From NASA Science News h/t to John-X
Spotless Sun: 2008 is the Blankest Year of the Space Age
Sept. 30, 2008: Astronomers who count sunspots have announced that 2008 is now the “blankest year” of the Space Age.
As of Sept. 27, 2008, the sun had been blank, i.e., had no visible sunspots, on 200 days of the year. To find a year with more blank suns, you have to go back to 1954, three years before the launch of Sputnik, when the sun was blank 241 times.
“Sunspot counts are at a 50-year low,” says solar physicist David Hathaway of the NASA Marshall Space Flight Center. “We’re experiencing a deep minimum of the solar cycle.”
Above: A histogram showing the blankest years of the last half-century. The vertical axis is a count of spotless days in each year. The bar for 2008, which was updated on Sept. 27th, is still growing. [Larger images: 50 years, 100 years]
A spotless day looks like this:
The image, taken by the Solar and Heliospheric Observatory (SOHO) on Sept. 27, 2008, shows a solar disk completely unmarked by sunspots. For comparison, a SOHO image taken seven years earlier on Sept. 27, 2001, is peppered with colossal sunspots, all crackling with solar flares: image. The difference is the phase of the 11-year solar cycle. 2001 was a year of solar maximum, with lots of sunspots, solar flares and geomagnetic storms. 2008 is at the cycle’s opposite extreme, solar minimum, a quiet time on the sun.
And it is a very quiet time. If solar activity continues as low as it has been, 2008 could rack up a whopping 290 spotless days by the end of December, making it a century-level year in terms of spotlessness.
Hathaway cautions that this development may sound more exciting than it actually is: “While the solar minimum of 2008 is shaping up to be the deepest of the Space Age, it is still unremarkable compared to the long and deep solar minima of the late 19th and early 20th centuries.” Those earlier minima routinely racked up 200 to 300 spotless days per year.
Some solar physicists are welcoming the lull.
“This gives us a chance to study the sun without the complications of sunspots,” says Dean Pesnell of the Goddard Space Flight Center. “Right now we have the best instrumentation in history looking at the sun. There is a whole fleet of spacecraft devoted to solar physics–SOHO, Hinode, ACE, STEREO and others. We’re bound to learn new things during this long solar minimum.”
As an example he offers helioseismology: “By monitoring the sun’s vibrating surface, helioseismologists can probe the stellar interior in much the same way geologists use earthquakes to probe inside Earth. With sunspots out of the way, we gain a better view of the sun’s subsurface winds and inner magnetic dynamo.””There is also the matter of solar irradiance,” adds Pesnell. “Researchers are now seeing the dimmest sun in their records. The change is small, just a fraction of a percent, but significant. Questions about effects on climate are natural if the sun continues to dim.”
Pesnell is NASA’s project scientist for the Solar Dynamics Observatory (SDO), a new spacecraft equipped to study both solar irradiance and helioseismic waves. Construction of SDO is complete, he says, and it has passed pre-launch vibration and thermal testing. “We are ready to launch! Solar minimum is a great time to go.”
Coinciding with the string of blank suns is a 50-year record low in solar wind pressure, a recent discovery of the Ulysses spacecraft. (See the Science@NASA story Solar Wind Loses Pressure.) The pressure drop began years before the current minimum, so it is unclear how the two phenomena are connected, if at all. This is another mystery for SDO and the others.
Who knew the blank sun could be so interesting?
Tom. I guess not… The number of consecutive days should depend on distribution, which I guess is somewhat arbitrary.
Booth 2007 and 2008 gets medals; gold and bronze respectively. A bit scary…
edcon (15:45:08) :
“but there was a so called lost cycle in the beginning of the Dalton Minimum.”
I think Jan Janssens gave that idea a fair treatment.
http://users.telenet.be/j.janssens/MSCwebEng.pdf
I think you really have to argue for the existence of something like midget cycles, and if you do that for the alleged missing cycle between 4 and 5, then you also have to treat similar patterns as also being midget cycles, and so start combing the sunspot records for them.
Magnus (16:24:07) :
” Isn’t solar cycle length a “fair” kind of temperature proxy, or is solar Minimum length a better one? ”
Leif will say “Neither.”
And it is quite true that correlations between solar activity and climate are just that, correlations.
A few physical mechanisms have been proposed to explain the correlations, but none has been proven.
It’s going to become “obvious” to everyone this winter that the inactive sun is responsible for colder climate, just as it is “obvious” to so many now that human activities cause warming.
It’ll still take several years for the supertanker of grant money to turn from “man-made global warming” to actual climate research.
Fernando (16:23:03) :
Dr Leif, please:
Today, What your deadline?
Dr Leif speaking:…. This is a significant delay.(C24)
You lost me…
Magnus (16:24:07) :
“Dalton” or “Maunder”?
When does this solar cycle becomes longer than the solar cycle in the end of the 18th century which “started” the Dalton Minimum? Late this year, or later?
That cycle went from 1784.2 to 1798.5 for a length of 14.3 years, so we still have a ways to go [except that the old data are not all that accurate…]
Isn’t solar cycle legth a “fair” kind of temperature proxy, or is solar Minimum length a better one?
none of them any any good.
30
09
2008
A.Syme (16:30:40) :
I 1957 I signed up (at age 13!) to be an official aurora borealis observer for the IGY (International Geophysical Year) it was the height of my scientific career . I remember toward the end of the year there was a call to do another geophysical year during the solar minimum, The Year of the Quiet Sun. I cannot find any info that this was actually done. Does anyone out there have an info on this?
I forgot you:
A.Syme (16:30:40) :
The Year of the Quiet Sun. I cannot find any info that this was actually done. Does anyone out there have an info on this?
There was such an effort: IQSY, google that
I wonder what today’s count of spotless days would be if we were using the same instruments, methods and definitions that were used in 1810?
John-X (16:38:32) :
I think you really have to argue for the existence of something like midget cycles
There are always ‘bumps’ in the any record. what is important here is whether the magnetic field changed polarity, and it didn’t as per the cosmic ray record.
If we choose a two-year period as our timebase, how does 2007-2008 stack up?
I mean, it clearly crushes the recent years, but how does the current 24 month period rank versus the longer historical record?
Spotless days for 2008 looks like it will rival the period of 1911 to 1913 (200 to 300 spotless days) in which temperatures were 1.0C lower than today – the coldest sustained period of time in Hadley’s temperature dataset going back to 1850.
Hopefully the currently high spotless day count doesn’t last for another two years (although 2007 is already in the top 10 spotless day years so maybe we are already into year 2 of the high counts.)
Well, assuming that Sept. 30 is spotless, as well as October 1st, and cycle 24 will have more spotless days (447) than solar cycle 19 (446) according to Janssen’s website.( http://users.telenet.be/j.janssens/Spotless/Spotless.html)
cycle 24 will then have more spotless days than any cycle since 17, about 75 years. Another 120 days of spotlessness would be needed to beat cycle 17, at 568.
While it is certainly possible that cycle 24 will be a big cycle like 19, I’m confident that Dr. Svalgaard’s research is more correct than Dr. Dikpati’s and that solar cycle 24 will have a maximum smoothed sunspot number somewhere between 50-85. In some ways I am hoping for a Maunder minimum, since those tend to be rare and we could learn more interesting science. Tough, possibly, on the human race if there is a correlation between a Grand Minimum and global cooling, but still nice for science.
Maybe the Sun is just taking a break, after a pretty busy half-century. The hurricane guys have their ACE index (Accumulated Cyclone Energy) to compare periods of activity…perhaps an Accumulated Smoothed Sunspot index might have a bit to do with higher temps in the late 20th century (almost 50% higher than any other “half-century” measured).
http://i36.photobucket.com/albums/e7/niteowl496/AccumulatedSSN.gif
[…] to it than that, and some contention, as Leif Svalgaard weighs in with knowledge and opinion on Watts Up With That? in the […]
We didn’t have the data then we do now, so we really don’t know what this relates to, except that it’s far from over. Spotless days are only 1 statistic in a sea of many likewise taking us back a long time, some to 200 yrs ago, some to only 50.
Summary: All we know is a “so far” comparison.
The chart is a bit deceiving, for solar minima that span multiple years, the totals are different.
1911-1913 is over 750 days,
2007-2008 is over 350 days,
1985-1986 is about 200 days
1975-1976 is about 200 days
1964-1965 looks to be just under 200 days.
These are estimates based on the chart, real data would be nice.
A better graphic would be the number of spotless days for each solar minima.
Hard times,
Are coming,
Your town….
Leif Svalgaard:
Maybe a better analogy: knowledge is like an expanding balloon. As knowledge increases, the area outside the balloon — the unknown — also increases.
200 years is a long time in the history of a 5 Billion year old star? The “so far” comparison is like a nanosecond yet creates amazing speculation about Sol and climate. The ice age is coming baby, but humans are not the cause.
P. Hager (19:22:24) :
A better graphic would be the number of spotless days for each solar minima.
Here are my counts. They start after the 10th spotless day for other reasons]. So you may want to add 10 to each.
end of cycle#
6 1457
7 479
8 464
9 646
10 397
11 1018
12 728
13 924
14 1015
15 525
16 559
17 260
18 437
19 218
20 263
21 264
22 300
23 429
you can see the graphic here
These numbers are very sensitive to the [uncertain] visibility of small spots early on, so should be taken with a lot a salt.
Is it just me, or is Leif’s graph scarey?
What’s with all the 23-24 peaks?
Tom in Texas (20:13:34) :
Is it just me, or is Leif’s graph scarey?
What’s with all the 23-24 peaks?
They are not any bigger than many of the other peaks. They go up and down a lot. That is just because for the last several years we have have bunches of spots from SC23 [that drag the plot down] separated by periods of calm [that pull the graph up to a peak].
Leif: What are the areas under the curves for the 1st 30 months?
Tom in Texas (20:29:40) :
What are the areas under the curves for the 1st 30 months?
sum @ur momisugly 30 months
6 144
7 188
8 209
9 79
10 94
11 134
12 223
13 145
14 254
15 328
16 353
17 240
18 314
19 142
20 172
21 248
22 223
23 297
median 209
what is so special about 30 months?
“So far” as in ongoing spotless days continuing to stack up, where she stops, nobody knows.
Another year of this is not out of reason, and neither is another 30 days and it all ends.
Leif: Unless I misunderstand your graph, the 23-24 minimum looks to be about 30 months old. Just wanted to compare where we are at now vs previous cycles. Looks like only 15 & 16 have 23 beat.
Leif Svalgaard (19:46:30) :
Thanks for the summary. Based on your numbers, Cycle 23 is exceptional only when compared to cycles 19 through 22. When compared to the entire set, cycle 23 still has fewer spotless days than over half of the cycles from 6 to 22. It looks likes cycle 23 still needs at least another 51 spotless days before it has more spotless days than half of the cycles from cycle 6 on.