If you have an interest in astronomy, or follow those "end of the world" blogs, you've probably heard about solar flares, and the potential impact of extreme events on the earth. Solar flares are associated with sunspots, are a regular feature of the Sun, and are normally not something to be worried about. However, due to solar cycles, about every 11 years or so there is a period of increased sunspot activity which can result in flares which actually have an impact on the earth. Recently we have heard stories of potential doom, including worldwide power outages and GPS satellites being knocked out. The next solar maximum will be about 2025. Should we be worried?
Well, yes and no. Most of the concern revolves around the potential for a very strong solar flare which could potentially overload transformers and cause widespread, and possibly permanent power outages. This is a real threat, and was described recently in a National Academy Of Sciences report. In particular, a repeat of a very large flare which occurred in 1859 (known as the Carrington Event) could, according to the report, cause an electromagnetic overload of power grids, cause transformers to explode, with damage that might not be repairable for 5-10 years. Now, the Carrington Event appears to be quite unusual, and most solar events are much less spectacular. But it should be on our preparation radar. Smaller scale events can still cause regional outages (such as in 1989, when a solar flare resulted in a widespread outage in Quebec, lasting 12 hours and affecting 5 million people)
Fortunately, we have some wonderful resources available, especially from the NOAA Space Weather Prediction Center which, like its terrestrial counterpart, offers warnings of activity that could cause problems. However, to be able to use these warnings and resources, we need a quick lesson in solar flares. Here is the super-quick version: for a more detailed account see the SWPC FAQ. Basically, sunspots can result in solar flares which are intense bursts of electromagnetic radiation. These only really affect the earth if the sunspot is pointing right in our direction. The most immediate impact of these earthbound flares is a very quick increase in X-ray flux. You can see current X-ray flux values in this plot from the NOAA GOES satellite (also available on the SWPC site):
Anything over "4" is classed as a storm, although it's really 8's and 9's which spell trouble. Again for a mapping to real effects, see the G-scale on the NOAA Space Weather Scale.
Adapted from an article originally published in allhazards.blogspot.com
Some of you might be familiar with the AllHazards Blog where we have been posting for many years about breaking events, informatics in disasters and emergency response; and new perspectives on preparing for small and big emergencies and disaster. We will be migrating the blog to this site, so that everything is in one place. We will start by re-posting some of the most popular entries from the AllHazards Blog.
We will no longer post the regular TAB release as an "update" since these are routine.
The May 8th threat analysis briefing is now available in the Member's Area of the site.
The May 1st threat analysis briefing is now available in the Member's Area of the site.
The April 24th threat analysis briefing is now available in the Member's Area of the site.
The April 17th threat analysis briefing is now available in the Member's Area of the site.
The April 10th threat analysis briefing is now available in the Member's Area of the site.
The April 3rd threat analysis briefing is now available in the Member's Area of the site.