Our main scientific objective is to derive the solar wind speed profile from coordinated SOHO/UVCS and radio scintillation data, over a wide range of heliocentric distances (2 to 50 R_sun), with the terminal wind speed being given by in situ Ulysses data. The goal of this study is twofold: on one side, we will provide the solar community with a composite wind speed vs. heliocentric distance profile based on measurements which refer to the same plasma parcels measured by different experiments at different distances - thanks to the SOHO-Sun-Ulysses quadrature configuration. While this is "per se" a valid objective, the wind profile we will come up to will serve as a benchmark input for the construction of a reference solar minimum heliosphere, as described later in this document.
A further objective we aim to as a by-product of the campaign observations is to get a better understanding of polar plumes morphology and physical conditions, with special emphasis to their temporal variation, practically unknown so far. The role of plumes in solar wind is still to be ascertained, hence, although we will build a wind profile averaged over the plume/interplume plasma in our main objective, we also plan to contribute to a better understanding of the solar wind by investigating polar plumes. Observations from COMP will provide measurements of alfvenic plasma motions and pos magnetic field diagnostics from the limb to 1.4 solar radii in the 10747 and 10830 lines. These measurements will help characterize the magnetic structures present, their inclination and the multitude of wave motions present - essential to understanding the roots of the fast solar wind. |
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