Nasa developes tool to predict solar storms 24 hours in advance

Washington: Nasa scientists, including one of Indian-origin, have developed a new model that can help predict solar geomagnetic storms — which can cause telecommunication disruptions and power outages — 24 hours in advance.

Solar geomagnetic storms may be caused by a giant cloud of solar particles, called a coronal mass ejection (CME), aligned in the opposite direction of the Earth’s magnetic field. If a CME is aligned in the same direction as Earth’s — that is, pointing from south to north — the CME will slide by without much effect.

Currently, scientists don’t have much advance notice of how a CME’s magnetic fields are arranged. They can only measure the fields as the CME passes over satellites close to Earth.

“What we have now is effectively only a 30 to 60 minute heads up of a CME’s configuration before it hits Earth’s magnetosphere,” said Neel Savani, a space scientist at Nasa’s Goddard Space Flight Center in Greenbelt, Maryland. Savani has described a new model to measure the magnetic field configuration significantly further ahead of time.

The model is now undergoing testing, but if it’s robust, then scientists might finally have a tool to predict a CME’s magnetic configuration from afar. This means forecasters could give utility grid and satellite operators a full 24-hour advance warning to protect their systems — crucial time to protect their assets.

Savani made use of Nasa’s Solar Dynamics Observatory to observe the magnetic fields of the initial eruption on the Sun. In the past, using such data to predict which direction the CME’s magnetic fields point has not been very successful.

However, Savani realised that earlier attempts simplified the eruptions too much, assuming they came from a single active region — the magnetically complex spots on the Sun that often give rise to solar eruptions. Savani’s new method is able to incorporate the complex reality of CMEs having foot points in more than one active region.

There are no tools to measure the magnetic fields once a CME has moved away from the Sun, but scientists do have ways of watching how the clouds expand, twist and grow as they race into space.

Both Nasa’s Solar Terrestrial Relations Observatory, or STEREO, and the joint ESA/NASA Solar and Heliospheric Observatory, or SOHO, provide these observations using coronagraphs, which can focus in on the CME’s progress by blocking the bright light of the Sun.

By watching how the CME moves and changes in these coronagraphs, Savani’s model tracks how the initial eruption evolves over time.

Ultimately, the model can describe how the CME will be configured as it approaches Earth, and even which parts of the CME will have magnetic fields pointed in which direction.