CORRESPONDENCE BETWEEN FIELD-ALIGNED CURRENTS OBSERVED BY ULYSSES ANDHST AURORAL EMISSION

Auroral emission is direct evidence for the magnetosphere/ionosphere c oupling which exists for a magnetised planet such as Jupiter. This cou pling takes place by way of momentum transfer which occurs via field a ligned currents. The driving mechanism for the auroral emission is cha rged particle precipitation along the held lines. During the Ulysses f lyby of Jupiter in February 1992 high latitude auroral events were rec orded by the Faint Object Camera on the Hubble Space Telescope using d irect imaging of UV emissions. Measurements of magnetospheric held ali gned current signatures were recorded by the dual fluxgate/vector heli um magnetometer onboard the Ulysses spacecraft on the same day as the auroral emissions. A correspondence is found to occur between the locu s of auroral emission on Jupiter and the oval traced onto the auroral region by projection of the observed interval of field aligned current s. The field line mapping used to establish this correspondence is per formed using a magnetospheric field model tailored to the conditions o bserved during the Ulysses flyby. (C) 1998 Elsevier Science Ltd. All r ights reserved.