Composition of Low Energy Interplanetary Ions in the Inner Heliosphere
02 June 2000
The rise to maximum of the 23rd solar cycle finds the Ulysses (ULS) spacecraft on its trajectory to the south pole of the sum while the ACE spacecraft continues to monitor the interplanetary medium sunward of Earth. Low energy interplanetary ions ($sim$0.5 to $sim$8 MeV/ncl) are measured by the composition aperture telecope in each of the twin instruments HI-SCALE and EPAM on ULS and ACE, respectively, For ULS within $sim 30^o$ of the heliosphere equator, we found that the statistical distributions of the relative abundances of the ions at the two locations were similar (Maclenan et. ak., Proc. ACE 2000, in press). We also found that, on a statistical basis, the ion flux times the radial distance at ULS is proportional to the flux as measured at ACE. These results were interpreted in terms of a large parallel diffusion coefficient in the heliosphere inside $sim$5 AU. here, we report on an extension of this study to higher heliographic latitudes as the solar cycle increases in intensity and as ULS approaches the souther solar pole. We remark on implications for the mechanisms for ion propagation to high heliolatitudes during more disturbed interplanetary conditions.