Global patterns of heliospheric magnetic field polarities and elevation angles: 1990 through 1995

From 1990 through 1995, Voyager 1 (V1) moved from 39.9 to 61.7 AU in the distant heliosphere at a latitude of approximate to 32 +/- 1 degrees N. During this period of declining solar activity, the latitudinal extent of the sector zone (the region containing sectors and the heliospheric current sheet) was decreasing. From 1990 through 1992, V1 observed both positive and negative magnetic polarities, indicating that it was ja the sector zone. From 1993 through 1995, V1 observed primarily positive magnetic polarities, indicating that it was above the sector zone. The transition in the V1 polarity distribution at the beginning of 1993 implies that the maximum latitudinal extent of the sector zone was then approximate to 32 degrees N; This transition is related to a decrease in the maximum latitudinal extent of the computed neutral line in the solar corona. The ''classic model'' of the neutral line provides a better description of the V1 polarities than the ''radial model.'' The latitudinal extent of the sector zone was nearly constant from the Sun to 50 AU; A similar transition in the polarity distribution was observed at approximate to 30 degrees S by Ulysses in early 1993 within 5 AU, establishing the minimum latitudinal extent of the sector zone at that time. From 1990 through 1995, hear-Earth spacecraft (which were near the solar equatorial plane, in the middle of the sector zone) observed equal amounts of positive and negative polarities. The bimodal two-polarity distributions observed by Voyager 2 Showed an increasing fraction bf negative polarities as it moved from 2.4 degrees N to 15.1 degrees S and from 31.1 to 47.7 AU. The distribution of elevation angles was gaussian both at V1 in the distant heliosphere and near 1 AU during the each of the years from 1990 through 1995. The width of the distribution did not change significantly at V1 from 1986 through 1995, consistent with little (<5 degrees) or no variation with (1) radial distance from 40 to 62 AU, (2) latitude from 31 degrees to 33 degrees, and (3) the solar cycle. The width of the distribution of elevation angles at 1 AU did vary with Solar activity, being 5 degrees greater at solar maximum than at solar minimum, possibly owing to the extreme north-south fields in many ejecta, which are more frequent near solar maximum.