Remote sensing of the termination of the solar wind via in situ plasma measurements

Abstract

Since 1983 the Plasma Wave experiments on the two Voyager spacecraft have detected low frequency radio noise in the outer heliosphere which has been postulated to emanate from the terminal shock of the solar wind or, possibly, from the heliopause itself. We have examined the solar wind data from the Plasma Science experiment on the Voyager spacecraft to search for correlations with these radio emissions. We find that two anomalous high speed streams passed Voyager 2 in late 1982 and early 1983 and suggest that the interaction of the streams with the heliospheric terminal shock is responsible for the generation of the most intense radio noise observed later in the same year. If the stream speeds did not decrease in traveling to the interaction region, that region is ∼135 A.U. from the sun. This is consistent with previous estimates of the distance to the inner heliospheric shock.