What coronal parameters determine solar wind speed?
M. Kojima, M. Tokumaru, K. Fujiki, H. Itoh, T. Murakami, and K. Hakamada
We have been studying physical coronal parameters which
determine solar wind velocity. Coronal hole scale size is
one of them. A large-scale polar coronal hole is a source
of fast solar wind, and medium and slow speed streams originate
in smaller coronal holes. Not only the coronal hole scale size
but also the flux expansion rate and magnetic field energy
determine the wind velocity. However we have revealed that an
individual parameter of the flux expansion rate (f) or the
magnetic field energy (B) does not determine the velocity,
but a combination of them in a ratio B/f determines the velocity.
Correspondence
Masayoshi Kojima, STEL, Nagoya University
presentation
oral