The identification and characterization of Alfvenic fluctuations in Ulysses data at midlatitudes

Ulysses magnetic held and plasma data recorded during 1992 and 1993 as the spacecraft moved through mid-heliolatitudes, have been used to identify int ervals dominated by Alfvenic fluctuations in the presence of corotating int eraction regions. A wavelet frame representation of Elsasser variables was used to calculate the Alfvenicity of the fluctuations as a function of time and frequency, and to describe their occurrence primarily within trailing edges of the corotating interaction regions that occurred within the interv al. It was confirmed that, in general, if a dominant population of Alfven w aves was present, then these waves were outward propagating, but the power in the waves was found to be highly variable in time. A decrease in the pow er in the Alfven waves was found for frequencies lower than similar to 1 x 10(-5) Hz, corresponding to a scale between 0.3 and 0.5 AU. A dominant popu lation of outward-propagating Alfven waves was typically found to occur dur ing the trailing edge of high-speed streams, as expected from previously pu blished studies, but they did not persist for the whole of the trailing edg e. They generally occurred within the first half and ended in a sharp cutof f across all frequencies. Dominant outward-propagating Alfvenic fluctuation s were also identified during some low-speed streams, but they did not pers ist between rotations. No latitudinal dependence of the purity of the fluct uations was found, but the fluctuations became more persistent at higher la titudes.