HR: 1330h
AN: SH42C-0550    [PDF]
TI: Comparison Between Interplanetary Scintillation Observation and In-Situ Measurement From 1991 to 2002
AU: * Fujiki, K
EM: fujiki@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, 442-8507 Japan
AU: Kojima, M
EM: kojima@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, 442-8507 Japan
AU: Tokumaru, M
EM: tokumaru@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, 442-8507 Japan
AU: Baba, D
EM: baba@stelab.nagoya-u.ac.jp
AF: Solar-Terrestrial Environment Laboratory, Nagoya University, 3-13, Honohara, Toyokawa, 442-8507 Japan
AB: Interplanetary scintillation (IPS) is a phenomenon that is unique and allows one to measure solar wind velocities over a wide spatial range of interplanetary space where in-situ measurements are impossible or difficult. We have been observing the solar wind velocity structure using the IPS facility (327 MHz) in Japan throughout solar cycles 22-23. To observe the continuously-changing solar wind structure, we apply a newly developed computer-assisted tomography (time-series tomography) to IPS data and then compare the velocity structure obtained by this new method with various in-situ measurements (i.e. WIND, ACE, Ulysses etc.) in the years from 1991 to 2002, to check the reliability of the time-series tomography. As a result, a high-level of agreement between IPS and in-situ measurements has been seen throughout cycles 22-23. We, therefore, conclude that this new technique is highly reliable. We, next, statistically study the variation of the solar wind structure during this period using parameters such as the NS asymmetry, variation of the ratio of fast to slow solar wind component and behavior of the fast solar wind during the solar maximum. We report the results of these analyses in this paper.
DE: 2162 Solar cycle variations (7536)
DE: 2164 Solar wind plasma
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting