ULYSSES OBSERVATIONS OF THE PLANETARY DEPLETION LAYER AT JUPITER

The repeated samplings of the Jovian magnetosheath during the Ulysses encounter with Jupiter provided an opportunity to probe the planetary depletion layer. Of the 10 complete crossings of the Jovian magnetopau se, only three contained clear signatures of an overlying depletion la yer. All of these occurred on the flanks of the magnetosphere near the dusk terminator; crossings on the dayside were ambiguous or clearly l acked a depletion layer signature. In this paper we present a detailed analysis of the observations by the Ulysses solar wind plasma and mag netometer experiments and discuss conditions favorable and unfavorable for depletion layer observation.