Interplanetary scintillation and plasma density

Observations on a grid of 900-2500 radio sources have been combined with in situ spacecraft measurements to determine the relation between interplanetary scintillation and mean plasma-density along the line of sight. Studies carried out during a variety of disturbances, including shocks and corotating streams, indicate a relation g approx.= (N/9)sup(0.5) where g is the scintillation enhancement factor and N (cm-3) is the plasma density. The results show that scintillation can be used to provide a powerful and reliable method of monitoring the mean density along the line of sight for disturbances of many kinds, including post-shock flows. (author)