On the role of empirical boundary conditions in space weather prediction results

Abstract

Prediction of the conditions in the near-Earth space environment (space weather) is an urgent scientific and practical task, and there are several scientific teams in the world which have been deeply involved in this research using various model assumptions. One of the most important problems in such calculations is the reliability of the initial data – synoptic maps of the solar magnetic fields. The most famous Space Weather Prediction Center (SWPC) uses observations of the Global Oscillations Network Group (GONG). However, there are other sources of measurements of the full-disk solar magnetic fields (WSO, SDO/HMI and SOLIS in the USA, IRmag at Mitaka in Japan, SMAT in China, STOPs in Russia), and it is of interest to use them to calculate the parameters of the solar wind. In this paper this is done on the example of Carrington Rotation (CR) 2164 using observations from Wilcox Solar Observatory (WSO), GONG, Solar Telescope for Operative Prediction (STOP) at the Sayan Solar Observatory (SSO). The calculations are based on the Wang-Sheeley-Arge (WSA) model and include the determination of the parameters of the coronal magnetic field in the Potential Field Source Surface (PFSS) approximation. The propagation of the solar wind to Earth’s orbit is calculated using the HUX (Heliospheric Upwind eXtrapolation) model. It is shown that the differences in solar wind speeds for different data sets can reach 200 km/s or even more. The results of model simulations are compared with the experimental ACE satellite data.