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J. Geophys. Res. 103 (A6):12049-12067, 1998.
© American Geophysical Union
Heliospheric tomography using interplanetary scintillation observations.
1. Combined Nagoya and Cambridge data.
B.V. Jackson and P. Hick
Center for Astrophysics and Space Sciences
University of California San Diego, La Jolla, California, USA
M. Kojima and A. Yokobe
Solar-Terrestrial Environment Laboratory, Nagoya University, Toyokawa, Japan
Abstract
The authors have produced a computer assisted tomography program that
optimizes a three-dimensional model to fit observational data. They
have used this program with interplanetary scintillation data from
Nagoya, Japan, and Cambridge, England. The program iterates to a least
squares solution fit of observed data using solar rotation and solar wind
motion to provide perspective views of each point in space accessible to
the observations. The authors plot the optimized model as Carrington
maps in velocity V and density for the two data sets with resolutions of
10 degrees in heliographic longitude and latitude. They map the model
to 1 AU and compare this to in situ observations from the IMP spacecraft.
From this comparison they find dNe
varies as Ne0.3. They plot Carrington maps
extrapolated to the solar surface to compare with Yohkoh Soft X ray
Telescope (SXT), Sacramento Peak green line, and Mark III K-coronameter
observations. High velocities modeled at the solar surface for individual
rotations trace coronal holes (including polar ones) observed in SXT data.
Regions of high density modeled from the Cambridge scintillation level data
generally show a high correlation with regions of high solar activity
observed as bright in Yohkoh SXT and green line observations. There is
also a general correspondence of the regions of high density and the
areas which are bright in K-coronameter observations.
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