HR: 0800h
AN: SH21A-0276 [Abstracts]
TI: ON THE GLOBAL DISTRIBUTION OF SLOW SOLAR WIND
AU: * Zhao, L
EM: lzh@umich.edu
AF: Department of Atmospheric, Oceanic and Space Sciences, University Michigan, 2455
Hayward St., Ann Arbor, MI 48109-2143, United States
AU: Zurbuchen, T
EM: thomasz@umich.edu
AF: Department of Atmospheric, Oceanic and Space Sciences, University Michigan, 2455
Hayward St., Ann Arbor, MI 48109-2143, United States
AU: Fisk, L
EM: lafisk@umich.edu
AF: Department of Atmospheric, Oceanic and Space Sciences, University Michigan, 2455
Hayward St., Ann Arbor, MI 48109-2143, United States
AB:
The heliosphere is composed of three types of solar wind: solar wind from coronal holes (mostly fast wind), solar
wind associated with streamers (mostly slow wind), and transient interplanetary coronal mass ejections
(ICMEs). In this work, Advanced Composition Explorer (ACE) and Ulysses data from 1997 to 2006 are used to
investigate the properties and relative contributions of these three sources of solar wind during solar cycle 23.
Plasma composition (C6+/C5+, O7+/O6+, Fe/O, average charge state of Fe), moments of the
proton distribution function (density, velocity, and temperature), and the magnetic field are analyzed. The ratio of
O7+/O6+ is used as a criterion to separate ICMEs and the two types of quasi-stationary solar wind
based on the results by Richardson & Cane (2004). Similarly, streamer-associated wind is distinguished from
coronal hole wind based on its compositional signature O7+/O6+. Furthermore, by adding the location
of the heliospheric current sheet from a PFSS model, the ACE and Ulysses data are extrapolated into a global
heliospheric structure at 2.5 solar radii. In these maps, we estimate the normal distance from the origin of
streamer wind and coronal hole wind to the local current sheet and find that streamer wind comes from a band
with width of approximately 23° around the current sheet and coronal hole wind originates from a region
23° beyond the current sheet. This study provides important constraints on the origin of the solar wind and its
relation to the global heliospheric structures. A new theoretical explanation of this distribution of the slow wind
source region is also provided.
DE: 7511 Coronal holes
DE: 7524 Magnetic fields
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting