How DSCOVR Helps Prediction of Geomagnetic Storm

Recent G5 Extreme Geomagnetic Storm with disruption of HF propagation led to discussions on prediction of geomagnetic storms. Deep Space Climate Observatory, or DSCOVR launched in 2015 allows real-time solar wind monitoring which is important in space weather alerts and forecasts. We know that geomagnetic storms have the potential to disrupt major public infrastructure systems including power grids, aviation and global positioning system which is widely used for navigation. DSCOVR has an L1 orbit which is about 1 million miles from the Earth and is the gravity neutral point between Earth and Sun.

Satellites at Lagrange points have stable position with minimum fuel requirement for orbit corrections needed maintain the orbit. Position of DSCOVR is about 1% of the distance from Earth to Sun. The constant stream of particles from the Sun known as solar wind reaches L1 point up to an hour before reaching the Earth. That is how DCOVR is useful in predicting space weather events and geomagnetic storms. Average speed of solar wind is about 400 km/s or about 1 million miles per hour, corresponding to the distance from L1 point to Earth. The temperature of the corona of the Sun is so high that gravity cannot hold the particles which stream out in all directions.