Advisors

Birch, Aaron
Aaron Birch
Scientist
Phone: +49 551 384 979-379
Schunker, Hannah
Hannah Schunker
Phone: +49 551 384 979-440
Links: Homepage
Gizon, Laurent
Laurent Gizon
Director
Phone: +49 551 384 979-439
+49 551 384 979-299
+ 49 551 384 979-255
Links: Homepage

Open PhD Project

Flows associated with emerging solar active regions

Characterising flows associated with emerging active regions using SDO/HMI observations

Magnetic active regions on the Sun (including sunspots) are thought to have their origin in magnetic flux tubes that rise to the solar surface from deep in the convection zone.   Helioseismology promises to be able to detect the subsurface flows that are expected to be associated with these flux tubes beneath the solar surface.   In addition, helioseismology can measure the flows associated with active regions during their emergence through the solar surface, evolution, and decay.

This project will use helioseismology to carry out both statistical studies and case studies of emerging regions using SDO observations, in order to identify, describe, and interpret the phases of the emergence and evolution processes.   This work will have important implications for theories of the origin of active regions and the solar cycle by either detecting, or placing strong upper limits on, the subsurface flow fields associated with emerging active regions.  In addition, the near-surface flows fields measured in this work will provide important inputs to dynamo models of the solar cycle.

<span>East-West flows (colors) from a numerical model of a rising magnetic flux concentration at three days before emergence. The approximate paths of acoustic waves are shown in the black curves.  The acoustic waves are generated at the solar surface, and are refracted upwards as the sound speed increases with depth into the Sun.  The speed at which the waves propagate depends on the flows in the solar interior and as a result wave travel times can be used to measure flows in the interior of the Sun.  </span>
East-West flows (colors) from a numerical model of a rising magnetic flux concentration at three days before emergence. The approximate paths of acoustic waves are shown in the black curves.  The acoustic waves are generated at the solar surface, and are refracted upwards as the sound speed increases with depth into the Sun.  The speed at which the waves propagate depends on the flows in the solar interior and as a result wave travel times can be used to measure flows in the interior of the Sun.   [less]
 
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