OBSERVATIONS OF LONG-LIVED SOLAR-WIND STREAMS DURING 1990-1993

Interplanetary scintillation (IPS) can be used to identify changes in solar wind parameters over a wide range in heliographic latitude and e longation and constrain models of its large-scale structure, velocity and density. this paper reviews the scintillation density mapping meth od specifically, and presents over three years of data taken between M arch 1990 and September 1993 with the 3.6 hectare array in Cambridge. A novel form of synoptic plot that is particularly sensitive to corota ting structures is introduced, and low-density streams are identified by their unequivocal signatures within it. Stable corotating structure s are evident throughout - even during the active phase of the solar-c ycle - and specific periods are examined. Density measurements inferre d from scintillation are compared with IMP-8 data for the same period and are shown to be in good agreement, giving further support to the s cintillation/density relationship determined by Tappin (1986).