Spatio-Temporal Dynamics of Magnetic Fields and Flaring Productivity of Active Regions

Spatio-Temporal Dynamics ofMagnetic Fields

and Flaring Productivity of Active Regions

Valentina I. AbramenkoBig Bear Solar Observatory of NJIT

Email: [email protected]://www.bbso.njit.edu/~avi/

mailto:[email protected]

mailto:[email protected]

Introduction

The 2005 Joint Assembly / AGU,SEG, NABS and SPD/AAS, May 23-27, 2005, New Orleans, LA, USA

Introduction

Essential properties of the photospheric plasma:

Magnetized plasma in a turbulent state (Parker 1979),very intermittent (or, in other words, multifractal) medium (Lawrence et al. 1993, Abramenko et al. 2002),

where the magnetic helicity may have an inverse cascade (Biskamp 1993)

IntroductionSituation in the photosphere – flaring in the corona:

Magnetic helicity transport in the photosphere (Rust & LaBonte 2003; Georgoulis – present meeting; Chae2001; Romano 2005 ).

Statistical properties of electric currents, current helecity, magnetic flux, etc., derived from vector-magnetograms (Leka & Barnes 2004).

Fractal dimensions of the photospheric magnetic fields (Tarbell et al. 1990; Balke et al. 1993; Meunier 1999;

McAteer, Gallagher & Ireland 2005).

IntroductionSituation in the photosphere – flaring in the corona:

we propose to analyze

1. Distribution functions of the magnetic flux in elements of the magnetic field in active regions

(Abramenko & Longcope, ApJ, 2005)

2. Multifractality (intermittency) of the photospheric magnetic fields – poster SP41B-04 (Abramenko, Yurchyshyn, Wang, Goode, ApJ 577, 2002).

3. Turbulence state of the photospheric magnetic field as derived from magnetic power spectrum – present talk.

Observational Data:SoHO/MDI high resolution magnetograms

http://www.bbso.njit.edu/~avi/PowerSp.pdf

Soft X-ray Flare Index

For example, during 13 days an active region launched flares:

X5.2 , M1.2 , C6.0

A=(520 + 12 + 6.0) / 13 = 41.4 (in units 10 W m )-6 -2


Magnetic Power SpectrumFlare-quiet active region 0061 (A=2.6) Flaring active region 9077 (A=120)


Magnetic Power Spectrum:time-variations of the power index

Flare-quiet active region 0061:

Flaring active region 9077:


Magnetic Power Spectrum:emerging active region


Soft X-ray Flare Indexversus Magnetic power index


Magnetic Power Spectrum:calculations

kx

yk


Table 2: Emerging Active Regions


Table 1: Active Regions


Emerging of a Flare-quiet Active Region NOAA 9851


Emergence of a Flaring Active Region NOAA 0365


Spatio-Temporal Dynamics of Magnetic Fields and Flaring Productivity of Active Regions

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