Working Group 1 report: Solar wind models from the Sun to 1 AU: Constraints by "in situ" and remote sensing measurements

The goal of Working Group 1 was to discuss constraints on solar wind models . The topics for discussion, outlined by Eckart Marsch in his introduction, were: (1) what heats the corona, (2) what is the role of waves, (3) what d etermines the solar wind mass flux, (4) can stationary, multi-fluid models describe the fast and slow solar wind, or (5) do we need time dependent flu id models, kinetic models, and/or MHD models to describe solar wind acceler ation. The discussion in the working group focused on observations of "temperature s" in the corona, mainly in coronal holes, and whether the observations of line broadening should be interpreted as thermal broadening or wave broaden ing. Observations of the coronal electron density and the flow speed in cor onal holes were also discussed. There was only one contribution on observat ions of the distant solar wind, but we can place firm constraints on the so lar wind particle fluxes and asymptotic flow speeds from observations with Ulysses and other spacecraft. Theoretical work on multi-fluid models, highe r-order moment fluid models, and MHD models of the solar wind were also pre sented.