Premium
Disappearance of the heliospheric sector structure at Ulysses
Author(s) -
Smith E. J.,
Neugebauer M.,
Balogh A.,
Bame S. J.,
Erdös G.,
Forsyth R. J.,
Goldstein B. E.,
Phillips J. L.,
Tsurutani B. T.
Publication year - 1993
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/93gl02632
Subject(s) - heliospheric current sheet , heliosphere , physics , latitude , solar wind , current sheet , tilt (camera) , astronomy , solar rotation , low latitude , solar cycle , astrophysics , solar physics , magnetic field , magnetohydrodynamics , geometry , mathematics , quantum mechanics
In May, 1993, the heliospheric current sheet (HCS) ceased to be seen by the Ulysses spacecraft at a heliocentric latitude of ∼30° S and distance of 4.7 AU. The disappearance of the HCS coincided with the solar wind speed remaining >560 km/s and with the disappearance of one of four interaction regions previously seen on each solar rotation. The heliographic latitude of the disappearance of the HCS at Ulysses was 11° equatorward of the latitude of the magnetic neutral sheet computed at the source surface at 2.5 solar radii, and it occurred a half year earlier than predicted on the basis of the persistence of the time profile of the neutral sheet tilt from one solar cycle to the next.