MEASUREMENT OF MAGNETIC HELICITY FLUX INTO THE SOLAR CORONA
Kanya Kusano Submitted: 2003-05-13 00:01
We developed a new methodology which can determine
magnetic helicity flux across
the photosphere based on the magnetograph observation.
In order to derive the helicity flux, first
the velocity tangential
to the solar surface is constructed by applying a correlation tracking
technique on the magnetic observation,
and secondly the velocity component across the photosphere
is derived from the condition that the
magnetic evolution must be consistent with the induction equation.
Through this procedure,
we can determine the helicity flow across the photosphere
as a function of time and space.
Based on this new method, we analyzed magnetic helicity of
the active regions NOAA 9026 and 9077, using the data taken by SOHO/MDI and
the vector magnetograph at NAOJ/Tokyo.
As a result, it was revealed that positive and negative helicity is
supplied in each region simultaneously.
temporary activation of the helicity injection
of the both signs was observed prior to X-class flare events
in the GOES classification.
The investigation on the helicity distribution suggests some
relationship between flare onset and the increase of complexity in the
Authors: K.Kusano, T.Maeshiro, T.Yokoyama, T.Sakurai
Publication Status: COSPAR, Adv. Space Research, in press
Last Modified: 2003-05-13 00:01