Volume : IV, Issue : VIII, August - 2014

The Evolution of Global Twist in Active Region NOAA 10930

Yogita Suthar, S. N. A. Jaaffrey, Mukesh Shrimali

Abstract :

Twist parameter αg is measured in the present study with its variability and sign along the magnetic field line of force observed in an active region NOAA AR 10930 by Hinode (Solar Optical Telescope/Spectropolarimeter). The data has been caliated from level 0 to level 1 by using the standard “SP_PREP”and taking as1σ for noise level. We estimated accurate value of αg for North polarity from – 4 x 10–8 to 1 x 10–8 m–1 with 60% argumentation with regards to South polarity. Flare occurred on Dec 13, 2006 after which both αg and area of active region started decreasing. At South polarity, αg recovered the initial value very close to zero whereas north polarity did not but persisted with residual of –9 x 10–8 m–1 at the end of flare. Inverse value of αg is referred to number of twist in active area at given height on the surface of photosphere of the Sun such that the low values of αg promise for substantial decrease of activities and large values guarantee for big flare eruption in active region of sunspot.

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Article: Download PDF   DOI : 10.36106/ijar  

Cite This Article:

Yogita Suthar, S.N.A. Jaaffrey, Mukesh Shrimali The Evolution of Global Twist in Active Region Noaa 10930 Indian Journal of Applied Research, Vol.4, Issue.8 August 2014

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