Solar Wind Forecast by Using Interplanetary Scintillation Observations

Interplanetary scintillation (IPS) allows us to determine solar wind velocity and density structures over a relatively short time by employing computer assisted tomography. This method can be applied to forecast solar wind changes for a few days prior to its reaching Earth. We have been attempting solar wind forecasting by using IPS data observed at Solar-Terrestrial Environment Laboratory (STELab), Japan. Here we introduce the solar wind forecast using STELab-IPS and evaluated dependences of the accuracy of the STELab-IPS forecasts on a number of line-of-sight observed with IPS and a solar activity by comparing comparing them with in situ measurements.