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?
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
2008 could have 290 spotless days – but this is unremarkable compared to the 200 to 300 spotless days of the minima of the late 19th and early 20th centuries. Huh?
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.
Silly statement as one should compare equal lengths of time, and the are still 95 days to go in 2008. Take that into account and the ‘projected’ count of blank days should be 200*366/(366-95) = 270 …
Also, remember that 1954 was the minimum before one of the largest sunspot cycles ever recorded, so don’t extrapolate from a quiet Sun to a coming low cycle.
I’m kind of curious about how long it will take for Lief to tell us that everything is normal, and how long it will take before he will consider this minimum to be exceptional.
Neil Crafter (15:06:54) :
2008 could have 290 spotless days – but this is unremarkable compared to the 200 to 300 spotless days of the minima of the late 19th and early 20th centuries. Huh?
1810 didn’t have a single day with spots, so 365 spotless days. That’s what he meant.
I like to use your images of the sun to find specks on my screen.
“Questions about effects on climate are natural if the sun continues to dim.” -Pesnell.
I wonder if Pesnell is already cleaning out his desk at NASA. There are no questions. We already know the answers. our faith in the scientific method says that our hunches and judgements cannot be far wrong. Get a clue Pesnell. When observation undermines your predictions, it is not the time to quake, it is time to dig in your heels deeper!
This is interesting but isn’t the total accumulated number of spotless days (now exceeding 400) more important?
“Questions about effects on climate are natural if the sun continues to dim.”
Dean Pesnell, be careful. At GSFC, you’re (organizationally) awfully close to GISS and James Hansen…
and “AGW” has not yet fallen into the pit of public ridicule it’s headed for this winter.
Yup, not remarkable, nothing to see here, move along.
Story’s author, Dr. Tony Phillips:
“Solar minima this deep and long are common in the historical record and do not represent a fundamental breakdown of the sun’s 11-year activity cycle”
I wonder, how do he know?
When has there been a “fundamental breakdown of the sun’s 11-year activity cycle” and how would we recognize it if this WERE one?
Re Leif Svalgaard (15:16:01) :
Leif; just curious, did you adjust sun spots up by a %, and if so how did you adjust 1810?
It appears the more that is learned, the less is known.
Tilo Reber (15:14:12) :
I’m kind of curious about how long it will take for Leif to tell us that everything is normal, and how long it will take before he will consider this minimum to be exceptional.
Depends on what ‘normal’ is. With only a score of well-observed solar cycles, it is very hard to define ‘normal’. There have been several minima that were quieter.
What is so unusual about this minimum is the amount of interest it has aroused and the amount of hardware we have watching it. That is exciting.
In this story, and the one back in July
” What’s Wrong with the Sun? (Nothing)”
http://wattsupwiththat.com/2008/08/13/spotless-days-400-and-counting/
the author, Dr. Phillips sounds like the person he’s trying to reassure is himself.
David (15:32:36) :
Leif; just curious, did you adjust sun spots up by a %, and if so how did you adjust 1810?
I adjust by a ‘factor’, e.g. 1.15 [also +15%, if you want %], so 0 * 1.15 = 0. This type of adjustment may not be valid for very small sunspot numbers [where it does matter much anyway] as the sunspot number has this discontinuity from 0 to 11.
DR (15:36:21) :
It appears the more that is learned, the less is known.
No, the more questions we know to ask.
I don’t know about a break down of the sun’s 11 year activity cycle but there was a so called lost cycle in the beginning of the Dalton Minimum.
John-X (15:39:53) :
Ithe author, Dr. Phillips sounds like the person he’s trying to reassure is himself.
Yes, he is on record for supporting the Dikpati/Hathaway prediction of a very large cycle so is [like Hathaway] concerned about the lack of spots so far. [although he shouldn’t necessarily be: the very quiet year 1954 was followed by the very large cycle #19].
edcon (15:45:08) :
but there was a so called lost cycle in the beginning of the Dalton Minimum.
No, there is no good evidence for that. On the contrary, 10Be data shows no trace of ‘the lost cycle’. Geomagnetic data also does not support this claim, which is a very old one [goes back to Faye in the 1870s].
I don’t know. When I go blank it usually happens at the worst possible time, though it is a very interesting experience at the very least.
Wouldn’t the number of consecutive blank days be more important than overall days?
The plot above would be more interesting if it showed the number of spotless days in the minimum between each solar cycle and to go back at least 150 years. That would really show where this quiet period ranked.
Leif Svalgaard (15:42:44) :
correction, of course:
David (15:32:36) :
Leif; just curious, did you adjust sun spots up by a %, and if so how did you adjust 1810?
I adjust by a ‘factor’, e.g. 1.15 [also +15%, if you want %], so 0 * 1.15 = 0. This type of adjustment may not be valid for very small sunspot numbers [where it does not matter much anyway] as the sunspot number has this discontinuity from 0 to 11.
Dr Leif, please:
Today, What your deadline?
Dr Leif speaking:…. This is a significant delay.(C24)
FM
“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?
Isn’t solar cycle legth a “fair” kind of temperature proxy, or is solar Minimum length a better one?
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?