A physics-based method for predicting imminent large solar flares

Predicting large solar flares through a critical condition of magnetohydrodynamic instability.


Solar flares are an explosion of energy caused by tangling, crossing, or reorganizing of magnetic field lines near sunspots. Solar flares release a lot of radiation into space. If a solar flare is very intense, the radiation it releases can interfere with our radio communications here on Earth.

The X-ray light emitted by a flare, and the ejection of material from the Sun that often accompanies them can produce powerful space weather effects on Earth. These can pose hazards to astronauts, spacecraft, and technological systems on the ground, such as electric power grids and radio communications.

As global society turns out to be more dependent on these technologies, there is an increasing need for reliable techniques to anticipate imminent solar events and improve cautioning times when they happen. In spite of many years of study and near persistent monitoring of the solar’s magnetic activity, the specific conditions and mechanisms that produce flares remain unknown, making them especially difficult to gauge.

Kanya Kusano and colleagues presented a new model called ‘κ-scheme (kappa-scheme) to forecast large solar flares more reliably than previous methods. This physics-based scheme predicts when a large solar flare is imminent using routine magnetic observations of the Sun.

It derives critical thresholds of a magnetohydrodynamic instability. It also identifies where the flare will occur and how much energy could be released.

Scientists tested the model by analyzing data from NASA’s Solar Dynamics Observatory from 2008 to 2019, finding that the κ-scheme was able to identify the occurrence, location, and size of most large flares, up to 20 hours in advance.

Journal Reference:
  1. Kanya Kusano et al. A physics-based method that can predict imminent large solar flares. DOI: 10.1126/science.aaz2511