At http://phys.org/print365229743.html …. the fear of solar storms wrecking communication systems is troubling space scientists and almost every week the subject appears in articles and news flashes – or so it would seem. Probably my imagination but it is often broached by the journos on both ends of university press releases. A study in Nature Communications is saying they can be far bigger than previously imagined – and therefore destructive. Obviously, they have not been reading Bob Johnson or Rens van der Sluijs, otherwise they would be putting their hands over their ears.
A few years ago researchers found traces of a rapid increase of radioactive carbon (C14) in tree rings dated to 774/5 and 993/4AD. The cause has been open to debate, mainly between vectors such as a far away supernovae or a larger than normal solar storm (although the Earth passing through the coma of a comet was suggested by one piece of research). It seems mainstream has decided to plump for a solar storm, a super coronal mass ejection. Now, the same injection of C14 into the atmosphere has been discovered in Greenland ice cores of the same period (it does not say if it was an exact match). The researchers are convinced a solar storm was responsible so we can expect this will enter the literature and become a fact of science. It means that just over 1000 years ago we had two exceptionally large solar storms – but what did they do? Apparently, very little as nobody actually noted excessive auroral activity, or bothered to record it. This is very lax on the part of the Chinese as their court astronomers otherwise recorded all kinds of transient phenomena seen in the sky.