Abstract Details
| Name: Sankalp Gilda Affiliation: Birla Institute of Technology and Science - Pilani Conference ID: ASI2015_884 Title : THEORETICAL ESTIMATES OF ACOUSTIC WAVE TRAVEL-TIME SIGNATURES DUE TO DEEP DOUBLE-CELL MERIDIONAL FLOWS IN THE SUN Authors and Co-Authors : Dr. S.P. Rajaguru Indian Institute of Astrophysics, Bangalore Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : In view of the recent claims about the existence of a second meridional cell, stacked radially below the first one, we have carried out theoretical calculations to get independent confirmation of the results. Specifically, we have referred to \emph{Zhao et al. (2013)}, where the authors have used two years of helioseismic data from HMI to analyze travel times of acoustic waves propagating through different depths in the solar interior, and concluded that a two-cell meridional circulation profile with a poleward flow below 0.82${R_\odot}$ would still give time differences comparable to those from other independent measurements, thus suggesting a rethinking of generation and transport of solar magnetic flux. For our work we have used stream functions similar to those used by \emph{Hazra, Karat et al. (2014)} to replicate Zhao's velocity profile, and the standard solar model by Christensen-Daalsgard to calculate travel time differences for this profile. We have used the standard ray approximation to the 3-D wave equation, and considered only the first bounces of acoustic waves at the upper turning points. Our theoretical results fail to replicate Zhao's travel time results; this leads us to conclude that the present research cannot conclusively establish the presence of a second meridional cell, and further research including analysis of longer-duration data is needed to settle the matter one way or the other. |