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Eadfrith
2012-Oct-07, 07:01 PM
Has it happened already or did it all fizzle out? :confused:

George
2012-Oct-07, 07:17 PM
Has it happened already or did it all fizzle out? :confused: 2013 (http://www.swpc.noaa.gov/SolarCycle/) seems to be the likely year of the maximum. Yet, it looks like it will be a weak maximum, but I won't say a minimum maximum.

tusenfem
2012-Oct-07, 08:08 PM
Yes, the solar activity is still increasing, but it is not at as high a level as the previous one. I have a plot of the activity at work, which I will try to post tomorrow
Indeed in observations near Venus with the Venus Express magnetometer we see a clear difference between 2006 and 2011 in certain wave activity, which is directly related to solar activity.

tusenfem
2012-Oct-08, 09:18 AM
As promised, the sunspot graph up until September 2012.

Eadfrith
2012-Oct-08, 11:55 AM
wow.... that is really down, even lower than predicted.

Interesting double peak during the last solar maximum too.

John Jaksich
2012-Oct-08, 11:36 PM
As promised, the sunspot graph up until September 2012.As I have heard it said: we don't really know what normal is for sure. Given all of other Suns in the Galaxy that may be similar to our Sun--the Solar cycle might be anomalous for our Solar System.

George
2012-Oct-09, 12:36 AM
As promised, the sunspot graph up until September 2012.
My link was to the same graph. I wonder if links should be made to stand out a little better?

Tensor
2012-Oct-09, 01:08 AM
Here is comparison for several different cycles



http://www.solen.info/solar/cyclcomp2.gif



One thing that is interesting is a comparison of Cycle 24 with Cycles 12 and 16. Both of those cycles hit a peak (cycle 12 at 35, cycle 16 at 39 months) into the cycle (about where 24 is now(38 months)). Then there was a decline until the 47th month (cycle 12) and 51st (cycle 16) when they both climbed to the cycle high. If Cycle 24 follows this pattern, then about the 50th month of this cycle, October 2013 the smoothed number should start climbing. One thing to remember is that the smoothed number lags the current months by six months. So the to get the smoothed number to start climbing in October of next year, to follow the pattern, the actual numbers should start climbing sometime next summer. Of course, this cycle could be more like cycle 14 and may have already hit it's peak. Even so, this year (cycle) is still greater than or within 5% of seven of the cycles in the past 300 years.

For an indication of the drop for this year (cycle), I offer this comparison of the this cycle with the last three:

http://www.solen.info/solar/cyclcomp1.gif


The two above graphs are from the Solar Terrestrial Activity Report, prepared by Jan Alvestad.

ShinAce
2012-Oct-09, 01:18 AM
A picture is worth a thousand words.

Thanks tusenfem and Tensor! Cool stuff.

Ivan Viehoff
2012-Oct-09, 09:21 AM
Yes, the solar activity is still increasing...
What leads you to say that? It certainly isn't obvious from the graph you present, though who can know whether it will wiggle up and down now, it has in other cycles. I thought I read some stuff recently that suggested perhaps we had already had a maximum, though it is always hard to know. I think it was based upon which hemisphere of the sun the sunspots were predominantly on. I believe there is some precedent for shorter cycles in the past.

tusenfem
2012-Oct-09, 12:52 PM
Well, I cannot be certain, true, we will have to wait till later times so see whether the counts go up or down.
And yes, the solar cycle (half of it actually) is only on average 11 years, but can vary from 8 to 13 years.

Tensor
2012-Oct-09, 03:43 PM
I thought I read some stuff recently that suggested perhaps we had already had a maximum, though it is always hard to know.

That has been due mostly to the persistent reports that the northern polarity has changed (going back to last year). While it has crossed, (there are positive and negative values, this cycle, the northern polarity is negative) into the positive, it has gone back to the negative. Previous cycles indicate that it can cross up to six times before the change actually occurs. The southern polarity has not crossed at all this cycle. Again, previous cycles show up to a year between polarity changes. One thing about this cycle has been the polarity values have been lower this cycle than previously.


I think it was based upon which hemisphere of the sun the sunspots were predominantly on.

There really isn't any hard and fast data on which hemishpere indicates a maximum. From 1950 to 1972 there were a total of about only 2 and a half years where the southern sunspots were greater than the northern. That time included two rises and one fall. There was 2 years of more southern during the first rise, and a half a year during the second peak. The entire fall was northern excess. The next three declines had a large excess of southern sunspots (but not exclusively) and the rises were a mixture of south and north.


I believe there is some precedent for shorter cycles in the past.

As tusenfem noted, the cycles aren't strictly on a 11 year cycle.

PlutonianEmpire
2012-Oct-11, 02:38 AM
Seeing those graphs remind me of an article I saw quite a few months ago where they were reviewing all the photographic plates of the stars dating back about a century ago or so and discovering miniscule, very-long-term variations in brightness or other sort of activities; could the difference between solar cycles in our own sun be similar to that in any way?

Eadfrith
2012-Nov-06, 08:23 AM
Well, according to spaceweather.com, solar maximum has been and gone :doh:

http://www.swpc.noaa.gov/SolarCycle/index.html

Jens
2012-Nov-06, 08:59 AM
Well, according to spaceweather.com, solar maximum has been and gone :doh:


That's not what the link says. It says the minimum occurred in 2008, and was a prediction that the next maximum would be in 2013. Or am I looking at a different link than you intended?

Eadfrith
2012-Nov-06, 01:33 PM
Yes its on the spaceweather.com homepage for the 6th of November.

Swift
2012-Nov-06, 02:17 PM
Yes its on the spaceweather.com homepage for the 6th of November.
Here is what it says on spaceweather.com

Forecasters have long expected the Solar Max of 2013 to be the weakest of the Space Age. It might be even weaker than they thought. As shown in this 20-year plot of sunspot counts vs. time, the sun is underperforming:

Sunspot numbers are notoriously variable, so the actual counts could rapidly rise to meet or exceed the predicted curve. For now, however, the face of the sun is devoid of large sunspots, and there have been no strong flares in more than a week. The threshold of Solar Max looks a lot like Solar Min. NOAA forecasters estimate no more than a 1% chance of X-class solar flares in the next 24 hours.

I think it much too early to make predictions and we'll have a much better idea in the next 6 months or so.

Tensor
2012-Nov-06, 04:35 PM
I think it much too early to make predictions and we'll have a much better idea in the next 6 months or so.

That is just about right. Go back up to post #8 and look where we are in cycle #24 and compare that to Cycles #12 and #16 (and remember, we're six months farther along as the smoothed sunspot number lags by six months). Those hit a low peak, then declined until an increase to the actual peak for the cycle. And note that cycle 24 is higher than cycle 12, at the same point in their cycles. If Cycle #24 is going to make that climb to a higher peak, that climb should start in about six months ( again, remember the six month lag in the smoothed number). Of course, we could end up with a cycle #14, just with a high smoothed number. It's also interesting to compare the cycle following these:

Cycle 12 75 Cycle 13 88
Cycle 14 65 Cycle 15 108
Cycle 16 78 Cycle 17 120
Cycle 24 67*

*Current high of Cycle 24.

It's also possible that Cycle 24 has hit it's peak, but, as Swift says, we still have to wait a few more months.

Eadfrith
2012-Dec-29, 06:46 PM
Another article on spaceweather.com - 29th Dec on the very low solar maximum. Looking at the latest sunspot graph, the maximum occurred earlier in 2012.

http://www.swpc.noaa.gov/SolarCycle/index.html