Coronal radio sounding with Ulysses: solar wind electron density near 0.1AU during the 1995 conjunction.

摘要: Dual-frequency ranging measurements were recorded for a three-week interval during the 1995 solar con- junction of Ulysses spacecraft. The unusual occultation ge- ometryresultingfromthehighinclinationUlyssesorbitenabled coronal radio sounding from South Pole to helio- graphic equator at ray path offsets near 0.1 AU. elec- tron column density along line-of-sight between and Earth, derived differential time delays signals transmitted simultaneously on S-band X-band car- riers, clearly show signatures polar hole streamer belt low latitudes. observations are utilized in this work test models heliographic latitude depen- dence electron inner heliosphere. Tradi- tional activity minimum, whereby decreases rather slowly pole, found fare poorly representing measurements. In contrast, modelbasedonUlyssesin situsolarwindmeasurements,when combined with ancillary derive location theheliosphericcurrentsheet,wasfoundtoprovidesatisfactory agreement data.