1,000,000 degrees with a chance of solar flares: a Pint of Science solar weather report

Solar flare. Image provided by Author. Credit: NASA

 

Mendeley is proud to be partnering with Pint of Science for the third year running.

 

As an introduction to the great talks on offer we’re going to be previewing some of the most interesting here on the Mendeley Blog, featuring speakers from across all Pint of Science themes. You can follow along on our blog under the tag PintofScience17 or on Twitter under the hashtag #pint17.

Matthew Allcock

Matthew Allcock is previewing his talk/weather report “1,000,000 degrees with a chance of solar flares,” which you can attend on 17 May The Holt Cafe in Sheffield

Matthew (@matthew_allcock) is a PhD Student in the School of Mathematics and Statistics at the University of Sheffield. You can follow his work on Mendeley or on his personal website.

 

 

What is the biggest threat to the UK? The UK has a continually updated list of events that pose a catastrophic risk to our society, which includes events such as major terror attacks and flooding due to climate change. High on this list is severe space weather.

Why do such solar weather events occur?

Space weather encompasses the effects that charged particles ejected from the Sun have on the Earth. From satellite malfunction to large-scale power shortages, the volatile Sun poses a significant threat to modern society. The Sun waxes and wanes through a cycle of fluctuating activity with a period of approximately 11 years. During ‘solar maximum’, magnetic activity on the Sun is at its most violent. Tubes of plasma the size of the Moon, shaped by the Sun’s intense magnetic field, rise from the deep solar interior and penetrate the surface. Where these tubes break the surface, we see what are known as sunspots: near-circular dark regions that can be many times the size of Earth.

These magnetic tubes can also dramatically elevate tonnes of hot plasma from the bubbling surface to the high solar atmosphere, known as the corona, and remain in a semi-stable state. Energy stored in the magnetic field near the Sun’s surface builds up as these magnetic tubes are buffeted from below by convection currents until this energy can be stored no longer and is released as an ultra-bright solar flare. This blast can destabilise the elevated plasma, dynamically releasing it as a stream of charged particles, known as a coronal mass ejection (CME), into interplanetary space.

Are we prepared for the next major solar event?

The mid 1800s saw an anomalously active period for the Sun. In September 1859, amateur astronomer Richard Carrington was completing his daily observations of the solar surface when he noticed a blurry brightening around a sunspot. This was the first observation confirming the existence of solar flares and is the largest solar flare in recorded history. It triggered a huge CME that headed straight for Earth. In the hours following this sighting, a huge geomagnetic storm was detected and people witnessed the northern lights phenomenon as far south as Colombia.

What would be the impact of a Carrington Event today? Satellites rely on a complex system of intricate electronics. If a CME hits a satellite, induced electrical currents can cause short-circuits that can disrupt the operation of the satellite. A large CME hitting Earth induces ground-based electrical currents which can short-circuit power stations and cause blackouts and damage to electrical transformers. Had the Carrington Event occurred today, the financial impact of the predicted large-scale blackout is estimated to be upwards of £1 trillion. Blasts from solar flares and CMEs cause waves to propagate along the surface and in the atmosphere of the Sun.

In my research, I use these waves to probe solar structures and understand what makes them erupt by combining mathematical models of magnetic structures with the latest solar observations. It is all incredibly difficult to forecast.

 

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