The Principal Investigator (PI) will perform a computational study of the formation and acceleration of the multi-ion solar wind in coronal streamers. He is motivated by the fact that previous MHD studies that have attempted to describe the solar wind plasma as a single fluid did not reproduce the observed properties of solar wind ions. In this effort, the PI will investigate the solar wind's multi-ion dynamics and compositional variations by developing comprehensive multidimensional and multi-fluid models of coronal streamers that incorporate heavy ions along with protons and electrons as separate but coupled fluids. He will study the effects of preferential heavy-ion heating and ion temperature anisotropies by including empirical heating terms, as well as wave heating and acceleration terms, in his new models. The PI will perform detailed comparisons between his models and available spectroscopic observations by calculating the ultraviolet (UV) emissivity expected from his multi-fluid model output. The computation of coronal emission based on the PI's models will allow him to estimate the expected intensity of UV spectral lines that will be detected using future coronagraphic instruments. This research will lead to a better understanding of the slow solar wind's composition and structure, as well as of the acceleration and heating processes that affect its plasma components.
This project will promote research and education by involving a graduate student who belongs to an underrepresented minority group, as well as by training a postdoctoral scholar. The numerical codes developed in this project will strengthen the nation's computational infrastructure by providing massively parallel multi-fluid models for use by other researchers. The PI's multidimensional, multi-fluid numerical modeling codes will be made available to the broader scientific community for ongoing solar wind research, as well as for other applications where multi-ion plasmas are present, such as in laboratory and astrophysical plasmas.
