Simulating global distribution of surface active regions from their deep-origins
Abstract
Spot-producing magnetic fields are most likely generated by a dynamo in a layer at the base of the convection zone. These dynamo-generated fields contain information about the amplitude and duration of a solar cycle. But where and when does this dynamo-generated flux emerge from the deep layer to the surface, in the form of active regions? What size and strength will these active regions have? We demonstrate that the dynamo-genrated spot-producing toroidal magnetic fields undergo nonlinear dynamics in the deep shear-layer (tachocline), which create "imprints" of locations at their original depth. From there they buoyantly erupt to the surface, thus determining their surface latitude-longitude location, as well as the timing of their eruption and their strength. We show that in a data-driven simulation the model can correctly simulate the global distribution of active regions for a few months. In order to generate a time sequence of active regions up to a year or more ahead, we assimilate surface magnetic patterns into the simulation. This provides the potential to predict the occurrence of a quasi-annual enhanced space weather "season" several months ahead. This would lead to space weather forecasts on intermediate time scales (few-weeks-to-few-years), filling in the gap between existing very short (hours-to-days) and very long (decadal) time-scale forecasts.
- Publication:
-
43rd COSPAR Scientific Assembly. Held 28 January - 4 February
- Pub Date:
- January 2021
- Bibcode:
- 2021cosp...43E1727D