correlation length of energy at the base of coronal holes

Correlation Length of Energy at the Base of Coronal Holes

Valentina Abramenko 1

Gary Zank 2

Alexander Dosch 2

Vasyl Yurchyshyn 1

1 - Big Bear solar Observatory of NJIT, CA

2 – CSPAR, Univ. of Alabama in Nuntsville, AL

Photospheric motions are immediately transferred into the chromosphere and corona

Magnetic and velocity fluctuations were analyzed in the photosphere inside two coronal holes

u2

ux , uy

Correlation Function of u2 :

Correlation function allows to estimate a characteristic length λof energy containing structures, which defines directly the heating rate:

Matthaeus et al. 1999:

Zank et al. 2012:

Correlation Function:

Correlation function allows to estimate a characteristic length by different ways:

1.To determine the Batchelor integral scale:

2. From an exponential fit to calculate the correlation length ζ

3. To calculate the e-folding scale L of the correlation function.

Calculated Correlation Functions of u2 structures

Parallel and Normal Correlation Functions of ux and uy velocity components

16 Mm

HMI (0.5”) 2011/08/12

SOT/SP (0.16”) 2007/03/10NST (0.098”) 2012/06/02

36 Mm120 Mm

Magnetic Field in Coronal Holes

Correlation Functions from magnetic field fluctuations

Magnetic and Kinetic Power Specra

at the Base of Coronal HolesValentina Abramenko

Big Bear solar Observatory of NJIT, CA

Kinetic and Magnetic Energy SpectraObserved Velocity Spectra

Kinetic and Magnetic Energy SpectraObserved Magnetic Spectra

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XXV IUGG/IAGA, Melbourne, Australia

k-1/3