Universe Today
Our Sun is, by everyday standards, a barely believable object. A million Earths could fit inside it. Every second, it converts around four million tonnes of its own mass into pure energy and the light and heat it generates, make life on this planet possible. And yet for all its power, we understand it only imperfectly. Its surface seethes with magnetic complexity, hurling billion tonne clouds of charged particles into space and unleashing radiation bursts powerful enough to fry electronics across an entire hemisphere. We know it does these things. What we've never been able to do particularly well is predict when.
Image artefacts (diffraction spikes and vertical streaks) appearing in a CCD image of a major solar flare due to the excess incident radiation (Credit : NASA Goddard Space Flight Centre)
Imagine receiving a severe weather forecast not hours before a storm hits, but weeks ahead. Time to batten down the hatches, reroute flights, protect critical infrastructure. For hurricanes and blizzards, that kind of foresight is still largely beyond us. But for space weather, scientists have just taken a significant first step toward making it a reality. Researchers at the Southwest Research Institute and the National Science Foundation's National Centre for Atmospheric Research have developed a new forecasting tool that could extend space weather warnings from a matter of hours to potentially weeks in advance. Given that a major solar storm can knock out GPS networks, collapse power grids and endanger astronauts in orbit, the stakes couldn't be higher.
The trouble with predicting solar storms has always been the same that by the time the warning signs appear on the Sun's surface, it's almost too late. The tangled magnetic regions that generate solar flares and coronal mass ejections only become visible a few hours before they unleash their fury. That's barely enough time to do anything useful.
National Centre for Atmospheric Research (NCAR) - Boulder, Colorado.
But those active regions don't appear from nowhere. They bubble up from deep inside the Sun, driven by powerful magnetic forces operating in a thin but critical layer far beneath the surface called the tachocline, the boundary between the Sun's steadily rotating core and the more turbulent churning of its outer layers. If you could peer down there and read what's happening, you'd have weeks of warning. The problem is that the tachocline sits roughly 209,000 kilometres below the surface, you can't see it directly.
The team's solution was actually really rather elegant. Using magnetic measurements from NASA's Solar Dynamics Observatory, they realised that patterns visible at the surface could be mathematically inverted to reconstruct what was happening further down. They then built PINNBARDS; a ‘Physics Informed Neural Network Based Active Region Distribution Simulator’ to do exactly that at scale, connecting surface observations to subsurface magnetic dynamics in ways that weren't previously possible.
It's a hybrid solution with the physical laws governing the Sun's interior encapsulated into an artificial intelligence system that was trained on real solar data. The result is a tool that can potentially identify when and where large, flare producing regions are likely to emerge long before the first magnetic ripple appears at the surface.
Source : New Research Takes First Step Toward Advance Warnings of Space Weather
