Speaker
Hannah Schunker
(Max Planck Institute for Solar System Research)
Description
Traditionally, the subsurface structure of sunspots has been
inferred using local helioseismic techniques treating the
sunspot as a weak perturbation to the waves, however, we
show that the surface of the sunspot has a strong effect on
the waves. Using 3D MHD simulations of the response of
seismic waves to sunspot models with various perturbations,
we find that subsurface sound-speed perturbations to a
sunspot model introduce smaller travel-time-shifts than
perturbations to the quiet-Sun. One way to avoid the strong
surface effect is to study sunspots before they emerge at
the surface.
In an effort to helioseismically detect and study sunspot regions before, during and after emergence, we have identified 105 emerging sunspot regions (and corresponding quiet-Sun control regions) observed by SDO/HMI between May 2010 to December 2012. The Doppler velocities were then analysed using helioseismic holography to obtain travel-time maps at the surface and at various depths below. This is the largest catalogue of emerging sunspot regions observed by SDO-HMI to-date, containing over 8TB of data, processed and stored in the German Data Centre for SDO housed at the MPS. Here we present the surface magnetic field properties and flow maps of the dataset.
In an effort to helioseismically detect and study sunspot regions before, during and after emergence, we have identified 105 emerging sunspot regions (and corresponding quiet-Sun control regions) observed by SDO/HMI between May 2010 to December 2012. The Doppler velocities were then analysed using helioseismic holography to obtain travel-time maps at the surface and at various depths below. This is the largest catalogue of emerging sunspot regions observed by SDO-HMI to-date, containing over 8TB of data, processed and stored in the German Data Centre for SDO housed at the MPS. Here we present the surface magnetic field properties and flow maps of the dataset.
Primary author
Hannah Schunker
(Max Planck Institute for Solar System Research)
