Australian Space Weather Agency Revises Solar Cycle 24 Start, Adding 6 Months

Lief,
That’s an unexpected answer. Thanks.

Lief,
And the amount of solar ultra-violet light from the sun correlates with the solar cycle? Last question for the day, I promise.

“But” = “Bad” I quit for the day!

Gary Gulrud:
Including the albedo, UV associated with solar flaring, and solarwind/geomagnetic fluctuations the energy absorbed by the earth varies >10% (my WAG).
I meant to comment on this in the previous “400 spotless days” thread.
How does this relate to the -0.063 degrC/decade decline in TSI since circa 1992? http://www.skepticalscience.com/images/tsi_vs_temp.gif . Leif (after Lean) posits that the TSI data prior to circa 1980 are too low in that graph, but if I am to take the data of the past 20 years as well-supported, then it seems reasonable to cite the downward trend. Coupled with the oft-claimed aerosol albedo increase of -0.07 degrC/decade I derive a -0.133 degrC/decade effect.
Since many data are showing a slight cooling of the seas and air, and the solar & aerosol albedo offsets seem reasonable, then seems to me the AGW signal is a slightly less inverse signed value.
Note, however, the level of cooling claimed to be imparted by aerosol albedo is under assault: http://www.jpost.com/servlet/Satellite?cid=1218710365643&pagename=JPost%2FJPArticle%2FPrinter
( clouds of dirty aerosol pollutants saturate into a net heating effect faster than previously thought. Surface aerosols heat up more on a cloudless day )

Leif, Gary…
Forgive the terse replies, I’m on the road… I’ve had to work on the tie end rods on our car today. RV Parks are not the best place to do that kind of work.
Leif, the owner of the graph @ur momisugly skepticalscience.com cites a -0.1 degrC trend since the early 1990’s. I don’t know if he managed to scale the TSI to match w/m-2 to Celsius. I’ve read the cite elsewhere, however, of the -0.1 degrC (roughly -0.3 w/m-2) decline.
As for contemporary TSI accuracy, I thought the modern solar measurement era (for consistency purposes) was circa 1980 & assumed such in prior discussions. Shifting that back to 1945 doesn’t necessarily help the AGW argument, not sure what it does to the skeptic argument either.
IAC, what I”m driving at is the average reduction in TSI since 1992. If that interpretation is valid then I’m not ready to dismiss TSI’s contemporary effect. How all the manifold effects (from magnetic interactions, space borne dust, UV interactions & aerosol albedo) compound seems very much up in the air (and to a unstudied lad like myself I surmise it’s still a young field).
Still, with heliomagnetic models projecting a fall-off for SC#24 & Hathaway’s conveyor model predicting a fall-off for SC#25, I see a big trend evolving. Which model is most predictive seems less material to Earthly concerns than the unanticipated change in climate trend that seems strangely contemporary with the changes in the sun & increases in Earth’s albedo.
It comes down to isolating the GHG signal. If drop in solar ouput & increase in albedo from aerosols & GCR-spawned cloud cover is offsetting the AGW signal, and temperatures are holding steady, then it seems to directly address the climate sensitivity quandary in terms of putting the “crisis” into perspective: 0.135 degrees Celsius/decade.
This, as opposed to the wildly alarmist cant of Oliver Tickell, ominously claiming inevitable human extinction due to 4 degrC AGW:
http://www.guardian.co.uk/commentisfree/2008/aug/11/climatechange
Bjorn Lomborg was invited to respond and he lambasted Tickell:
http://www.guardian.co.uk/commentisfree/2008/aug/15/carbonemissions.climatechange
And Tickell’s rejoinder: http://www.guardian.co.uk/commentisfree/2008/aug/21/climatechange.scienceofclimatechange
Note how Tickell avoids all of Lomborg’s salient points of phased climate plateaus and societal response. Seem to me the evidence against Tickell’s alarmist ilk is staring everyone right in the face. Tickell’s argument, in fact, is counterproductive b/c it invites despair and apathy, so the tactic seems asinine.
I agree with Gary there’s much left to be learned and considered but I see the trend data and analyses we have (TSI, aerosol albedo, soot, surface ozone, etc.) as possessing sufficient weight as to help policy makers better evaluate the risk and embark on phased – not hasty – measures that’ll steer society into a risk-managed, cost-effective critical path.

Leif,
I think I asked you this question before but I got no answer. I asked two other physicists; one did not answer and the other said it was a good question but impractical to implement. The question is this:
Why not measure (by satellite) the incident energy upon the earth and subtract from it the reflected and radiated energy from the earth (also measured by satellite). The difference should give us the long term temperature trend of the earth, right?
Al Gore’s satellite (Triana) is fitted with a radiometer but has not been launched. It seems it might do the trick if launched.
I suppose this is an old question but I have not yet heard a satisfactory answer.

Dr. Hathaway’s most recent prediction (June 2008) has done a better job of tracking with this minimum than the earlier ones, but even this one could be reaching a “tipping point” of sorts. Through June, the central prediction line had actually trended below the SIDC mean values, but July fell below it, and at this point it seems August will do the same.

In looking at the latest plot, what struck me was the long gradual fall of Cycle 23 that abruptly turns to the steep rise leading to the Cycle 24 maximum in January 2012. It does look a bit…forced, and begs the question of what has been typical historically for the change in slope from a longer cycle’s fall to the next cycle’s rise.
According to the Marshall website, the predicted values are for “smoothed” International Sunspot Numbers (i.e. from SIDC). If I understand the criteria for officially measuring cycle lengths correctly, then Cycle 24 would begin where these values reach a minimum, which looks like a value of 2.1 in May 2008. This would close out our beloved Cycle 23 at 144 months (making it the 5th longest ever, BTW). Cycle 24 would then have a rise length of 44 months, reaching a smoothed maximum of 135 in January 2012.

Comparing Cycle 24 to other cycles in the plot of SSN Maximum vs Cycle Rise Time (I believe first credited to Waldmeier in the 1930’s?), and cripes! It’s almost exactly on the linear trend-line…a textbook case! So the amount of rise over the length of the rise isn’t abnormal at all. But the curve still looks a bit odd. Is it typical for a longish shallow run-out from one cycle to run into a Brokeback Mountain upswing like that? (OK, that one hurt just typing it)
How have other cycle rise lengths compared to their prior cycle lengths? Taking the Cycle 23-24 transition value of (144, 44) to a plot of cycles 2-23 (since no official prior cycle exists for cycle 1) it looks like this:

While definitely not out-of-bounds, Dr Hathaway’s prediction does seem to be probing the bottom-most part of the envelope here. In the past, the length of rise for a given cycle has generally been longer if the length of its prior cycle was longer. While it’s NOT a good basis for predicting absolute numbers (pre-emptive nod to Leif), that visible trend in the data point swarm is apparent. Aside from its nearest neighbor of Cycle 20-21 (139, 44), the Cycle 23-24 point is below what has been seen for other cycles following predecessors of 139 months or more (and Cycle 23 would be 5-months longer than Cycle 20). And this assumes a start month of May 2008 for cycle 24. Any delay in that start will push that point into more and more lonely territory, down and away to the right (longer prior cycle, shorter rise to maximum), unless the timing of the predicted maximum slides rightward as well.
By choosing May 2008 for the start of Cycle 24 (again, if I am reading that right), Dr. Hathaway has bought some time for his latest prediction to come true. Activity can stay very low, even at zero, until as late as January 2009 and the smoothed minimum could still occur as predicted. Too much longer after that though, and we may see another revised prediction subtly appear.
So the answer? Yes, there is precedent for this prediction, being the transition of Cycle 20 to 21. No, it isn’t typical, for seven out of the other eight times following a cycle of 139 months or more. Perhaps as good an illustration as any of the difference between “unprecedented” and “unusual”?

And for what it’s worth (or not), my un-educated guess for Cycle 24? A smoothed maximum of around 80, with a rise-to-maximum of around 60 months.

Sorry to be having problems getting links to work. I had some graphs to go along with my prior post, which doesn’t make much sense without them:
The current prediction:
http://i36.photobucket.com/albums/e7/niteowl496/Cycle_23_24_Predict_NASA_MSFC.gif
Dr. Hathaways’s prediction on Waldmeier plot:
http://i36.photobucket.com/albums/e7/niteowl496/Waldmeier.gif
Cycle Rise Length vs Prior Cycle Length:
http://i36.photobucket.com/albums/e7/niteowl496/Rise_vs_Prior_Length.gif
Comparison of cycle transitions:
http://i36.photobucket.com/albums/e7/niteowl496/Cycle_Transitions.gif