I used to completely be a complete believer in dangerous CO2-driven global warming after I saw shrunken glaciers in the Rockies in the 1980’s. Then I found out soot has been melting them, the Arctic & Kilimanjaro & started to wonder what was up. Then I saw Gore’s movie & realized we were being stampeded.

I think we need to send Al Gore on the mitigation mission to steer Apophis after it passes by in 2013. Doesn’t matter if Apophis will miss or not in 2039, we need Al Gore to be selected in consideration of his humanitarian heroism:

“Houston. We have a problem. The return booster won’t fire.”

“Roger that Apophis Base. We have studied the problem and we’ve determined that the booster is actually full of copies of AIT.”

“Sorry Houston. Could you repeat that last transmission?”

[silence]

“Apophis Base to Houston command, do you copy?”

[silence]

etc…

We’ll all remember him as a hero.

The next questions. Has cloud cover started to increase? If so, what type?

If we are facing another minimum, I vote to name it “The Gore Minumum”.

Anyone know how much average solar luminance decreased since 1990? Apparently this slight 17-year decline is seen as responsible for a “mere” -0.1 degrC change, or about 0.06 degrC per decade. Understood this is only in the context of steady, full-amplitude solar cycles of the 20th century, meaning periodic minima wouldn’t pull the average down as much.

Longer minima, in a lower-frequency & half-amplitude multi-cycle trend, on the other hand, would a more-significant cumulative effect, proportionately. There must be some data and formulas for this. I would expect a multiple of the -0.06 C/decade.

Shindell at NASA/GISS modeled this back in 2001 and found the Maunder would cause far-more colder continental winters.

The bottom line was that the diminished solar luminance slowed interzonal convection and increased La Nina frequency & a generally lowered heat budget which lead to weaker continent-warming ocean-borne weather fronts in wintertime. While the cooling was modest, the effects in continental
interiors were profound. Likewise SC Asia has a historical record of famine corresponding with declines in solar luminance.

http://www.giss.nasa.gov/research/briefs/shindell_06/
http://www.giss.nasa.gov/research/news/20011206/

“…They determined that a dimmer Sun reduced the model’s westerly
winds, cooling the continents during wintertime. Shindell’s model
shows large regional climate changes, unlike other climate models that
show relatively small temperature changes on an overall global scale.
Other models did not assess regional changes.”

Shindell’s study found a 0.3-0.4C GST change, which might be about right, compared to this -0.06 current changee. I suspect Shindell’s study, were it run again, would show a lower GST outcome, taking cosmic rays and ocean effects into account. The upshot would be either to make the continental temperature model outcome more consistent, colder, or both.

This model was run in 2001, so it probably didn’t include cosmic ray influences on cloud cover, ocean-air coupling, PDO, AMO, NAO, AO or bigger La Nina effects.

Even skeptics of cosmic ray influence admit CRF can account for as much as 25 percent differential in cloud cover between 20th century solar min & max. A 25 percent differential is not enough to do it all, but it’s a nice nudge either way.

I think it can be reasonably assumed that SC#25 will be a half-amplitude dud, and I think it’s fair to guess likewise SC#26. Solar activity changes of this magnitude evolve over the course of several decades, so this evolving downtrend may be with us for a good while.

But for the time being my guess is the sun’s dimming marks the onset of a moderate Dalton- or Sporer-like grand minimum. That seems to me more probable than a deep-chill Maunder.

Over on El Reg on the Tale of Two Thermometers thread at http://www.theregister.co.uk/2008/05/02/a_tale_of_two_thermometers/comments/ Evan went British, paraphrasing G&S with “Not to mention that solar cycle 24 is the very model of a modern major minimum.”

Jolly good, ol’ chap!

Mike

with more correlations of sunspot length with temperatures

Look at fig 13 in http://nzclimatescience.net/images/PDFs/archibald2007.pdf

There are more of these simple plots, but I do not have the link. I think he presented them at the conference in march.where people have records for two centuries of both temperature and number of sunspots and the length of the cycles. Nothing fancy, but consistent. The longer the cycle the colder the next period.

BTW Soho has updated the magnetic view. The spot is still there.

SC24 start with the first spot. However we only reach minimum when the number of SC24 spots is greater than the number of SC23 spots. So the general discussion is when due we reach minimum? Make me wonder is the Maunder minimum had these very small spots and they just couldn’t see them.

As an amateur astronomer maybe you would know: Would a telescope at the time of the Maunder Minimum have been able to resolve sunspots this small?

I’m not an astronomer of any sort but I would imagine that the duration of a sunspot would also play a part as to whether it would have been detected. In the past a spot would only be visible if the sun was not obscured by clouds. The smaller the duration the greater the chance that the sun would be obscured for the spots entire lifetime.

REPLY I’ll add it to the pile

There’s a good chance I wouldn’t have seen it at its best, anyway.

I don’t recall Keenlyside et. al. mentioning anything about solar energy fluctuations in their press release. Are they recognising the sun is now a factor?

“As an amateur astronomer maybe you would know: Would a telescope at the time of the Maunder Minimum have been able to resolve sunspots this small?”

Look up the drawings of people like Jan Hevelius, who observed sunspots at that time. I don’t think they would have detected it. I used a 60mm apochromatic refractor (i.e. pretty sharp optics), but it was very hard to see it visually, even when I knew it should be there. I saw it with some difficulty.
Granted, the seeing wasn’t ideal, but all in all I doubt that this spot would have been detected during the Maunder minimum.

So if we are comparing with Maunder minimum sunspot counts, I think we should be careful jumping to quick conclusions. The minimum could be many months into the future still.

Not a chance. Galileo’s telescopes were barely able to resolve the rings on Saturn. In a modern telescope amateurs might own Saturn is wonderful jewel in the sky – oblate disk with elliptical disk for the rings. Traces of texture on the planet, fairly easy to see the Enke division in the rings. Saturn’s rings are about 40 arc-seconds across, the Sun is about 1800, I’d guess those Tiny Tims are about 5. With all the turbulence during daytime, I’m not sure Carsten could see the spot well with direct viewing, that’s one reason his image is a stack of 600 separate images.

See http://www.princeton.edu/~rvdb/images/Questar/saturn.html
for some Saturn images from an over-achieving small (3.5″ aperture) scope.

I don’t even know yet what the number is. Do these “count”? what’s the total?

I am not panicking Mt. Wilson is on the job with paper and pencil reporting on #993. Apparently they work on weekends. I just can’t participate in all the fun!
http://www.astro.ucla.edu/~obs/images/cur_drw.jpg
ftp://howard.astro.ucla.edu/pub/obs/drawings

No MDI sighting yet and we are coming up on 24 hours.

SIDC is now tracking #993 which is now over 36 hours old, if it is still there. I wonder is SIDC closes for the weekend?

Mike