• Sun sneezes and…

    Living near a star has its benefits but one has to face consequences too. Last week we witnessed a M9 class solar flare and an intense Coronal Mass Ejection (CME) hitting the Earth. CMEs are large volumes of charged particles ejected from the Sun’s Corona. Interaction of these charged particles with the atmosphere gives rise to spectacular auroras which can now be found floating around on youtube.

    Solar Storm in the Earth’s atmosphere

    The strongest such event in recorded history the September 1-2 1859 Solar Flare also known as the Carrington event after the observer RC Carrington. Carrington was taking routine observations of sunspots when he came across this unusual event. The original report can be found here. As a result of this intense solar flare, the global telegraph network was disrupted. Charge flowing in the telegraph wire was large enough to have ignited telegraph paper.

    A recent example of a much smaller event was the solar flare of March 1989 which left 6 million people in Canada without electricity for several hours. If such an event were to happen now, power grids will be disrupted and intense radiation can knock off satellites. The two bedrocks of modern life will be damaged (depending on the magnitude of the event) and it is hard to imagine the consequences of living without electricity and satellites. Our civilization is more susceptible to natural disasters than ever. But, unlike in case of previous solar events, we now have a much better understanding of the physics behind these event and we can now predict such occurrences in advance.

    Other than the effects on technology, such events can have devastating effects on life. Charged particles blasted from the Sun ionize the Earth’s atmosphere which result in dissociation of nitrogen and oxygen in the atmosphere. A a result a multi step reaction in the stratosphere depletes the ozone layer. A depleted ozone layer gives way to harmful UV radiation which is well known to have carcinogenic effects. Such events could have affected life on our planet in the past. A detailed analysis by Brian Thomas and colleagues can be found here.

    But should be worry about it? Observations of Sun-like stars have shown much stronger flares than the Carrington flare. However, we don’t know what is the frequency of such events. It is probably very low but more research needs to be done in order to know for sure.


    • S. Domagal-Goldman

      My understanding is that our industrial capabilities (or lack thereof) makes the threat of a power grid failure even worse. I’ve heard we are less capable of replacing/repairing the power grid in the case of massive damages brought on by an extreme solar storm.

      You know anything about this Dimitra?

      • Dimitra

        One way is to remove the transformers from the grid temporarily when the storm is expected to arrive. This will result in a temporary blackout. But I am not sure how effective that will be.

    • David Grinspoon

      “Our civilization is more susceptible to natural disasters than ever.” In some ways yes, but in others, no. The Galveston hurricane of 1900, the greatest natural disaster in U.S. history, could never happen today in the same way. Back then there were no weather satellites and nobody knew it was coming…

    • S. Domagal-Goldman

      But then again, if we use hurricanes as an example, we have to acknowledge that greater overall population and continued migration to coastal areas means a hurricane of a given size will produce more total damage now than 10, 50, or 100 years ago. That doesn’t necessarily speak to susceptibility or resiliency, though.

    • S. Domagal-Goldman

      Dimitra, the question then becomes how long does it take to remove the transformers from the grid on a regional, continent-wide, or global scale? And how much warning to we receive that things are about to get bad? And is there a decision-making process in place?

      Interesting stuff to think about… An extreme solar flare event may be the biggest near-term natural disaster threat to our standard of living.

      • Dimitra

        Shawn, it can take hours to safely shut down the entire system. Regarding the warning, each solar event is different and our ability to predict such events is poor at this stage. Some types of events can be predicted in advance so that governments can get a chance to inform the public and do preparations, but this is not true for all events. In case of something unexpected, we will get warning from Satellites (before they are fried) and also from Earth-based cosmic ray detectors, because anything big happening on the sun shows up in our data. But this type of warning will give us 12-18 hours at best. Here is a good website to learn more about the response system in place: http://www.nswp.gov/nswp_index.htm

    • S. Domagal-Goldman

      Cool tidbit on this… the Mars Science Lab/Curiosity, the rover currently on its way to Mars, made measurements of the flare. Check it out:

      We only have a few hours of data downloaded from the RAD so far, but we clearly see the event, said RAD Principal Investigator Don Hassler, science program director in the Space Studies Department at Southwest Research Institute. “This SPE encounter is particularly exciting in light of the alignment between the Earth, MSL and Mars right now and for the next few months. It will be very interesting to compare the RAD data, collected from inside the capsule, with the data from other spacecraft.