Speaker
Senthamizh Pavai Valliappan
(Leibniz Institute for Astrophysics)
Description
The long term properties of sunspots aid us in better
understanding of the relation between solar dynamo and
surface magnetic fields, polar fields and open flux. The
continuous observation of sunspots are not available before
1825 but sunspot numbers are available back to 1610.
Reconstruction methods are available to derive the sunspot
butterfly diagram from sunspot numbers. Studying long term
solar cycle properties and updating the reconstruction
method would lead to an efficient way of reproducing sunspot
emergence. Analysing historical observations of sunspots
would contribute more to the properties of sunspots. Samuel
Heinrich Schwabe has recorded his observations of the Sun
during 1825 - 1867, which have been digitized and the
positions and sizes of sunspots were obtained from that.
With that, the physical areas of sunspots and tilt angles of
the sunspot groups were calculated for that period. The
reconstruction method was then tested for Schwabe data and
found to reproduce the butterfly diagram. The evolution of
magnetic field on the surface of the Sun were then derived
using a Surface Flux Transport Model.
Primary author
Senthamizh Pavai Valliappan
(Leibniz Institute for Astrophysics)
