ULYSSES OBSERVATIONS OF SOLAR-WIND PLASMA PARAMETERS IN THE ECLIPTIC FROM 1.4-AU TO 5.4-AU AND OUT OF THE ECLIPTIC

We report observations of radial and latitudinal gradients of Ulysses plasma parameters. The solar wind velocity increased rapidly with latitude from 0 degrees to 35 degrees, then remained approximately constant at higher latitudes. Solar wind density decreased rapidly from 0 degrees to 35 degrees of latitude, and also was approximately constant beyond that latitude. The mass flux similarly decreased away from the equator (but less than the density), whereas the momentum flux was relatively constant. The radial gradient of the entropy at high latitude indicated a value for the polytrope index of about 1.72 (close to adiabatic); the in-ecliptic estimates of radial gradients for temperature and entropy may be biased by temporal variation. A striking increase in the alpha particle-proton velocity difference with latitude is found.