Conveners
Flux emergence: observational and theoretical results
- There are no conveners in this block
Flux emergence: observational and theoretical results
- Rainer Arlt (Potsdam)
Flux emergence: observational and theoretical results
- Karel Schrijver (Lockheed)
Flux emergence: observational and theoretical results
- Alexander Kosovichev (Big Beer)
Andres Munoz-Jaramillo
(Montana State University)
3/9/15, 2:30 PM
Besides the detailed observation and simulations of
individual sunspots, the statistical analysis of sunspot
populations can provide crucial hints on the mechanisms that
shape magnetism in the photosphere. In this presentation we
will discuss the results of an ongoing statistical analysis
of 11 different sunspot, sunspot group, and bipolar magnetic
region databases. The focus of our work...
Aimee Norton
(Stanford University)
3/9/15, 3:10 PM
We report on the formation and decay of active regions as
observed with HMI vector B and Ic data. Observed quantities
such as flux emergence rates and maximum footpoint
separations can be used to test the accuracy of numerical
simulations of sunspot formation. We calculated the
emergence and decay rates with and without intensity
contours, i.e., we differentiate between flux emergence...
Irina Kitiashvili
(NASA Ames Research Center)
3/9/15, 4:10 PM
The surface of the Sun is covered by continuously emerging
and evolving ``magnetic carpet''. I will present results of
realistic numerical simulations showing that the magnetic
carpet can result from the turbulent dynamo operating in a
shallow subsurface layer. The simulation results reveal
details of the dynamo mechanism and formation of small-scale
magnetic structures.
András Ludmány
(MTA Debrecen Heliophysical Observatory)
3/9/15, 4:50 PM
A refined form of the well known Joy's law has been
formulated by using the new Debrecen tilt angle data. It has
been found that the latitudinal distribution of the tilt
angles is not merely a monotonously increasing function, but
it has a plateau between the latitudes of about 15-25
degrees, where the toroidal field is the strongest. This may
imply an impact of the azimuthal magnetic...
Hannah Schunker
(Max Planck Institute for Solar System Research)
3/10/15, 9:00 AM
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...
Nazaret Bello Gonzalez
(Kiepenheuer-Institut fuer Sonnenphysik)
3/10/15, 9:40 AM
The evolution of NOAA11024 from a protospot into a
fully-developed sunspot was followed in detail from
high-resolution observations. The affluence of continuously
emerging magnetic flux assembling the developing spot, the
action of twist and shear motions, the presence of a broad
magnetic canopy beyond the spot intensity boundaries, the
role of light bridges as natural path to gather the...
Chia-Hsien Lin
(National Central University)
3/10/15, 10:00 AM
Early theoretical studies of flux emergence showed that
solar magnetic fields are brought up to the surface by
magnetic buoyancy. In recent years, sophisticated numerical
models have been developed to include other effects, such as
solar rotation, convection, twisting and geometry of the
magnetic flux tube. The objective of this work is to examine
how significant these effects are on the...
Bob Stein
(Michigan State University)
3/10/15, 10:50 AM
Simulation results will be shown for two cases: weak,
non-buoyant and strong, buoyant uniform, untwisted,
horizontal magnetic fields advected into the computational
domain by inflows at 20 Mm depth. Convection both shreds
the magnetic field into many thin fibrils as well as keeps
the larger-scale structure confined within the inflow
supergranule cell. Convective upflows and downflows...
