Astrophysicists
find fractal image of Sun’s ‘Storm Season’ imprinted
on Solar Wind
Plasma astrophysicists at the University of Warwick have found that
key information about the Sun’s 'storm season’ is being
broadcast across the solar system in a fractal snapshot imprinted
in the solar wind. This research opens up new ways of looking at both
space weather and the unstable behaviour that affects the operation
of fusion powered power plants.
Fractals, mathematical shapes that retain a complex but
similar patterns at different magnifications, are frequently found in
nature from snowflakes to trees and coastlines. Now Plasma Astrophysicists
in the University of Warwick’s Centre for Fusion, Space and Astrophysics
have devised a new method to detect the same patterns in the solar wind.
The researchers, led by Professor Sandra Chapman, have
also been able to directly tie these fractal patterns to the Sun’s
‘storm season’. The Sun goes through a solar cycle roughly
11 years long. The researchers found the fractal patterns in the solar
wind occur when the Sun was at the peak of this cycle when the solar
corona was at its most active, stormy and complex – sunspot activity,
solar flares etc. When the corona was quieter no fractal patterns were
found in the solar wind only general turbulence.
This means that fractal signature is coming from the complex
magnetic field of the sun.
This new information will help astrophysicists understand
how the solar corona heats the solar wind and the nature of the turbulence
of the Solar Wind with its implications for cosmic ray flux and space
weather.
These techniques used to find and understand the fractal
patterns in the Solar Wind are also being used to assist the quest for
fusion power. Researchers in the University of Warwick’s Centre
for Fusion, Space and Astrophysics (CFSA) are collaborating with scientists
from the EURATOM/UKAEA fusion research programme to measure and understand
fluctuations in the world leading fusion experiment MAST (the Mega Amp
Spherical Tokamak) at Culham. Controlling plasma fluctuations in tokamaks
is important for getting the best performance out of future fusion power
plants.
Notes for Editors:
1. The research by K.Kiyani, S. C. Chapman, B. Hnat, R.
M. Nicol, is entitled "Self- similar signature of the active solar
corona within the inertial range of solar wind turbulence" and
was published on May 18th 2007 in Phys. Rev. Lett.
2. The researchers received support and data from STFC
(previously PPARC), EPSRC, and the NASA WIND, ACE and ULYSSES teams.
For further information please contact:
Professor Sandra C. Chapman, Director
Centre for Fusion, Space and Astrophysics
University of Warwick, www.warwick.ac.uk/go/cfsa/
Tel: 02476 523390 S.C.Chapman@warwick.ac.uk
Peter Dunn, Press and Media Relations Manager,
Communications Office, University of Warwick,
024 76 523708 or 07767 655860 email: p.j.dunn@warwick.ac.uk
PR46 PJD 24th May 2007
