When
3:30 p.m., Sept. 13, 2011
Where
Kuiper Space Sciences 308
Dr. Matthias Rempel
High Altitude Observatory/
University Corporation for Atmospheric Research
"Numerical Simulations of Sunspots: From the Scale of Fine Structure to the Scale of Active Regions"
Abstract:
Over that past five years magneto-convective sunspot models have seen a dramatic improvement to the point at which simulations of entire sunspots with sufficient detail for resolving sunspot fine structure are possible. After a brief review of recent developments I will focus on three different classes of numerical sunspot models. 1.) Sunspot simulations at the highest currently affordable resolution that focus on details of sunspot fine structure: I will highlight the magneto-convective processes that are responsible for the energy transport, filamentation and driving of the Evershed flow in sunspot penumbrae. 2.) Sunspot models at lower resolution that can be evolved for time scales of several days in computational domains with horizontal extents beyond 50 Mm: These models start to address the subsurface field and flow structure of sunspots and their surroundings as well as processes related to sunspot decay. In addition, these simulations are used as a testbed for helioseismic inversion methods. 3.) Sunspot models on the scale of active regions: These models capture the last stages of the flux emergence and sunspot formation process in the upper most 10 to 20 Mm of the convection zone. After the initial flux dispersal due to the strong expansion of emerging flux a re-amplification of flux into ~3 kG sunspots are found as a robust result.
High Altitude Observatory/
University Corporation for Atmospheric Research
"Numerical Simulations of Sunspots: From the Scale of Fine Structure to the Scale of Active Regions"
Abstract:
Over that past five years magneto-convective sunspot models have seen a dramatic improvement to the point at which simulations of entire sunspots with sufficient detail for resolving sunspot fine structure are possible. After a brief review of recent developments I will focus on three different classes of numerical sunspot models. 1.) Sunspot simulations at the highest currently affordable resolution that focus on details of sunspot fine structure: I will highlight the magneto-convective processes that are responsible for the energy transport, filamentation and driving of the Evershed flow in sunspot penumbrae. 2.) Sunspot models at lower resolution that can be evolved for time scales of several days in computational domains with horizontal extents beyond 50 Mm: These models start to address the subsurface field and flow structure of sunspots and their surroundings as well as processes related to sunspot decay. In addition, these simulations are used as a testbed for helioseismic inversion methods. 3.) Sunspot models on the scale of active regions: These models capture the last stages of the flux emergence and sunspot formation process in the upper most 10 to 20 Mm of the convection zone. After the initial flux dispersal due to the strong expansion of emerging flux a re-amplification of flux into ~3 kG sunspots are found as a robust result.
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