Takayoshi SANO, Osaka University, JAPAN
In Masada & Sano (2016, ApJL), we reported the successful simulation of the spontaneous formation of surface magnetic structures from large-scale dynamo in strongly-stratified convection. In this talk, we will present our recent studies on the Rossby number (Ro) dependence of the large-scale dynamo in the strongly-stratified convection. From our parametric survey, we find that the critical Rossby number that separates the success and failure of the large-scale dynamo is in the range 0.02 < Ro < 0.04. It is also found that the Ro-dependence of the large-scale dynamo can be reproduced by the mean-field α^2-type dynamo model constructed with using turbulent velocity profiles extracted from the DNS (see also, Masada & Sano 2014, ApJL). The physics of the Rossby number dependence of the convective dynamo and its application to the solar/stellar dynamo modeling are finally discussed with focusing on the rotational modulation of the profiles of the turbulent transport coefficients.
Mode of presentation: oral (Need to be confirmed by the SOC)