forwardDetection of energy release mechanism.

how much energy is available?

how much energy is released?

how much energy is needed to maintain a stable active region?

Predictions over appropriate timescales.

How do we combine the maximum predictive timescale of each measure and flare size?

ConclusionsThe multifractal spectrum is a number distribution of gradient persistence to high spatial scales

higher h, higher D, more energy build up

pointer to further flux emergence and gradient build up

this may the connection to resulting flares.

Is there a maximum predictive timescale of each measure?

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Accuracy depends: predict X class / fast CME (HSS 0.7) 12 hourspredict C class (HSS 0.65) over 72 hours.

Bloomfield et al, ApJ, 2012Also Poster Session 6.1

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Questions

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What about some Units?Multifractal spectrum is directly related to the distribution of gradients

Magnetic Gradients(G / Mm)


StrengthStrengthMagnetic Gradients(G / Mm)

Magnetic Gradients(G / Mm) 300 25

#5 D=1.2 D=1.0

#25 D=1.45 D=1.2





#4 D=1.3 D=1.0

#20 D=1.45 D=1.1





#2 D=1.4 D=1.0

#10 D=1.45 D=1.05

2 pixels

16 pixels4 pixels

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Where are the gradients? Abramenko, 2005, ApJ

Hewett, Gallagher, McAteer, et al., 2008, Solar Physics, 248, 311

Size Scaling index related to structure function

Ireland, Young, McAteer, et al., 2008, Solar Physics, 252, 121

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Outline

The promise of flare prediction

The premise of flare prediction

The problems of flare prediction


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“Big and Ugly’

Prediction requires understanding


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Outline



The problems of flare prediction


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Big and Ugly?

Global properties are useful

Local properties are key

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The premise of flare predictionAbramenko, ApJ, 2005Conlon, McAteer et al., ApJ, 2010

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What flare size?

What timescale?

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Paul Higgins 2009

Leka & Barnes ApJ, 2003Higgins et al, ASR, 2010

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Paul Higgins 2009

What flare size?

What timescale?

What parameters matter?

What is accurate flare prediction?

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Outline



The problems of flare predictionThe problems of flare prediction

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Conclusions

Progress is significant

solar cycle of synoptic data

Combination of local and global properties works at HSS score of 0.8

Looking forward to full disk vector data.

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R.T. James McAteer New Mexico State University. James McAteer New Mexico State University 1 ISSI meeting 2 Sept, 2013 ISSI meeting Sept, 2013 Maybe SOC? Scale free, maybe SOC Fractals,

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