EISCAT measurements of solar wind velocity and the associated level of interplanetary scintillation

A relative scintillation index can be derived from EISCAT observations of Interplanetary Scintillation (IPS) usually used to study the solar wind velocity. This provides an ideal opportunity to compare reliable measurements of the solar wind velocity derived for a number of points along the line-of-...

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Bibliographic Details
Published in:Annales Geophysicae
Main Authors: Fallows, R. A., Williams, P. J. S., Breen, A. R.
Format: Text
Language:English
Published: 2018
Subjects:
Online Access:https://doi.org/10.5194/angeo-20-1279-2002
https://angeo.copernicus.org/articles/20/1279/2002/
Description
Summary:A relative scintillation index can be derived from EISCAT observations of Interplanetary Scintillation (IPS) usually used to study the solar wind velocity. This provides an ideal opportunity to compare reliable measurements of the solar wind velocity derived for a number of points along the line-of-sight with measurements of the overall level of scintillation. By selecting those occasions where either slow- or fast-stream scattering was dominant, it is shown that at distances from the Sun greater than 30 R S , in both cases the scintillation index fell with increasing distance as a simple power law, typically as R -1.7 . The level of scintillation for slow-stream scattering is found to be 2.3 times the level for fast-stream scattering. Key words. Interplanetary physics (solar wind plasma)