Disappearance of the heliospheric sector structure at Ulysses

E. J. Smith, M. Neugebauer, A. Balogh, S. J. Bame, G. Erdős, R. J. Forsyth, B. E. Goldstein, J. L. Phillips, B. T. Tsurutani

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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.

Original languageEnglish
Pages (from-to)2327-2330
Number of pages4
JournalGeophysical Research Letters
Issue number21
Publication statusPublished - 1993


ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Cite this

Smith, E. J., Neugebauer, M., Balogh, A., Bame, S. J., Erdős, G., Forsyth, R. J., Goldstein, B. E., Phillips, J. L., & Tsurutani, B. T. (1993). Disappearance of the heliospheric sector structure at Ulysses. Geophysical Research Letters, 20(21), 2327-2330. https://doi.org/10.1029/93GL02632