Joint Instability of Latitudinal Differential Rotation and Concentrated Toroidal Fields below the Solar Convection Zone. II. Instability of Narrow Bands at All Latitudes

摘要: Assuming that concentrated toroidal field bands occur in the solar tachocline at different latitudes as cycle progresses, we examine joint instability of latitudinal differential rotation and coexisting narrow placed a wide range latitudes. Following basic formalism developed by Gilman & Fox employing numerical technique Dikpati Gilman, show exists for almost all phases cycle, i.e., positions strengths between 500 G 200 kG. Modes with longitudinal wavenumber m = 1 up to 7, depending on parameter values, are unstable both kinds symmetries. Mid-latitude most unstable; disappears if band is very high or low High-latitude highly unstable, e-folding growth times few months, even when strength (about hundred gauss); low-latitude longer (≥1 yr), but (104-2 × 105 G). We argue that, because instability, high-latitude would undergo turbulent mixing direction timescale short compared their build-up time from shearing poloidal rotation, thus they may not be buoyant enough appear active regions surface, can build simultaneously this eventually manifest regions. Instability modes ≥ could help determine longitude distribution regions; nonlinear changes due contribute decay.