Why are we seeing so many stunning Northern Lights displays in the UK?

This shot of the Aurora Borealis was taken from north Norfolk on 24 March. Credit: Chris Bell

Social media has been alight in recent weeks with images of the Northern Lights across the UK - with stunning displays seemingly becoming more common. But why are we seeing more of one of nature's most magical sights?

A solar flare that left the sun on approximately 22 March took two days to travel before colliding with the earth's atmosphere, creating a display of Northern Lights across the UK.

Unusually, the Northern Lights were seen as far south as Cornwall - and scientists say that we are more likely to see the Northern Lights over the next few years.

The best places to see 'Aurora Borealis'

The Northern Lights or the Aurora Borealis are a stunning display of colours in the night sky ranging from pale green and pink, to shades of red, yellow, blue and violet.

A strong geomagnetic storm results in vibrant and rich displays of these colours.

They are best viewed with no cloud cover, light pollution and little or no moon and facing north in the Northern Hemisphere (and south in the Southern Hemisphere).

If you live across Scotland or further north you will most likely see them many times in your lifetime, but they are a bit more of a treat south of Scotland. In recent days, they have seen as far south as Cornwall.

The Northern Lights on 24 March in Long Stratton in south Norfolk Credit: Dan Holley

When do we see the Northern Lights ?

The Northern Lights normally occur a few days after a solar storm when a Coronal Mass Ejection (CME) takes place.

It's perhaps more easy to imagine an explosion of plasma from the sun results in plasma particles travelling in the direction of the Earth.

The particles from the explosion interact with the Earth's atmosphere in a violent storm in the upper atmosphere and this is what creates the stunning light display.

They are located anywhere from 50 miles high to 400 miles in the Earth's upper atmosphere. (Most of our day-to-day weather occurs in just the top 6 miles of the atmosphere.)

How do you forecast the Northern Lights?

The Northern Lights are forecast using space weather.

The Met Office describe space weather as "changing environmental conditions in near-Earth space", when magnetic fields, radiation, particles and matter, which have been ejected from the Sun, interact with the Earth’s upper atmosphere and surrounding magnetic field.

This can produce a variety of effects from a stunning display of the Northern Lights to disrupting satellite communications.

The Met Office produce a daily space weather forecast and can be found here.

The Northern Lights on Friday lit up the north Norfolk Coast. Credit: @GPearsonJPEGs

Why are we likely to see the Northern Lights more often?

The Sun has a roughly 11-year solar cycle, from one peak to the next in activity.

The peak in the number and frequency of sunspots is referred to as solar maximum, while the period during which we see the fewest sunspots is known as solar minimum. 

Sunspots are where the CMEs originate from, so the more sunspots there are, the more likely they are to reach the Earth's atmosphere - creating conditions that will result in a stunning display of the Northern Lights.

Experts at The Met Office say we are approaching the peak of the sun cycle, meaning we will see more sun spots and therefore more geo-magnetic storms.

"The last solar minimum occurred in December 2019, with the next solar maximum expected around 2025," said a spokesperson. 

"Over the coming years, as we continue towards solar maximum, we can expect to see an increase in the frequency of space weather events.

"On top of this, we tend to see 'seasons' in the form of semi-annual variations of geomagnetic activity, with peaks around the spring and autumn equinoxes often resulting in enhanced auroral activity."

The Northern Lights, as seen from as far south as Bury St Edmunds in Suffolk. Credit: Jackie Gillman-Dace

The Northern Lights across the UK

During the early hours of 24 March, the Northern Lights could be viewed across much of the UK.

The cause of this particular storm was the arrival of two or three coronal mass ejections that left the Sun around 22 March. These powerful blasts of plasma caused the geomagnetic storms that meant the Northern Lights could be viewed as far south as Cornwall.

The strength of the storm was measured as a G4, which is a classed as a moderate storm but it is powerful enough that the Northern Lights were seen across the whole of the UK.

The storms normally wane over about 24 - 36 hours and the effects become less.

What else can cause the Northern Lights?

Coronal mass ejections are not the only way in which the Aurora Borealis is formed.

A coronal hole can also send particles on a solar wind to interact with the earth's atmosphere, resulting in further sightings.