Abstract Details
| Name: Gopal Hazra Affiliation: Indian Institute of Science Conference ID: ASI2016_639 Title : A Three-Dimensional Babcock-Leighton Solar Dynamo Model with Non-Axisymmetric Subsurface Flow Authors and Co-Authors : Mark Miesch, High Altitude Observatory,Boulder Abstract Type : Poster Abstract Category : Sun and the Solar System Abstract : The study of photospheric magnetic field evolution is very important because it is the only observable part of the Babcock-Leighton dynamo models and it sets the boundary condition for the coronal and heliospheric magnetic fields. Observationally it is evident that the solar photospheric magnetic fields is mostly transported by the large scale and small scale surface flows i.e, Differential Rotation, Meridional Circulation and Convective flows ( granular and supergranular flows ). Presently most of the Babcock-Leighton Models use only the axisymmetric flows of sun. We are now incorporating the non-axisymmetric convective flows in our model also which are based on the observation of doppler measurement of the solar photosphere. From observation we have only the velocity measurement of the photosphere which is mainly horizontal flows on the surface but our model is a 3D model so we have extrapolated the horizontal surface flows radially below the photosphere inside the convection zone assuming that the mass flux is divergenceless. Since we have incorporated large scale and small scale velocity field simultaneously, the evolution of radial magnetic field on the surface of the sun more closely matches the observation. Convective velocity fields are mostly responsible for diffusive transport of flux on the solar surface also, so at last we run some simulations varying the diffusivity of the surface so that we can have some estimate of the diffusion co-efficient which reproduce the results including the convective flow fields. |