UCL in the News: How new technology could save us from dangerous solar storms

Researchers in the UK are developing a deeper understanding of this solar activity, which centres on the Sun's own magnetic field, as Dr Sarah Matthews [UCL Mullard Space Science Laboratory] explains. …

"The Sun's magnetic field is in a state of constant flux. It is a bit like a bar-magnet that is rotating at varying speeds, and, as it rotates, it winds up the lines of magnetic field, and portions break through the surface." These manifest themselves as sunspots and are energetically unstable. When there is a high density of sunspots on the Sun's surface, there is a greater probability of the release of energy. This can result in a flaring of the surface of the Sun or, in some cases, the corona becoming detached and flung off at high speed. The greatest activity occurs roughly on an 11-year cycle, when there is a large increase in the number of sunspots. …

"The problem of these ejections hitting Earth is not a new phenomenon - the Sun has been doing this as long as it has been shining - but it is more important now because of the way we live has changed; we rely increasingly on satellite technology and power stations." Dr Matthews is working on ways to predict when such events might occur and whether they are likely to be significant or not. …

"In October and November 2003 and in January 2005 there were a number of active regions on the Sun's surface hurling these ejections every 10 to 14 days before going quiet again. At maximum activity it would not be unusual for maybe one coronal mass ejection to come towards the Earth every week, but these will not always have the correct magnetic field orientation to produce an effect. …

"I am involved with trying to understand how the flares and the coronal mass ejections are initiated and how they relate to one another," says Dr Matthews. "Sometimes we get one and not the other. I want to know what is the instability that causes this release of energy. Is there a unique set of conditions that will always lead to instability and can we predict when these events will occur by examining how the magnetic field of the Sun varies over time? If we knew that one of these events was coming we could put in place systems to mitigate against it - by putting a satellite into safe mode or preparing for the possibility of disruption to the electricity supply."…

Simon Hadlington, 'The Indpendent'