Bidya Binay Karak

NameBidya Binay Karak
AffiliationIndian Institute of Technology (BHU), Varanasi
TitleNonlinearities for the saturation of the magnetic field in the Sun
AuthorsBidya Binay Karak
AbstractThe magnetic field of the Sun increases and decreases in time with a polarity reversal every 11 years. The most interesting aspect here is that the amplitude of the field does not grow all the time, although there is a considerable variation in time. We try to explain this problem under the Babcock-Leighton dynamo framework which appears to be the most successful model for the solar cycle at present. However, most of these models are kinematic, and the saturation of the magnetic field is not well-constrained. We demonstrate a recently proposed mechanism for this under the Babcock–Leighton dynamo framework. This mechanism is based on the observational fact that the stronger solar cycles produce bipolar magnetic regions (BMRs) at higher latitudes and thus have higher mean latitudes than the weaker ones. We capture this effect in our three-dimensional Babcock–Leighton solar dynamo model and show that when the toroidal magnetic field tries to grow, it produces BMRs at higher latitudes. The BMRs at higher latitudes generate a less poloidal field, which consequently limits the overall growth of the magnetic field in our model. Thus, our study suggests that the latitudinal variation of BMRs is a potential mechanism for limiting the magnetic field growth in the Sun.