Frequently Asked Questions on Solar Activity and 2012
- How likely are we to have a catastrophic solar storm in the next 5 year?
Not very likely. Solar activity follows an 11/22 year cycle (see below). We are now in a phase
of increasing solar activity. However, the solar activity, which is measured by the solar sunspot number,
is just ordinary. Daily sunspot numbers can be found on
and plots of historical sunspot numbers can be found on
Windows to the Universe - Sunspots
Current sunspot numbers run at about 80-120, but historically they have been as high as 250.
Furthermore, the last solar minimum was unusually long and deep, with long stretches of no sunspots
at all. That had some poeple to believe the sun may become more quiet for decades, maybe even
leading to a new Maunder minimum (
At present, the consensus prediction is a maximum that is lower than normal (
site). Note that the sunspot number (SSN) is not a simple count of sunspots. Larger sunspot areas count
as more than one spot.
- Would a solar storm the size of the 1859 one knock out power to the whole country, or just certain areas?
At worst, such a storm would knock out some or many of the 750 kV transformers that are
essential for the backbone of the power grid. Local power generation would be largely unaffected.
Since some regions depend more on power imported from long distances, and are thus more dependent
on the backbone transmission lines, the effects would be uneven. No region would be without power
because there is always some local power generation capacity that does not depend on the powergrid backbone,
but availability would vary and 'brownouts' would be common.
- How long would the power be out for?
It could take months to relace 750 kV transformers since they are custom produced, very expensive,
and only few companies can produce them. A
study by the National Academy
provides more detail on this.
- Is there anything we can do to prevent power outages from solar storms, and do we have a plan?
There is nothing one can do to prevent the storms from happening, much like tornadoes or hurricanes.
However, precise prediction of solar storms allows power grid operators to reduce line loads. to
re-schedule maintenance, or even shut down some lines entirely. However, just as with tornadoes and hurricanes,
prediction is a tricky business. At present, the NOAA
Space Weather Prediction Center
is in charge of predicting
geomagnetic storms. Because the science behind predicting solar storms is still in its infancy
National Space Weather Program
coordinates research efforts to better understand the science of space weather, such as
NASA's Living With a Star program
and several programs
at the National Science Foundation (NSF) such as
- Would a solar storm cause all the nuclear plants to meltdown?
If so, how long would that take to happen?
Extremely unlikely. Although (ironically) nuclear plants need power for cooling even after they are
shut off, they have numerous backup systems to provide power if they can't get any from the powergrid.
The meltdowns in Fukushima happened because all backup systems (diesel generators and batteries)
were destroyed by the earthquake and tsunamis. A solar storm would not have such an effect.
- Is it true that there is a big hole in the magnetosphere that will let in more solar storms?
Yes, there is sort of a hole in the magnetosphere under certain conditions. This was a somewhat
surprising finding by co-workers of mine and myself. We presented these results at a press conference
at the 2008 Fall meeting of the American Geophysical Union in San Francisco, which was
also publicised as a
NASA press release
. This study mainly addressed the question as to how plasma from the solar wind enters the magnetosphere.
Although the study was also published in scientific journals (see P058 and P060 on
my web page
) the press release simplified our conclusions to make them better understandable to non-scientists.
Unfortunately that message did not always come across as intended. We had found a process that
had always been there but only been detected for the first time, however, often this was depicted
as something that was new and would have immediate implications in the future. We mentioned in our
publications and press conference that the intensity of storms could be affected, but did not
quantify the effect. Apparently, some people assumed that the effect may be dramatic. However, there is no reason
to believe this is so. In fact, there have been a few studies that predict that storms can
be stronger by 5-10%. This would not be anything to worry about. Also, the effect would occur
every other solar cycle, that is every 22 years. Unfortunately we do not have enough data that go
back a few solar cycles to produce reliable statistics. However, there is nothing in available
data to show any dramatic effect.
Many doomsday websites and books have combined these findings with the purported end
of the Mayan calendar (there are, in fact, several Mayan calendars, and only one ends on 12/21/2012.
There is no evidence that the Mayans attributed any significance to this end date. It is just as arbitrary
as 1/1/2000) to come up with the idea that the world as we know it would end on that day by the
intrusion of large amounts of plasma from a solar storm into the magnetosphere. There is not a shred
of evidence for this scenario even being of remote likelyhood.
It is just pure nonsense, which, however, seems to be generating a good chunk
of money for those who write about it.
- Is it true that the sun has not only 11 year cycles but 22 year cycles that make it even stronger?
If one only looks at the sunspot number the cycle has a period of 10-13 years, with 11 years being
the median length. However, sunspots are a magnetic phenomenon (the solar magnetic field within the sunspots is much
stronger than in the surrounding areas). For the past 80 years or so we can also measure this
magnetic field, and it turns out that it switches its polarity from cycle to cycle. Thus the cycle
has both 11y and 22y periodicty. However, there is no indication that the strength of a cycle depends on
polarity, which can also seen in the
plots, where the even numbered cycles have one polarity and the odd numbered ones the other polarity.
- Is the sun really being quieter than usual?
Not really. The last solar minumum was unusually long. However, current sunspot numbers are well
within a normal range.
- How strong is this solar cycle supposed to be?
Some predictions call for a weak solar cycle 24 (that is the cycle number that we just enter. The numbering
started in 1750, although sunspots have been observed sine ~1600) with a peak around 100. However, recently
higher values have been observed, so cycle 24 may just be an ordinary one with a maximum of ~150.
- Most importantly, do you think jt would be the end of the world if this happened?
Absolutely not. There are only three ways that I can see to end mankind:
A) A global thermonuclear war. The ensuing
would likely not be survived by many, if any humans.
impact of a large asteroid.
May happen every 10-100 million years or so. We should be pretty safe for now.
Also, we would see it coming for quite some time.
(exploding star) in our stellar neighborhood. That is also a very unlikely event that
may only occur once every 100 million years or so.