Thursday, November 20, 2014

Large sunspot is again within sight-line of Earth, meaning that technology and Internet disruptions from solar coronal mass ejections (if Carrington-like) are possible.


Brian Van de Graaff of WJLA in Washington DC interviews Dr. Alex Young of NASA about the huge sunspot that is reappearing in the Sun’s rotation.

  
Relatively few television stations have covered this concern much in the past two days.
  
The sunspot threw off several large solar flares in October but no damaging coronal mass ejections.  Not all flares cause CME’s, and the most intense part of a CME is likely to miss the Earth unless the Earth is right in front of the location of the CME’s path.  A flare can cause some satellite and radio disruptions in eight minutes;  a CME typically takes about 2-3 days to reach Earth, and with current technology, the severity of it isn’t known until about an hour before it arrives.
         
The largest CME’s can cause severe damage to power grids, which in the worst cases could take months or years to repair.  One problem is that we don’t make many transformers within the US.  For a really large flare, damage to the grid could be mitigated by deliberate brownouts or blackouts, and by adding extra capacity and improving the grounding of transformers with newer technology, which isn’t discussed often but which business interruption insurance companies follow and say is progressing.

The sunspot is somewhat smaller than it was in October. 

A big practical concern, in the case of a damaging CME incident, would be how the Internet would be affected by brownouts, or whether less “essential” services, like social media or publishing platforms, would be shut down for some time. 

The largest CME in recorded history was the Carrington Event of 1859, which disrupted telegraph service just getting going at the time.  That could be catastrophic today, as we have become dependent on technology without securing it against rare events.  There was a large incident in 1928, and another in 1989 that disrupted power in Quebec. We may have missed a big CME by a few days (having moved out of line for a direct hit just in time) in July 2012.  
  
Power disruptions are more likely at polar latitudes, and at this time of year might be more affected in the southern hemisphere.  

Wikipedia attribution link for CME illustration. 

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