Abstracts Details


First Name * : Bibhuti Kumar
Last Name * : Jha
Affiliation * : Indian Institute of Astrophysics
Abstract Type * : Poster
Title * : Magnetic field dependency of bipolar magnetic region tilt angle: A study using MDI and HMI data sets
Author(s) * : Bibhuti Kumar Jha, Bidya Binay Karak , Sudip Mandal and Dipanker Banerjee
Abstract Session * : Thermal and magnetic coupling through the atmosphere
Abstract * : Centres of two bi-poles of a sunspot are separated by a latitude, i.e., sunspots are tilted with respect to the equator. Because of this tilt, when sunspots decay and disperse their fluxes, they produce a net poloidal magnetic flux near the pole, this is the popular Babcock-Leighton process. In this work, we explore the magnetic field dependence of the sunspot tilts, for that, we utilize the MDI onboard SOHO magnetogram images from May 1996 to April 2011 and HMI onboard SDO magnetogram from May 2010 to August 2018. We have followed the procedure as discussed in Stenflow et al(2012) to identify the bipolar regions in the line of sight full-disk magnetogram. We find that sunspot tilts have some magnetic field dependence. Our preliminary results show that the tilt decreases with the increase of the peak field strength of sunspots. This non-linearly decreasing trend of sunspot tilt with the increase of field strength can, therefore, act as a potential source of the quenching in the poloidal field generation process to stabilize the dynamo growth in the Babcock-Leighton type dynamo models.