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Oskar Klein Auditorium, Roslagstullsbacken 21, level 4.
Nordita, Stockholm, Sweden
Scientific recording of sunspots started with Galileo in 1609.
Since Hale (1908) we know that sunspots are strong concentrations
of magnetic field of up to 4000 gauss.
They could be formed by subsurface magnetic flux tubes piercing the surface.
Meanwhile, numerical simulations by many different groups
suggest that strong magnetic fields could be generated in the bulk
of the convection zone.
This would mean that sufficiently
strong magnetic fields may be generated not far from the surface.
However, at the surface the magnetic field appears to be
strongly concentrated into only a few isolated spots - in stark
contrast to the more diffuse magnetic field beneath the surface.
This is still a mystery.
Scientific Organizing Committee
The detailed plan of the meeting has been established by the
Scientific Organizing Committee including
Axel Brandenburg (PI, Nordita),
Mark Cheung (Lockheed, Palo Alto),
Laurent Gizon (MPS, Göttingen),
Petri Käpylä (Helsinki University),
Alexander Kosovichev (Big Bear),
Åke Nordlund (NBI),
Matthias Rempel (HAO/NCAR),
Göran Scharmer (Co-PI, Stockholm University),
Alexandra Tritschler (NSO, New Mexico), and
Jörn Warnecke (MPS, Göttingen).
Local Organizing Committee
Illa R. Losada (Chair, Nordita and Stockholm University),
Sarah Jabbari (Nordita and Stockholm University),
Bidya Binay Karak (Nordita),
Hiva Pazira (Stockholm University),
Nishant Singh (Nordita),
Tine Libbrecht (Stockholm University),
Carolina Robustini (Stockholm University),
Anne Jifält (Nordita, conference secretary),
and also Elizabeth Yang (Nordita, conference secretary).
Scope of the meeting
To set the scene, the meeting will start with a session on
global properties of the Sun's magnetic field.
Next, we need to discuss
observational constraints and results from global helioseismology.
This will lead to the consideration of what causes
flux emergence from an observational and theoretical point of view.
There are conflicting ideas about deep seated versus distributed
magnetic field generation in the Sun that need to be highlighted.
Next, we focus on local magnetic flux concentrations.
There are new theoretical results that can potentially be checked
using local helioseismology.
One of the particular characteristics of sunspots are
surface effects relevant to spot formation.
There are new ideas about enhanced cooling mechanisms relevant
to spot formation.
The region around sunspots, i.e., the so-called penumbra, is another
important example that demonstrates the interaction of magnetic
fields with convection.
The importance of magnetic effects is also evidenced by the
occurrence of umbral dots and light bridges.
Finally, we open the forum to discuss opposing views on sunspot formation
and try a reach a coherent picture of solar activity.
Invited speakers (confirmed)
Karel Schrijver, Lockheed, Palo Alto (session 1)
Tom Duvall, Goddard & Göttingen (session 2)
Bob Stein, Michigan State Univ. (session 3)
Irina Kitiashvili, CTR, Stanford (session 3)
Aaron Birch, MPS, Göttingen (session 5)
Yuhong Fan, HAO, Boulder (session 4)
Hotta Hideyuki, HAO, Boulder (session 4)
Junwei Zhao, Stanford (session 5)
Hannah Schunker, MPS, Göttingen (session 5)
Robert Cameron, MPS, Göttingen (session 6)
Rolf Schlichenmaier, KIS, Freiburg (session 7)
Matthias Rempel, HAO, Boulder (session 7)
Mark Cheung, Lockheed, Palo Alto (session 9)
+ others (to be confirmed)
We plan to organize 8 sessions with talks and discussions and one last
In each of the session we will try to have observational, theoretical and
simulation points of view. Most of the talks will be 30 minutes long.
Additional contributions will be accommodated as shorter talks or posters.
There will be a discussion session at the end of each day.
The topics for each day include:
Monday am: Session 1.
Global properties of the Sun's magnetic field
Monday pm: Session 2.
Observational constraints and results from global helioseismology
Tuesday am: Session 3.
Flux emergence: observational and theoretical results
Tuesday pm: Session 4.
Deep seated vs. distributed magnetic field generation in the Sun
Wednesday am: Session 5.
Local flux concentration: theoretical results and local helioseismology
Wednesday pm: Session 6.
Surface effects relevant to spot formation. Cooling mechanisms
Thursday am: Session 7.
Penumbra formation. Magnetic effects, umbral dots, light bridges, etc.
Thursday pm: Session 8.
Opposing views on sunspot formation.
Friday: Session 9.
Coherent picture of solar activity.
Registration deadline (extended): 23 January 2015
Registration fee: 2000 SEK/214.4 EUR/240.42 US Dollar
The registration fee includes lunches, conference dinner and excursion.
Payment method : bank tranfer.
Please, it is very important to write the reference number, your name (or surname)
and the code of the conference "SUNSPOT2015”. E.g.:
Ref: “4940165 Foo Bar SUNSPOT2015”
Bankgiro 5050-0206 (Danske bank)
Bank: Swedbank, 10534 Stockholm
PhD students and young Postdoc fellows are eligible for travel grants to participate in the program. If you are interested in such a grant, please mark the corresponding field in the application form, briefly summarize your interest in the program in the comments field, and indicate an estimation of your expected travel expenses. Since only a limited number of grants is available, decision concerning the grants will be made on a case-by-case basis and you will be notified shortly after the application deadline.
Reduced rates are available at Arcadia Hotel and
If you need help, please contact the conference secretary
(alternatively Elizabeth Yang).