HR: 1330h
AN: SH13A-05    [Abstracts]
TI: A Comparison of Solar Wind Speeds from a Source Surface Model and Comet Ion-Tail Observations
AU: Jones, G
EM: Geraint.H.Jones@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: * Morrill, J
EM: morrill@shogun.nrl.navy.mil
AF: Naval Research Laboratory, E. O. Hulburt Center for Space Research, Washington DC, DC 20375-5352 United States
AU: Hammer, D
EM: hammerd_2@yahoo.com
AF: The Johns Hopkins University, Department of Physics and Astronomy 3400 N. Charles St., Baltimore, MD 21218 United States
AU: Lawrence, G
EM: gareth.lawrence@oma.be
AF: Royal Observatory Belgium, Av. Circulaire, 3 - Ringlaan 3, Brussels, Belgium
AU: Wang, Y
EM: ywang@pinoak.nrl.navy.mil
AF: Naval Research Laboratory, E. O. Hulburt Center for Space Research, Washington DC, DC 20375-5352 United States
AB: During February 2003 Comet C/2002 V1 (NEAT) passed through the field-of-view (FOV) of the LASCO C3 coronagraph onboard SOHO. The comet passed within 0.1 AU (about 20 solar radii) of the Sun and displayed complex dust and ion tails. Observations of the comet's ion tail orientation have been used to estimate the solar wind speed while in the C3 FOV. We have used the Wang-Sheeley model to estimate the solar wind speed in the vicinity of the comet for comparison with the ion-tail results. The comet's orbit combined with solar rotation produced a comet track along the source surface at nearly constant Carrington longitude and heliographic latitudes ranging from 70 North to 40 South. Photospheric magnetic field maps from Carrington Rotation 1999 measured at three observatories (Wilcox, Kitt Peak, and Mt. Wilson) were used as inputs to the Wang-Sheeley model and each gave different placements of the current sheet. Two of the model results (Wilcox and Kitt Peak) placed the current sheet at similar latitudes (40-45 degrees North) while the third (Mt. Wilson) placed the current sheet at lower latitudes (20 degrees) and appeared to agreed with the current sheet placement implied by the ion-tail results. In this presentation we will discuss the methods of solar wind speed determination from ion-tail observations, present the comparison of solar wind speeds derived from the ion tail measurements with values derived from magnetic field observations, and discuss differences in photospheric magnetic field maps that could affect the location of the current sheet.
DE: 2169 Sources of the solar wind
DE: 7509 Corona
DE: 7536 Solar activity cycle (2162)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2005 Joint Assembly