2,772 research outputs found
Oscillator models of the solar cycle: Towards the development of inversion methods
This article reviews some of the leading results obtained in solar dynamo
physics by using temporal oscillator models as a tool to interpret
observational data and dynamo model predictions. We discuss how solar
observational data such as the sunspot number is used to infer the leading
quantities responsible for the solar variability during the last few centuries.
Moreover, we discuss the advantages and difficulties of using inversion methods
(or backward methods) over forward methods to interpret the solar dynamo data.
We argue that this approach could help us to have a better insight about the
leading physical processes responsible for solar dynamo, in a similar manner as
helioseismology has helped to achieve a better insight on the thermodynamic
structure and flow dynamics in the Sun's interior.Comment: 28 pages; 16 figures, ISSI Workshop 11-15 November 2013 - The Solar
Cycle, http://www.issibern.ch/program/workshops.htm
Observing and modeling the poloidal and toroidal fields of the solar dynamo
Context. The solar dynamo consists of a process that converts poloidal field
to toroidal field followed by a process which creates new poloidal field from
the toroidal field.
Aims. Our aim is to observe the poloidal and toroidal fields relevant to the
global solar dynamo and see if their evolution is captured by a
Babcock-Leighton dynamo.
Methods. We use synoptic maps of the surface radial field from the KPNSO/VT
and SOLIS observatories to construct the poloidal field as a function of time
and latitude, and Wilcox Solar Observatory and SOHO/MDI full disk images to
infer the longitudinally averaged surface azimuthal field. We show that the
latter is consistent with an estimate of that due to flux emergence and
therefore closely related to the subsurface toroidal field.
Results. We present maps of the poloidal and toroidal magnetic field of the
global solar dynamo. The longitude-averaged azimuthal field observed at the
surface results from flux emergence. At high latitudes this component follows
the radial component of the polar fields with a short time lag (1-3 years). The
lag increases at lower latitudes. The observed evolution of the poloidal and
toroidal magnetic fields is described by the (updated) Babcock-Leighton dynamo
model.Comment: A&
The Origin of Helicity in Solar Active Regions
We present calculations of helicity based on our solar dynamo model and show
that the results are consistent with observational data.Comment: To appear in the Proceedings of IAU Symposium 22
The Magnetic Sun: Reversals and Long-Term Variations
A didactic introduction to current thinking on some aspects of the solar
dynamo is given for geophysicists and planetary scientists.Comment: 17 pages, 9 figures; Space Science Rev., in pres
- …