Solar Activity 

I was interested to note the recent BBC report that the Sun has unleashed its strongest flare in four years triggering warnings of Geomagnetic storms. This echoes the article by Dr Tony Phillips and Dr Madhulika Guhathakurta of NASA in our last issue (6:3). The article looked at critical infrastructure preparedness in the face of severe space weather as the Sun enters an active phase. Forecasters believe that a new solar maximum will arrive around 2013.



Coronal Mass Ejections (CMEs) can affect power grids, communication systems and satellites (affecting GPS navigation systems, for example) – all of which are vital components within our national infrastructure.

Emergency responders may also find themselves hamstrung by sudden loss of quality in radio communication. During solar storms, Earth’s upper atmosphere is disturbed strongly by X-rays and extreme ultraviolet photons from the Sun – and it all depends on the type of geomagnetic storm involved. Banking, finance and transportation systems could all be affected as well.

According to the North American Electric Reliability Corporation (NERC), when a strong geomagnetic storm is in the offing, utilities should:

• Postpone maintenance work and restore out-of-service lines to maximise the capacity of the grid;
• Maintain system voltages well within the acceptable range, because voltage swings may occur;
• Adjust the flows on high voltage lines to between 40 and 90 per cent of nominal rating; and
• Reduce the loading on any generators operating at full capacity, to provide reserve capacity and take other similar measures.

As the authors say, the basic strategy should be to: “Operate the system in a conservative mode so that it can handle sudden surges of current and voltages without overload.”

The International Living with a Star (ILWS) initiative has been established to learn more about the phenomenon, and to help forge international co-ordination and co-operation in this field. Check it out on www.ilwsonline.org

Emily Hough

The full article, Space weather: How vulnerable are we? Was published in November 2010 and can be found in Crisis Response Journal, Volume 6: Issue 3