Officials from the US National Oceanic and Atmospheric Administration have warned that ‘strong geomagnetic storms’ have been observed
The US National Oceanic and Atmospheric Administration (NOAA) has said that the Earth is in the midst of a solar storm, following an expulsion from the sun.
NOAA officials said in an alert that strong geomagnetic storms have been observed, ranking the storm as G3.
This is everything you need to know.
What is a solar storm?
NOAA defines a solar storm, also known as a geomagnetic storm, as a “major disturbance of Earth’s magnetosphere that occurs when there is a very efficient exchange of energy from the solar wind into the space environment surrounding Earth”.
talking to the conversationPiyush Mehta, Assistant Professor of Mechanical and Aerospace Engineering at West Virginia University, says that geomagnetic storms occur “when space weather hits and interacts with the Earth”.
Mehta says: “The sun is always releasing a steady amount of charged particles into space. This is called solar wind. Solar wind also carries with it the solar magnetic field.
“Sometimes, localized fluctuations on the sun will hurl unusually strong bursts of particles in a particular direction. If Earth happens to be in the path of an enhanced solar wind generated by one of these events and gets hit, you get a geomagnetic storm.”
There are two common causes for geomagnetic storms – coronal mass ejections (CME), which refers to explosions of plasma from the surface of the sun, and solar wind that escapes through coronal holes, which are spots of low density in the sun’s outer atmosphere.
Are they dangerous?
These kinds of storms aren’t really that dangerous to us down on Earth’s surface as we’re protected by Earth’s atmosphere – however, geomagnetic storms can be a threat to items orbiting in space, like satellites.
Mehta says that “when the atmosphere absorbs energy from magnetic storms, it heats up and expands upward” which results in the density of the “thermosphere” significantly increasing.
High density means more drag, which poses a problem for satellites. Geomagnetic storms can also disrupt satellites’ ability to communicate with Earth via radio waves.
Many communication technologies around the world depend on radio waves, like GPS for example.
“During geomagnetic storms, changes in the ionosphere – the charged equivalent of the thermosphere that spans roughly the same altitude range – will change how radio waves travel through it,” Mehta says.
“The calibrations in place for a quiet atmosphere become wrong during geomagnetic storms.
“This, for example, makes it difficult to lock onto GPS signals and can throw off the positioning by a few meters.
“For many industries – aviation, maritime, robotics, transportation, farming, military and others – GPS positioning errors of a few meters are simply not tenable.”
NOAA also says: “While the storms create beautiful aurora, they also can disrupt navigation systems such as the Global Navigation Satellite System (GNSS) and create harmful geomagnetic induced currents (GICs) in the power grid and pipelines.”
The strongest geomagnetic storm on record occurred in September 1859, when a mass of particles hit Earth and caused electrical surges in telegraph lines that shocked operators and, in some cases, set telegraph instruments on fire.
Mehta says: “Research suggests that if a geomagnetic storm of this magnitude hit Earth today, it would cause roughly $2 trillion in damage.”
What do the storm rankings mean?
Geomagnetic storms are ranked by NOAA from G1 to G5 based on how minor or extreme said storm is.
- G1, minor
- G2, medium
- G3, strong
- G4, severe
- G5 extreme
G5 storms can cause widespread voltage control problems and result in grid systems experiencing complete collapse or blackouts.
What causes the Northern Lights?
The aurora borealis, also known as the “Northern Lights”, is caused by activity on the surface of the sun.
Solar storms on the sun’s surface give out huge clouds of electrically charged particles, with some of these particles traveling millions of miles and colliding with the Earth.
Royal Observatory astronomer Tom Kerss says “These particles then slam into atoms and molecules in the Earth’s atmosphere and essentially heat them up.
“We call this physical process “excitation”, but it’s very much like heating a gas and making it glow.”
So what we’re seeing when we’re looking at the aurora borealis is the atoms and molecules in our atmosphere colliding with the sun – the characteristic “wavy” patterns of the lights are caused by the lines of force found in the Earth’s magnetic field .
The different colors seen in the aurora borealis is caused by the fact that different gases give off different colors when they’re heated.
The aurora borealis can be seen in the northern hemisphere, hence the “Northern Lights”, and the aurora australis can be found in the southern hemisphere.
In the UK, we can, on occasion, see the aurora borealis – the further north you head, the more likely you are to see the display.