[GTP] GTP/HAO Seminar at NCAR--This week-Steve Cowley

[Silvia Gentile]

How Fast Can Magnetic Fields Be Amplified By Turbulence?
Steve Cowley, UKEA Culham and Imperial College, London

Magnetic fields are observed very early in the evolution of structure of
the universe.  It is not known how or when these fields were created. I 
will discuss
the various theories of the field origin.  These theories challenge our 
present understanding of
Magnetohydrodynamic turbulence.  A central theoretical question is: how 
fast
can magnetic field be amplified by dynamo action.  This question is of 
interest in
many astrophysical situations -- from the sun to galaxy clusters.  Small 
scale fields of observable
amplitudes may be created on short time-scales by  turbulent flows or 
compact objects.
The central issue is the creation of the observed long scale coherence 
in the field.  I will
discuss how dissipation scale dynamics cannot be ignored.  Indeed, it is 
still not clear which aspects of
MHD turbulence are universal and which are problem specific.

May 6, 2009
Time: 1:30pm
Location:  Center Green Laboratory 1, Room 2126