Login

Sunspot Formation: Theory, Simulations and Observations

9–13 Mar 2015
Albanova, Stockholm
Europe/Stockholm timezone

Session

Flux emergence: observational and theoretical results

Session 3
9 Mar 2015, 14:30
Oskar Klein Auditorium (Albanova, Stockholm)

Oskar Klein Auditorium

Albanova, Stockholm

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)

Presentation materials

There are no materials yet.

  1. 318. One Model Doesn't Fit All: Recent Results of a Detailed Analysis of Sunspot Demographics
    Andres Munoz-Jaramillo (Montana State University)
    09/03/2015, 14:30
    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...
    Go to contribution page
  2. 282. Emergence and Decay of Sunspots Groups Observed with HMI
    Aimee Norton (Stanford University)
    09/03/2015, 15:10
    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...
    Go to contribution page
  3. 271. Small-scale emerging flux and local dynamo action
    Irina Kitiashvili (NASA Ames Research Center)
    09/03/2015, 16:10
    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.
    Go to contribution page
  4. 273. Joy's law revisited by using the new Debrecen tilt angle database
    András Ludmány (MTA Debrecen Heliophysical Observatory)
    09/03/2015, 16:50
    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...
    Go to contribution page
  5. 321. Discussion on the topics of the first day
    Rainer Arlt
    09/03/2015, 17:10
  6. 269. Towards understanding the subsurface structure of sunspots
    Hannah Schunker (Max Planck Institute for Solar System Research)
    10/03/2015, 09:00
    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...
    Go to contribution page
  7. 272. Properties of sunspot formation as seen from high-resolution observations
    Nazaret Bello Gonzalez (Kiepenheuer-Institut fuer Sonnenphysik)
    10/03/2015, 09:40
    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...
    Go to contribution page
  8. 287. Examining the relationship between buoyant velocity and magnetic field of an emerging active region
    Chia-Hsien Lin (National Central University)
    10/03/2015, 10:00
    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...
    Go to contribution page
  9. 281. Flux emergence: simulations and observations
    Bob Stein (Michigan State University)
    10/03/2015, 10:50
    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...
    Go to contribution page
Building timetable...