TY - JOUR
T1 - Velocity observations at high latitude and the acceleration phenomena
AU - Kojima, M.
AU - Asai, K.
AU - Kozuka, Y.
AU - Misawa, H.
AU - Watanabe, H.
AU - Yamauchi, Y.
N1 - Funding Information:
We especially thank Wm. A. Coles, UCSD, for providing the IPS data observed with the VHF antenna system of UCSD and with the European Incoherent Scatter (EISCAT) facility at a frequency of 931.5 MHz. We wish to thank R. Esser for her critical and valuable remarks about this work. We would like to acknowledge engineering supports by Y. Ishida, K. Maruyama and N. Yoshimi, and to thank M. Yoshida for her assistancei n data analysis. This researchw as supported by the Scientific Research Fund of the Ministry of Education, Culture, and Science (grant 04640424).
PY - 1995
Y1 - 1995
N2 - Interplanetary scintillation (IPS) observations of polar solar wind streams are discussed. The IPS observed several streams which show low speeds (≤400 km/s) inside of 0.3 AU and high speeds (≥700 km/s) outside of 0.3 AU. The foot points of these streams were located in the HeI coronal holes or at their boundaries. Since the IPS measurements are indirect measurements of the solar wind speed, the derived speeds might be biased by one or several mechanisms. We investigate whether the discrepancy between the observations inside and outside of 0.3 AU can be explained by the geometry of low and high speed regions along the line of sight. We also investigate the effect of changing the turbulence level of the electron density, and finally, by comparing observations from different antenna systems, we discuss the effect of the transition from the weak to strong scattering region.
AB - Interplanetary scintillation (IPS) observations of polar solar wind streams are discussed. The IPS observed several streams which show low speeds (≤400 km/s) inside of 0.3 AU and high speeds (≥700 km/s) outside of 0.3 AU. The foot points of these streams were located in the HeI coronal holes or at their boundaries. Since the IPS measurements are indirect measurements of the solar wind speed, the derived speeds might be biased by one or several mechanisms. We investigate whether the discrepancy between the observations inside and outside of 0.3 AU can be explained by the geometry of low and high speed regions along the line of sight. We also investigate the effect of changing the turbulence level of the electron density, and finally, by comparing observations from different antenna systems, we discuss the effect of the transition from the weak to strong scattering region.
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U2 - 10.1016/0273-1177(95)00320-E
DO - 10.1016/0273-1177(95)00320-E
M3 - Article
AN - SCOPUS:0346821727
SN - 0273-1177
VL - 16
SP - 101
EP - 110
JO - Life sciences and space research
JF - Life sciences and space research
IS - 9
ER -