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Time-distance analysis of the emerging Active Region NOAA 10790

Zharkov, S; Thompson, MJ; (2008) Time-distance analysis of the emerging Active Region NOAA 10790. In: SOLAR PHYSICS. (pp. 369 - 380). SPRINGER

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We investigate the emergence of Active Region NOAA 10790 by means of time-distance helioseismology. Shallow regions of increased sound speed at the location of increased magnetic activity are observed, with regions becoming deeper at the locations of sunspot pores. We also see a long-lasting region of decreased sound speed located underneath the region of the flux emergence, possibly relating to a temperature perturbation due to magnetic quenching of eddy diffusivity, or to a dense flux tube. We detect and track an object in the subsurface layers of the Sun characterised by increased sound speed which could be related to emerging magnetic-flux and thus obtain a provisional estimate of the speed of emergence of around 1 km s(-1).

Type:Proceedings paper
Title:Time-distance analysis of the emerging Active Region NOAA 10790
Event:International Conference on Helioseismology, Asteroseismology and MHD Connections (HELAS II)
Location:Gottingen, GERMANY
Dates:2007-08-20 - 2008-08-24
Keywords:sun : Active Region emergence, sun : time-distance helioseismology, FLUX TRANSPORT, MAGNETIC-FLUX, HELIOSEISMOLOGY, INVERSION, DYNAMO, ZONE
UCL classification:UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Space and Climate Physics

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