September 17, 2010, 12:00 pm - 1:00 pm

September 17, 2010, 12:00 pm - 1:00 pm

Modeling Coronal Streamers and the Slow Solar Wind at Solar Minimum

Leon Ofman (CUA/NASA GSFC)

During solar minimum the slow solar wind is mainly associated with coronal streamer belt, consisting of closed and open magnetic field regions dominated by a dipole. The results of MHD and multi-fluid models of the solar wind in coronal streamers with empirical heating and acceleration functions will be presented. The models describes electrons, protons, and heavy ions as coupled fluids that are heated by species-specific heating processes with the parameters constrained by observations. The results of the model are compared to the slow solar wind plasma parameters obtained in the extended corona by the UV spectroscopic data from the Ultraviolet Coronagraph Spectrometer (UVCS) on-board SOHO during the past minimum of solar activity (CR1913). The three-fluid streamer modeling has been extended by considering solar magnetic field configuration relevant for solar minimum conditions, and by including preferential heating for heavy ions. The electron density reconstructed from STEREO Cor1 observations of the recent minimum corona is used for additional validation of the model. The plasma parameters from the multi-fluid model were used to compute the expected UV observables from HI Ly-alpha and O VI 1032A spectral lines and the results were compared in details with the UVCS measurements, showing good agreement. The results of the study provide insight on the acceleration and heating regions of the multi-ion slow solar wind.