‘True north’ is the direction to the geographic north pole; ‘grid north’ is where the vertical blue lines shown on Ordnance Survey (OS) maps converge, and ‘magnetic north’ is the direction that a compass needle points as it aligns with the Earth magnetic field.

In November 2022, as all three ‘norths’ aligned and met at a point in Langton Matravers in Dorset, England, for the first time. Now, after three historic years together, new magnetic field data collected by the 51ÁÔÆæ (BGS) and calculations made by OS have shown that the triple alignment is set to leave England at Berwick-upon-Tweed on 13 December 2025 and move into the North Sea. It predicted that the triple alignment will hit land again at the end of October 2026 in Drums, just south of Newburgh in Scotland. After passing through Mintlaw, its last stop in Scotland will be Fraserburgh around mid-December 2026, before it returns to the North Sea.

Once over the North Sea, the three norths are expected to continue northwards before leaving the British national grid. They will also stay in alignment for another couple of years before magnetic north separates from true north and grid north. Magnetic north moves slowly, so it may be several hundred years before this alignment comes around again., when magnetic north became east of grid north for some locations in Great Britain for the first time in more than 350 years. This affected navigators using a compass, who needed to adjust their bearing by subtracting instead of adding the difference between magnetic and grid north.

During the three norths’ time in England, they moved northwards through Poole near the end of 2022, then through Chippenham and Birmingham before reaching Hebden Bridge, West Yorkshire, in October 2024. The triple alignment then passed though the Pennines and will leave England at Berwick-upon-Tweed.

Due to refinement of the underlying models and the prediction data, the alignment progress has slowed slightly since the initial predictions back in 2022. When it crosses the coast at Berwick-upon-Tweed it will have travelled 576km (about 358 miles) in 1127 days so that about 511m per day (or about 5.9 mm per second or about 0.013 miles per hour). It will likely be a very long time before the alignment comes around again.

Mark Greaves, Earth measurement expert at OS.

The three norths combining in Great Britain has been a once-in-a-lifetime occurrence. Although part of geospatial history, there is no impact for navigators, pilots and captains once the alignment leaves, and people will still need to continue to take account of the variation between magnetic north from a compass and grid (or true) north on a map.

It been a privilege to be able to observe this phenomenon over the past few years. The magnetic field is not predictable in the long term, so we don’t know how many hundreds of years it will take for this historic alignment to occur again.

Dr Ciarán Beggan, geophysicist at BGS.

OS and the BGS Geomagnetism team collect detailed measurements of the magnetic field at more than 40 sites around the UK. These enable scientists to create high-resolution maps and make accurate forecasts of the .

Several factors, including changes in the flow of the Earth liquid outer core, the iron content of the local rocks and the variations in the magnetic field that are caused by the Sun, mean these predictions have some uncertainty and are a rough estimation of when the three norths are due to leave British soil.

The 51ÁÔÆæ (BGS) has upgraded its geomagnetic forecast today (12 November 2025) to the highest intensity level amid an ongoing solar storm, which prompted the aurora displays that entertained stargazers across the UK overnight.

Current predictions suggest that a second storm, feeding off the first, will result in potentially the largest solar storm to hit our planet in over two decades. Scientists believe that it has the potential to achieve the maximum level of G5 on the . Dubbed a ‘cannibal storm’, the first event has already disrupted communications and global positioning system (GPS) satellite accuracy. At ground level, it created the biggest measured geoelectric field since BGS records began in 2012.

The increase in activity from the coming storm could have further, significant impacts on space and ground-based technologies, including communication systems, global positioning systems (GPS) and satellite orbits.

Geomagnetic storms are caused by solar activity interacting with the Earth magnetic field, which has implications for national energy infrastructure and navigation. For this reason, it is listed as one of the primary hazards on the UK .

Space weather can have a real impact on the lives of people across the planet. BGS records real-time data of geomagnetic conditions, underpinning the national forecast service. Our data suggests that this event could be one of the biggest storms we’ve seen in 20 years.

Dr Gemma Richardson, BGS Geomagnetic Hazard Specialist.

Like any forecast, it is not possible to say with certainty exactly how big the storm will be. Solar storms travel from the Sun and can reach Earth in as little as 17 hours, although they can also take significantly longer. Based on satellite observations, we anticipate this event will be significant; early indications such as ground measurements of solar energetic particles are some of the largest recorded since 2005.

Assuming clear, dark skies, there is an increased chance of seeing the aurora borealis from the UK tonight. Observers in Scotland, northern England and Northern Ireland have the best chance if the weather is favourable.

Further information

Five UK-made quantum magnetometers are being installed across the UK to provide complete national coverage of the magnetic field for the first time.

Quantum magnetometers are highly sensitive instruments that can detect variations in the Earth’s magnetic field with extreme precision. These new sensors will provide data to BGS that will give scientists a more comprehensive understanding of how the magnetic field changes during extreme magnetic storms. These are the same storms that trigger aurorae like those the UK experienced during May 2024.

During these storms, variations of the geomagnetic field can be large enough to cause localised effects on grounded technology such as power grids, Global Navigation Satellite System (GNSS) receivers and railway signals. Until now, it has not been possible to study these regional variations using the three existing UK geomagnetic observatories. The new quantum magnetometers have been strategically placed around the country to fill in gaps in the national coverage and allow small-scale, local variations to be monitored.

The more that is known about the nature of magnetic storms — how often they occur, how big they can be and how they interact with our natural and artificial environments — the better scientists can advise Government, the public and industry on where the risks are to the technologies we rely on. This allows organisations such as the UK’s power distribution companies to take measures to protect supplies and services against the effects of space weather.

The quantum magnetometers have been developed and optimised by the University of Strathclyde and the Science and Technology Facilities Council (STFC) RAL Space. The sites of these new sensors have been carefully selected across the UK and have been picked for their suitability for detecting magnetic signals with minimal interference. They are installed at:

• Aberystwyth, Ceredigion
• Boulby, Noth Yorkshire
• Blickling, Norfolk
• Chilbolton Observatory, Hampshire
• Thurso, Caithness

We are incredibly excited to be able to study the magnetic field around the UK in greater detail than ever before. The installation of the five new quantum magnetometers will help to fill in the gaps between the existing observatories and will improve our vision of the changes taking place during extreme magnetic storms.

These new measurements will greatly enhance our understanding of how extreme magnetic storms impact different parts of the country. This means that society in general will have access to the advice and information needed to understand where we are vulnerable to magnetic storms and to make informed decisions on how to mitigate against them.

Dr Ciarán Beggan, geophysicist at BGS.

The quantum magnetometers were developed through the , specifically the Quantum Technology Hub in Sensors and Timing. The funding to build and deploy the sensors comes from UK Research and Innovation (51ÁÔÆæ).

A new space weather variation hazard index, developed by BGS researchers using data from the European Space Agency (ESA) Swarm satellite constellation, provides a near-real time, global picture of geomagnetic variations to spot the local effects of space weather.

Space weather can pose significant hazards to satellites and Earth-based technologies. Infrastructure and technology, including global navigation satellite systems, telecommunications and power grids can be disrupted by strong geomagnetic activity.

ESA three Swarm satellites, which measure changes in Earth magnetic field from space, can capture geomagnetic anomalies related to space weather all over the world. Whilst they do not offer the continuous time coverage at a single location that a ground station can offer, the trio global coverage provides our best-ever survey of Earth magnetic field.

Until recently, the data processing pipeline meant that Swarm data was only made available after four days, preventing its use in space weather hazard monitoring. That all changed in 2024 with the introduction of a FAST data processing chain, which makes a lot of the mission data available in close to near-real time – as quickly as three hours after measurement.

The new space weather hazard variation index developed by Lauren and colleagues at the BGS draws on over ten years of Swarm data. Using the mission long-term record of Earth geomagnetic field as a baseline, it is possible to spot sudden variations that depart strongly from the normal or expected level of variation.

All space weather scientists want real-time, global geomagnetic field data. Swarm data isn’t quite real time yet, but it getting closer. We wanted to make sure the techniques were available to make use of the FAST data so that it would be available to space weather scientists in the future.

A big geomagnetic storm might be obvious, but if there was just a little blip over the Atlantic Ocean, and perhaps some aircraft was struggling to communicate, we could use this index to check if there was something more localised that could explain the drop in communications.

Lauren Orr, space weather scientist at BGS.

Space weather monitoring is precisely the sort of application we had in mind for Swarm FAST data, and it is wonderful to see it being used so effectively. It another great example of the applications and benefits the Earth Explorer satellites bring to Europe and the rest of the world.

Anja Strømme, Swarm Mission Manager.

To read the full update on the new hazard index, please visit the .

Without getting into the specifics, coronal mass ejections (CMEs) are common occurrences where a portion of the Sun outer atmosphere is ejected into space, caused by rapid changes in its magnetic field. CMEs often occur along with solar flares, which are unleashed from active regions called sunspots. Last week active sunspot, now rotating out of view of the Earth-facing solar disc, was particularly active, emitting a series of Earth-directed CMEs from mid-early last week.

This series of consecutive solar flares and their associated CMEs arrived in Earth atmosphere in the early evening on 10 May 2024. Amazingly, last week storm is not just any geomagnetic storm; it shares characteristics with a few of the largest storms since 1869, such as the 2003 Hallowe’en geomagnetic storm. 1869 is the year in which geomagnetic global storm index, the aa index, was first used to measure daily geomagnetic activity. The aa is derived from magnetic observatory data.

On the ground, we can continuously and accurately measure magnetic field variations over many years at geomagnetic observatories. In the UK, we have three permanent observatories:

• Lerwick, Shetland
• Eskdalemuir, Dumfries and Galloway
• Hartland, Devon

Other, newer magnetic measuring stations can be found in Northern Ireland, Leicestershire and Herstmonceux.

We would expect variations of the local geomagnetic field to be greatest at Lerwick because it is the northernmost location. Looking at background conditions with no storms, the horizontal magnetic field intensity at Lerwick varies around 30 to 50 nanoTesla (nT). On the evening of the 10 May, the peak variations in horizontal field intensity reached 800 nT!

Usually, with smaller geomagnetic storms, the naked eye is unlikely to observe the aurora at latitudes south of Scotland and that assuming we have clear, dark skies free from light pollution. With this big geomagnetic storm, which still requires a name, many people in large cities across England were able to observe vivid colours on the 10 to 11 May.

Events like last weekend will become useful case studies for scientists to gain a better understanding of the effects of space weather on Earth. This will help to improve our capability to forecast severe space weather events that could be even stronger than the one we recently experienced. More extreme space weather events may cause damages to power grid systems and operational satellites, affecting things like GPS and mobile networks.

While we are not expecting further significant geomagnetic activity this week. As we are approaching solar maximum, further large events such as this one are expected in the coming years.

About the author

The (IGRF), which represents the main or core magnetic field of the Earth, is collaboratively updated by the international geomagnetic community, including . This will be the fourteenth update (IGRF-14) and is due for completion at the end of 2024. IGRF can be used for many purposes, such as navigation by spacecraft that are used for orientation.

In collaboration with the US National Oceanic and Atmospheric Administration, BGS will also update the World Magnetic Model (WMM) at the end of this year. The WMM is a series of magnetic field maps that help underpin commercial navigation systems, such as electronic devices including mobile phones, and is also updated every five years.

The maps require periodic updates because the Earth main magnetic field changes slowly over time, which is caused by flow of the liquid iron in the outer core. Measurements of the magnetic field are made at on the ground and by that orbit around 500 km above the surface. 

The measurements are combined using computers to create two snapshots of the magnetic field: one five years in the past (2020) and the other slightly into the future (2025). The geomagnetic community also makes an estimate of how the magnetic field will change between 2025 and 2030. In 2030, this process will be repeated, in order to forecast to 2035. 

The call for candidate models for IGRF-14 was recently released to the community. The coordination of the release for this generation is led by Dr Ciarán Beggan at BGS and Clemens Kloss at the and will involve dozens of scientists from around the world helping to create the new maps.

These maps are embedded in nearly every mobile phone in the world — that almost 7Ìýbillion devices, which I find amazing to think about.

Ciarán Beggan, BGS Geophysicist.

The 2019 model update showed magnetic north racing across the northern hemisphere at around 50 km per year, as it moved from the Canadian Arctic towards Siberia.

More information

More information on the call for candidate models is available at the .

The aurora is a natural display of light in the night sky, with bands of green, red or purple lights that shimmer and change appearance over time. It is usually seen around the Arctic and Antarctic circles, which are also referred to as ‘auroral zones’.  

The northern lights (or aurora borealis) can often be seen in Alaska, Canada, Iceland, Scandinavia, Finland and Russia, whilst the southern lights, or aurora australis, can be observed in Antarctica, New Zealand and Australia. However, during periods of intense geomagnetic activity, the auroral zones broaden and travel toward the equator. At these times people who live at lower latitudes, such as in the UK, may have a better chance of seeing the aurora too. 

Strong solar activity can affect the Earth magnetic field and result in spectacular displays of the northern and southern lights. As solar activity is expected to peak in 2024, we could be in for some beautiful skies this year.  

Why does the aurora happen?

The aurora we see dancing in the night sky is caused by activity on the Sun. The Sun is an enormous ball of super-hot ionised gas that continually emits a stream of charged particles, which is known as the solar wind. The solar wind isn’t always the same; its speed and strength can vary depending on solar activity driven by a variety of structures, such as coronal holes and active regions, that can be observed on the surface of the Sun. 

Coronal holes are temporary features that can form on the Sun. These are vast areas where the Sun magnetic field opens up, allowing the high-speed solar wind to stream out into the solar system. This fast solar wind can take around three days to reach us on Earth.  

Active regions on the Sun are areas of strong and complex magnetic fields. These areas appear as dark ‘sunspots’ on the solar surface and can produce explosive events such as solar flares and coronal mass ejections. Coronal mass ejections are huge fast-moving clouds of charged particles launched by the Sun. They may take one to three days to arrive at Earth.

If these solar ‘storms’ are directed towards the Earth, the solar wind will interact with the Earth magnetic field, which directs the solar wind particles toward the polar regions. These charged particles slam into the atoms in the Earth atmosphere and the energy released during these collisions is emitted as light, causing the glow of the aurora.  

The colours that appear depend on the mixture of gases in the atmosphere. Green aurorae result from interactions of solar particles with oxygen; however, at higher altitudes, collisions with oxygen produce red aurorae. Blue and purple shades are caused by collisions with nitrogen. 

What is the solar cycle? 

The Sun goes through an approximate eleven-year activity cycle, which is measured by the number of sunspots seen on the Sun. During solar minimum, few sunspots are counted and solar activity is usually low. During solar maximum, many sunspots are seen, increasing the frequency of solar storms. As we know, these solar storms can lead to geomagnetic disturbances on Earth. 

Solar cycles have been recorded since the eighteenth century. Back in 2020, a panel of scientists predicted that the current solar cycle (solar cycle 25) would be fairly weak, similar to the previous cycle. Solar activity was expected to peak around July 2025. In October 2023, the Space Weather Prediction Center of the USA National Oceanic and Atmospheric Administration . This forecast a quicker, stronger peak of activity with solar maximum expected between January and October 2024.   

This is why we expect 2024 to be a good year for aurora-spotting opportunities. 

Why is BGS interested in the aurora? 

Knowledge of the Earth geomagnetic field is necessary when using a compass to navigate. The location of Earth magnetic poles gradually shifts over time and scientists at BGS model these movements to predict . 

Strong and rapid variations in the Earth magnetic field due to solar storms can cause errors in the magnetic corrections required for navigation and induce electric currents in the ground, which can then travel into power lines, pipelines and railways. In the power grid, these can overload transformers, resulting in power outages. They can increase corrosion in pipelines and can disrupt railway signalling (as recently ).  

51ÁÔÆæ provides various space weather services to organisations such as the National Grid, the UK Met Office and the European Space Agency to monitor current geomagnetic conditions and forecast future geomagnetic activity. 

How can I see the northern lights in the UK? 

The likelihood of seeing the northern lights varies across the UK and depends on a number of factors, most importantly how is and how far north you are. Those in the north of Scotland may see the northern lights often with only minor geomagnetic disturbances. When activity gets more disturbed and the auroral zone moves southward, more of Scotland, Northern Ireland and the north of England have a chance of seeing it. It usually requires a rare and significantly large magnetic storm for the aurora to be seen widely across southern England and Wales. 

The aurora sits above cloud level, so you need to get lucky with the UK typically overcast weather as to spot the aurora. Head to a dark place away from light pollution; a full moon can also cause issues if the aurora is faint. Generally, look to the north, although during intense storms it could be overhead or elsewhere. Having a clear view to the northern horizon either from the coast or from an elevated position can be advantageous. 

Expectation vs reality

To get the best view of the aurora you will need a camera. Photographs of the aurora will often portray the aurora as much brighter than can be seen by the naked eye. Long-exposure photographs can take in more light, exposing the colours in the sky, whilst by eye a weak aurora may appear more monochrome and cloud-like. . 

often have night-mode photography options, which can take reasonable photos of the aurora without the need for expensive photographic equipment. Having a tripod to stabilise your camera or smartphone can help avoid vibration during long-exposure photographs.Ìý

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• 51ÁÔÆæ produces  
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• When there is significant geomagnetic storm predicted, we send out notifications to inform the public of the increased chance of seeing the aurora: or you can   

About the author

Three new underground geomagnetic observatories in County Fermanagh, Leicestershire and Sussex will detect and eventually help predict space weather, which can potentially disrupt power grids, satellite communications and the GPS on smartphones.

They were installed underground in quiet, rural locations by the BGS Geomagnetism team. The solar-powered observatories will collect data about Earth natural magnetic field and send it back to BGS in real-time, using the mobile phone network.

Why do we need new geomagnetic observatories?

Intense geomagnetic storms can have an adverse impact on technology like
power systems, satellite operations and smartphones.

The new magnetometers mean we now have full coverage of magnetic field change across the UK.

Very large geomagnetic storms produce widespread aurora. While beautiful, they have the potential to be incredibly disruptive.

They could cause power disruption and affect essential services like satellite communications and transport.

Now that we have monitors in our blind spots, we will better understand in detail where and what ground effects can occur and understand why they happened.

Dr Ciarán Beggan, BGS Geophysicist.

Britain has had geomagnetic observatories in Shetland, Eskdalemuir and
Devon since 1908, covering the country from north to south; the will improve the breadth of measurements from west to east.

Mitigating a national risk

Severe space weather was included in the UK Government .

Geomagnetic storms are one form of space weather. They interrupt essential
services by creating geoelectric fields in the subsurface, which then flow
into transformers, pipelines and railways, causing malfunctions.

Other effects include an increase in the density of the upper atmosphere (ionosphere), which disrupts radio waves passing through it. This leads to a loss of signal between the ground and satellites, affecting communications and the accuracy of global navigation satellite systems (GNSS). A huge number of technology systems rely on GNSS, including:

• phones
• trains
• self-driving vehicles
• timing for internet transactions

Major geomagnetic storms are relatively rare but, as Dr Beggan points out, they
have a pattern.

Major geomagnetic storms happen every 30 or 40 years in the UK, but we haven’t had a big one since 1989.

We live in a completely different society now, where we are all reliant on
continuous electricity supplies, smartphones and satellite communications — a major geomagnetic storm could significantly reduce those services.

We’re currently moving into a stronger part of the solar cycle, which means the chance of large geomagnetic storms is greater.

Geomagnetic storms are currently hard to predict in terms of size or even arrival time from the Sun. Adding the new sensors means we are able to measure their effects on the ground in real-time and advise on the impact onÌýtechnology.

Dr Ciarán Beggan, BGS Geophysicist.

Further reading

• Find out more about

Funding

The geomagnetic observatories were funded by UK Research and Innovation £20 million (SWIMMR) programme.