On Saint Patrick's Day (17 March) the northern lights danced a lively green jig across the skies of Ireland and Britain. The source of these magnetic storms was not just one but two huge eruptions of electrically charged material from the Sun, which travelled through space at millions of kilometres an hour, colliding with the Earth's magnetic field.
The resulting geomagnetic storms -- the strongest for a decade -- led to dramatic displays of the northern lights and induced significant additional currents in the power grids of Britain and Ireland. Despite that, neither grid suffered any damage, boosting the prospects for resilience when worse 'space weather' events take place.
Two research groups, led by Peter Gallagher of Trinity College Dublin and Gemma Kelly of the British Geological Survey (BGS), will this week (7 and 8 July) give presentations on the effects of the storm this week at the National Astronomy Meeting in Llandudno, Wales.
As far back as 1852, Dublin-born Sir Edward Sabine showed that magnetic storms waxed and waned with the number of spots on the Sun. Not long after this, in 1859, Richard Carrington observed a huge solar flare that was followed within a day by brilliant displays of the northern lights in regions as far south as Italy and Cuba.
In addition to brilliant auroral displays, the electric telegraph - the Victorian internet -- was found to be disrupted during periods with large geomagnetic storms. The Daily News of September 1859 reported, "the electric telegraph was disrupted … owing to some mysterious atmospheric influence."
Nowadays, society has become vastly more dependent on technological systems for communications and electricity. These too can be disturbed by magnetic storms -- navigation systems can have positioning errors, radio transmission can be blacked out, and power grids can become unstable. The most infamous impact occurred in 1989 in Canada, when a magnetic storm interrupted electrical power for more than six million people for nine hours at a cost of over C$13 billion (£6.6 billion, 9.3 billion Euros).
For this reason scientists at Trinity College Dublin and at the British Geological Survey were on high alert this Saint Patrick's Day. "A warning message from our magnetometer network developed by Trinity and the Dublin Institute for Advanced Studies notified me of the onset of a large geomagnetic storm as I watched the Saint Patrick's Day parade with my family," according to Professor Peter Gallagher, head of solar physics and space weather at Trinity. "That evening, the sky danced red, pink and notably green across Ireland and the UK."
The scientists' attention immediately turned to potential effects on communications and electrical power systems. "My research student Sean Blake quickly ran the British Geological Survey's magnetic storm model to see if there were any threats to the Irish power grid," said Gallagher. "Despite the storm's size, no significant effects were predicted or indeed reported."
Dr Kelly added: "This storm and a more recent one in June were the biggest we have seen in over 10 years. They produced the biggest electrical fields on the ground - and hence currents - we have seen since our system started operation in 2012. Fortunately, the British power grid held up well too, so it gives us more confidence that at least some of our systems are pretty resilient to inclement space weather."
The Saint Patrick's Day storm has enabled the Trinity team to demonstrate that their alert system works in Ireland and helped BGS scientists gather data on how the storms affected Britain. Blake concludes, "We can now monitor and model magnetic storms in near-real time, which not only allows us to understand the physics of such phenomena, but also to provide a valuable service for power operators."
Cite This Page: