Two-step forecast of geomagnetic storm using coronal mass ejection and solar wind condition

Area of Science:

• Space Physics
• Solar-Terrestrial Physics
• Geomagnetism

Background:

• Previous studies utilized coronal mass ejection (CME) parameters for geomagnetic storm forecasting.
• Existing models require enhancement for improved prediction accuracy.

Purpose of the Study:

• To develop and evaluate a two-step geomagnetic storm forecast model.
• To integrate solar wind conditions near Earth with CME parameters for better forecasting.

Main Methods:

• Derived empirical solar wind criteria (B ≤ -5 nT or E ≥ 3 mV/m for t ≥ 2h) for moderate storms (Dst < -50 nT).
• Compared the performance of solar wind criteria and the Temerin-Li (TL) model using 55 CME-Dst pairs (1997-2003).
• Implemented a two-step forecast combining CME and solar wind data.

Main Results:

• Solar wind criteria showed slightly better storm event forecasts (90%) than the TL model (87%).
• The TL model better predicted non-storm events (88%) compared to solar wind criteria (71%).
• The two-step forecast correctly predicted 80% of events missed by CME-only forecasts; the union approach (CME or solar wind) achieved 100% storm forecast accuracy.

Conclusions:

• A two-step forecast integrating CME and solar wind data significantly improves geomagnetic storm prediction.
• The union approach (CME or solar wind conditions) offers a robust method for forecasting all geomagnetic storms.
• Combining multiple data sources enhances the reliability of space weather forecasts.