DR. BIDYA BINAY KARAK

It is believed that the magnetohydrodynamics processes are responsible for producing the stellar magnetic field and associated phenomena. However, due to extreme conditions in the stellar convection zones, the direct numerical simulation of magnetohydrodynamics is challenging. The speaker shall discuss recent efforts in performing the rotating global-convection simulation in spherical geometry of the stellar convection zones. He shall show that under certain parameter regimes, simulations are successful in reproducing the basic characteristics of the stellar cycles. Features and the origin of the differential rotation produced in these simulations will also be discussed. Finally, he shall describe a Babcock-Leighton dynamo model in which bipolar sunspots are deposited into this model based on solar observations. Using this model, he shall demonstrate that the randomness in the tilt angle of the bipolar sunspot is a cause of the variation in the sunspot cycle.