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تسجيل مستخدم جديدOn Making Magnetic-Flux-Rope $Omega$ Loops for Solar Bipolar Magnetic Regions of All Sizes by Convection Cells
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We propose that the flux-rope $Omega$ loop that emerges to become any bipolar magnetic region (BMR) is made by a convection cell of the $Omega$-loops size from initially-horizontal magnetic field ingested through the cells bottom. This idea is based on (1) observed characteristics of BMRs of all spans ($sim$ 1000 km to $sim$ 200,000 km), (2) a well-known simulation of the production of a BMR by a supergranule-size convection cell from horizontal field placed at cell bottom, and (3) a well-known convection-zone simulation. From the observations and simulations, we (1) infer that the strength of the field ingested by the biggest convection cells (giant cells) to make the biggest BMR $Omega$ loops is $sim$ 10$^3$ G, (2) plausibly explain why the span and flux of the biggest observed BMRs are $sim$ 200,000 km and $sim$ 10$^{22}$ Mx, (3) suggest how giant cells might also make failed-BMR $Omega$ loops that populate the upper convection zone with horizontal field, from which smaller convection cells make BMR $Omega$ loops of their size, (4) suggest why sunspots observed in a sunspot cycles declining phase tend to violate the hemispheric helicity rule, and (5) support a previously-proposed amended Babcock scenario for the sunspot cycles dynamo process. Because the proposed convection-based heuristic model for making a sunspot-BMR $Omega$ loop avoids having $sim$ 10$^5$ G field in the initial flux rope at the bottom of the convection zone, it is an appealing alternative to the present magnetic-buoyancy-based standard scenario and warrants testing by high-enough-resolution giant-cell magnetoconvection simulations.
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