“SC23 was about normal (e.g. see http://sidc.oma.be/html/wolfmms.html after a relatively strong 1980 and 1990. The current minimum seems to be ending, see for example http://www.wm7d.net/hamradio/solar/index.shtml where flux seems to (barely) bottom out in July.”
You’re looking at slight fluctuations that probably mean nothing statistically. The Sun is pretty complex. Look at the sunspot numbers reported throughout the Maunder Minimum for instance.
Not a single professional astronomer that I’m aware of has declared Cycle 23 over. The historical criteria for that is more Cycle 24 spots on the Sun than Cycle 23 spots at a given time, which hasn’t happened yet. Please cite any data you have that states otherwise.
Here’s a fairly recent NASA article on the subject:
http://science.nasa.gov/headlines/y2008/11jul_solarcycleupdate.htm
This astronomer seems to be ‘cheering’ for a relatively early Cycle 24, I believe due to earlier predictions he made. Note that he says we’re in the “first standard deviation” for the cycle length. It’s a roughly 69% probability (for a normally distributed variable) for that to be the case. However, we’re now only four months away from making it into the second standard deviation, which will go another 14 months. So, if the current solar minimum continues for about another 18 months, we will have exceeded the second standard deviation, which (again with a normal distribution) only happens 5% of the time (95% of the time a sample will fall within two standard deviations of the mean). That would start to look extremely significant.
Regardless, though, according to one of the leading theories of solar physics (the ‘solar dynamo’ theory) the already long, weak Cycle 23 means an even longer, weaker Cycle 24...which as far as I can tell means significant cooling for 12-15 years at least.
One last data point: in contrast to NOAA and ‘big science’, which continue to predict warm temperatures in line with CAGW dogma, the Farmer’s Almanac is predicting a cold winter:
http://www.freerepublic.com/focus/f-news/2065287/posts
I’m going with the Almanac. ;-)
That's rather difficult when there are no spots. It's not unusual to have no spots on the trough, so the only way to know is to extend the sunspot counts forward and backward (i.e. you know it was a trough after you have been through it). But there's another way which is to look at solar flux. Solar flux (at various frequencies measured by Hams and others) is at a minimum at the solar cycle minimum. But as you say there are slight fluctuations that could mean nothing. But my opinion is that the trough was in July and I have no evidence against that yet (and not a lot for it except for the tiny uptick so far in August).
It's all tied to the solar 'conveyor belt' that is mid-equitorial sub-surface plasma currents which drive sunspot creation and magnetic storming. The southern, and to a lesser extent, northern currents have slowed to speeds never seen before.
It'll be "a cold winter" and "colder than last year" for many years into the future.
SC23 was very strong - and very slow to “stop”, coming after a 21 and 22 very strong cycles.
I agree, that NASA solar specialist has been “cheering” for a strong, very-very-very fast-rising cycle 24 for a long time.
So far, he has been very,very disappointed, hasn't he?
March 2007 (and some had predicted solar cycle 24 starting even earlier than that! ) was its original “start date” and here we are in mid-August of 2008, with still NO sunspots in sight at all.
My prediction?
Winter 2008-2009 is looking to be another cold one. Temperatures between (now) and the START of solar cycle 24 are going to be very cold - certainly colder than any since the 1980’s - then they will increase a little bit as the 11+ year cycle of solar cycle 24 increases to its maximum. (Originally, solar cycle 24 was to have peaked in 2011 - that WON'T happen, but the peak will come a few years later.) So, about 2013-2016, temperatures will max out, then decline again through the solar cycle 24-solar cycle 25 “minimum (which can't get any l;lower than today's “zero” sunspots - but the solar flux might go down some more!) then rise again a little to the expected “low peak” of solar cycle 25.
So we will have a few very low peaks and even lower valleys (or a complete Maunder Minimum Mini-Ice Age) between now ans 2035.
Now, after 2030? We "might" start heating up again after 2030 - IF (big IF) the AGW extremists are right.
Then again, at about 2035, we are due for the next 70-year solar warming period to begin again, aren't we?