Abstract Details

Name: Krishnendu Mandal
Affiliation: Tata Institute of Fundamental Research
Conference ID: ASI2017_566
Title : Computation of 3d spherical kernel for the understanding of meridional circulation
Authors and Co-Authors : Samrat Halder, Jishnu Bhattacharya, Shravan Hanasoge
Abstract Type : Oral
Abstract Category : Sun and the Solar System
Abstract : Understanding the Meridional circulation in the Sun is utmost importance for the modelling of solar dynamo process. Though meridional circulation was detected on the solar surface, still there are following few aspects of meridional circulation that are not well understood 1) whether a single flow spans the whole depth of convection zone or there are multiple cells stacked on top of each other, 2)the depth at which equatorward flow returns i.e whether meridional cir- culation is shallow or deep, 3)uncertainty about the speed of the equatorward return flow. To understand all the above mentioned features, we need to do inversion of the solar oscillation data (a method in time distance helioseismology). Compu- tations of the kernels is important for doing the inversion. Till now, people have used ray kernels for the inversion. Results obtained by this method is doubtfull because ray approximations is not a good approximation for solar 5 min. oscilla- tion. Understanding the limitation of the ray kernel, we have computed kernels using wave theory. We have used first order Born approximation to compute the kernels and tested it with the analytical value. Our next goal is to use this kernel for the inversion of the solar oscillations data. In this meeting, I shall present about our work in which we have computed the spherical 3d kernels and how it will help to infer about the features of the meridional circulation.