1. K. Fujiki, H. Ito, M. Tokumaru Solar-Terrestrial Environment Laboratory (STELab), Nagoya University. SOLAR WIND FORECAST BY USING INTERPLANETARY SCINTILLATION OBSERVATIONS Given by M. M. Bisi Center for Astrophysics and Space Sciences, University of California, San Diego.

2. Earth IPS LOS Real-time tomography analysis Lines of sight fulfill interplanetary space inside 1 AU by observing IPS sources over one solar rotation (left panel).

3. Forecast on Oct 7, 2005. Forecast on Oct 7, 2005. ACE Forecast

4. Quantitative verification of IPS forecast. Quantitative verification of IPS forecast. Forecast Error: Forecast Error: IPS forecasts on July-October, 2005 are compared with ACE data. Cause of the error; Cause of the error;CME; Sunspot number; Number of LOS; etc… Objective Method

5. LOS obtained in Oct 7 mapped on 1AU Earth position Forecastable

6. Forecastable period 7.2 days

7. Differences between IPS forecast and ACE data. Differences between IPS forecast and ACE data. 100km/s

8. | V IPS -V ACE |~ 87.7km/s Averaged difference between IPS and ACE Daily variation of Averaged difference between IPS and ACE

9. Daily variation of correlation coefficient between IPS Forecast and ACE

10. Orange ： high correlation and small difference. Blue ： Low correlation and large difference.

11. Number of LOS during 3 days past. Number of LOS at forecast date Number of LOS is small. IPS Forecast Error and Number of LOS

12. Forecast error does not depend on solar transient activity. Number of CMEs and sunspots during 3 days past. IPS Forecast Error and Transient activities

13. Verifications of IPS solar wind forecast are carried out by using IPS and ACE data obtained from July through October 2005 (near solar minimum). Verifications of IPS solar wind forecast are carried out by using IPS and ACE data obtained from July through October 2005 (near solar minimum). Forecastable period: Forecastable period: 7days (avg.), 13days(max). Good accuracy period: Good accuracy period: ~6days (|V IPS -V ACE |<100km/s). ~6days (|V IPS -V ACE |<100km/s). Stable condition of IPS observations is essentially important to forecast solar wind with good accuracy. Stable condition of IPS observations is essentially important to forecast solar wind with good accuracy. Summary