Authors: M. Uzzo, Y. -k. Ko, J. C. Raymond, P. Wurz, and P.
Bochsler
Reference: Astrophys. Jou., 585, 1062-1072, 2003
Abstract:
The purpose of this paper is to explore the observed physical
characteristics of the solar corona streamer belt from 1996 June 1 to
August 5. The UV spectral data was collected by the Ultraviolet
Coronagraph Spectrometer (UVCS) instrument on board the Solar and
Heliospheric Observatory (SOHO) spacecraft. From this data the abundances
of oxygen, silicon, and magnesium were determined on an almost daily basis
during this time period at both the west and east limbs. The streamer belt
was composed of both active and quiescent streamers, which allows for the
comparison of these two categories of magnetic field structures. The
depletion of these three elemental abundances in the core of quiescent
streamers was found, as in previous observations. The variance in
abundance with solar rotation was investigated as a consequence of the
long time frame considered here. The first ionization potential (FIP)
effect was present in the data, and the danger of exploring this phenomena
by the traditional FIP bias was also covered. A comparison with in situ
elemental abundance data from the Charge, Element, and Isotope Analysis
System (CELIAS) instrument on SOHO provides evidence suggesting that
active-region streamers and the outer ``leg'' structural component of
quiescent streamers are definite contributors to the slow solar wind.