Recent Improvements of Kinematic Models of the Solar Magnetic Cycle
Abstract
One of the best tools we have for understanding the origin of solar magnetic variability are kinematic dynamo models. During the last decade, this type of models has seen a continuous evolution and has become increasingly successful at reproducing solar cycle characteristics. Unfortunately, most of ingredients that make up a kinematic dynamo model remain poorly constrained allowing one to obtain solar-like solutions by 'tuning' the input parameters' leading to controversy regarding which parameter set is more appropriate. In this poster we will revisit two of those ingredients and show how to constrain them better by using observational data and theoretical considerations.
For the turbulent magnetic diffusivity - an ingredient which attempts to capture the effect of convective turbulence on the large scale magnetic field - we show that combining mixing-length theory estimates with magnetic quenching allows us to obtain viable magnetic cycles (otherwise impossible) and that the commonly used diffusivity profiles can be understood as a spatiotemporal average of this process. For the poloidal source - the ingredient which closes the cycle by regenerating the poloidal magnetic field - we introduce a more realistic way of modeling active region emergence and decay and find that this resolves existing discrepancies between kinematic dynamo models and surface flux transport simulations. This formulation has made possible to study the physical mechanisms leading to the extended minimum of cycle 23 and paves the way for future coupling between kinematic dynamos and models of the solar corona. This work is funded by NASA Living With a Star Grant NNX08AW53G to Montana State University/Harvard-Smithsonian Center for Astrophysics and the Government of India's Ramanujan Fellowship.- Publication:
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Solar Heliospheric and INterplanetary Environment (SHINE 2011)
- Pub Date:
- July 2011
- Bibcode:
- 2011shin.confE...3M