Authors: H. Kucharek, F. M. Ipavich, R. Kallenbach, B. Klecker, H. Gruenwaldt,
M. R. Aellig, P. Bochsler
Reference: Spring AGU 1999 in Boston, USA
Abstract:
The solar wind provides the most comprehensive source of information
about solar isotopic abundance. From in situ measurements of the solar
wind one obtains informations on the present-day isotopic composition
of the outer convective zone of the Sun. The flow dynamic of the solar
wind is determined by the magnetic topology of the flux tubes. The slow
solar wind originating from closed field line regions, has a slow bulk
velocity and high freeze-in temperature, and the high speed solar wind
which has a low freeze-in temperature and originates from open flux
tubes in coronal holes. Data from the high resolution Mass
Time-of-Flight spectrometer MTOF on board SOHO have been accumulated
for time periods in which coronal hole or non-coronal hole type plasma
has been detected in order to determine the abundance ratios of
magnesium isotopes in these two different source regions of the solar
wind.