Connecting the sun and the solar wind: Comparison of the latitudinal profiles of coronal and Ulysses measurements of the fast wind

A quantitative comparison of the latitudinal profile of polarized brightnes s (pB) measurements nearest the Sun at 1.15 R. by the Mauna Loa Solar Obser vatory K-Coronameter and Ulysses interplanetary measurements of the fast so lar wind during its first south polar pass, at the declining phase of the s olar cycle, is made for the first time to identify the sources of the fast solar wind in the context of coronal density structure. Both profiles are f ound to have the same shape. At the Sun, the minimum coincides with the rad ial extension of the coronal hole boundaries. The slight rise and plateau f ollowing this minimum toward lower latitudes are identified with the corona l extension of the quiet Sun. The corresponding profile of the in situ meas ured velocity has a maximum within the angular extent of the polar coronal hole and decreases gradually beyond its boundaries. The latitudinal profile of the proton flux mimics the density profile, implying that the mass-loss rate is lowest within the angular extent of the polar coronal hole. The as sociation of the fast wind with a density profile that reflects the polar c oronal hole and the surrounding quiet Sun suggests that the fast wind obser ved by Ulysses originates from both regions. That these conclusions differ from earlier published analyses of the same Ulysses measurements is a conse quence of the quantitative and systematic comparison made between Ulysses a nd coronal measurements at 1.15 R..