Geomagnetic storm warning 'severe' on earth after strong solar flares
The US NOAA bulletin. Possible consequences on power grids and GPS signals, but also great possibilities of northern lights
2' min read
2' min read
A little wow effect, a little alarm. What may happen in the next few hours 149 million km away, and more precisely to the Sun, has forced NOAA (The National Oceanic and Atmospheric Administration) to issue a rather alarming bulletin: 'severe geomagnetic storm (G4)'. A very rare event. The first such warning in the last 19 years, namely since January 2005, when the earth was hit by an unprecedented dose of radiation.
An event that could put a strain on some electronic devices such as GPS, but also parts of power grids, the US agency has announced. And that could trigger several hours of Northern Lights around the globe.
The alarm was triggered after a series of solar flares two days ago (Wednesday 8 May) showed several large plasma ejections from the Sun, paving the way for the geomagnetic storm hypothesis.
What is a solar flare
.A solar flare is a gigantic explosion on the surface of the Sun that releases a huge amount of energy in the form of light and radiation. We can also imagine it as a huge bonfire that releases light, X-rays and even energetic particles into space. These explosions occur in the active regions of the Sun, where the magnetic field is very strong, and are often associated with sunspots.
The main cause of these flares - which are classified according to their intensity from A (the weakest) to X (the most powerful) - is the sudden release of magnetic energy stored in the solar atmosphere. Clearly, the more powerful a flare is, the greater its influence on the Earth.
