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Solar Cycle 24 Nears Peak

July 29, 2013; 6:36 AM ET

We are currently near the peak of Solar Cycle 24, according to the ISES Solar Cycle Sunspot Number Progression. See the graph below:

Data Observed Through This Past April

Compare this to what was predicted by NASA:

Notice that the peak of solar cycle 24, which we are currently in, is nowhere near the peak of solar cycle 23. Then, compare that to what was predicted. According to NASA, cycle 24 should of been at least as busy, if not busier than cycle 23.

So, the question is: with NASA's prediction that the peak of solar cycle 25 is even lower, do we believe it?

Was it so wrong about solar cycle 24 that we throw out the prediction? Or do we believe the trend that it will go down?

And, more importantly, what does it mean?

Well, let's assume that the next peak will be as quiet or even quieter than this cycle. If that happens, we may expect:

1) Less of the following: sunspots, solar flares, coronal mass ejections (CMEs).

2) Times of low solar activity seem to correspond loosely with times of cool weather. For example, during the 70-year period from 1645 to 1715, few sunspots were observed, even during expected solar cycle peaks. Western Europe entered a climate period known as the "Maunder Minimum" or "Little Ice Age." Temperatures dropped by 1.8 to 2.7 degrees Fahrenheit.

On the other hand, times of increased solar activity have corresponded with global warning. During the 12th and 13th centuries, the Sun was active, and the European climate was quite mild.

A look at the solar cycle over the last 400 years or so. The red arrow indicates the year 1928, which scientists expected this peak to be close to. In actuality, it failed to live up to expectations.

3. Most scientists expect solar cycle 25 to be quiet, as we mentioned above. This may lead to a global cooling pattern over the next few decades. If this cooling does take place, it may counteract any warming caused by increasing greenhouse gas concentrations. This may cause a "lull" in the general warming that this planet has experienced recently. Far in future, if the solar cycle becomes busy, it may lead to a rapid warming period.

Another wild card is that some scientists are thinking this current solar cycle may see a secondary peak early in 2014. Notice, in the second graph above, the recent trend was that there was a second peak (cycle # 20, 21, 22 and 23) while cycles #18 and #19 did not. The thinking is that #18 and #19 were strong, while the others were not. The fact that this solar cycle is weak plays a role into the thinking that a second peak is possible.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or


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Astronomy Blog
The astronomy blog, by Dave Samuhel, discusses stargazing, including how weather will affect viewing conditions of astronomical phenomenon.