The sun is blank–no sunspots.
Several WUWT readers have inquired about why the SOHO MDI and magnetogram image has not been updated in several days. The last update was on July 28th.
Here is the reason:
Solar and Heliospheric Observatory (SOHO) is having a minor problem. SOHO’s white light solar telescope is temporarily offline while new commands and data tables are uploaded to the spacecraft. Normal operations are expected to resume in a few days.
h/t to:
So? Did we miss a sunspot?
REPLY: not that I am aware of. We still have ground based telescopes – Anthony
Having taken Watts down, Sinclair takes on EPA’s Alan Carlin in his latest Crock of the Week video
http://climateprogress.org/
These guys could have damaged the SOHO MDI…they seem destructive, eh?
I check the images at STEREO daily anyway, we haven’t missed anything.
Consider me an illiterate if you must, but what does SOHO tell us that, say, Sac Peak doesn’t?
You can still see the Sun in other wavelengths on teh SOHO page; I always go as well to the STEREO web page, which shows the Sun some 30 degrees round each corner.
Spotless Days
Current Stretch: 25 days
2009 total: 167 days (77%)
Since 2004: 678 days
Typical Solar Min: 485 days
2009 just passed 1890 and could we be in for a repeat of the 1900’s?
2007 – 1911
2008 – 1912
2009 – 1913
Could be in the a spotless summer, and fall, and winter
WIth the current run of 25 spotless days, the sun seems quieter than it has been for some time. Can anyone tell me how this compares with the length of other spotless periods during the present minimum? I might be wrong, but I have the impression that this has been one of the longest spotless intervals so far.
This would be somewhat OT in most threads here (this one, hopefully not so much), but I have a rather fundamental question about the basic mechanics of AGW theory.
As I understand it, in oversimplified fashion, atmospheric CO2 absorbs certain wavelengths of EM radiation. Increasing the concentration of CO2 will thus increase the temp of the air by increasing the total radiation absorbed.
The NIPCC chart referenced in the earlier post by Ron House predicts the largest temp increase in the zone from 6 to 14 km altitude. The mythical ‘Red Spot’.
Even if this extra warming is taking place, wouldn’t it just all radiate to space every night as the atmosphere returns to an equilibrium in that area? With the exception of cirrus type clouds, pretty much everything else is below 6 km, so the heated air might be considered to be ‘outside the blanket’, so to speak.
As Ron House pointed out, analogies are never perfect, so here’s mine. If I leave a brick out on my porch in the sun for the day, it will grow warm. Overnight, it will cool to the ambient temperature. Take another brick and put it in the oven, and heat it to 400 degrees. At sunset put it outside with the sun warmed brick. By dawn, the two bricks will both be at the ambient temperature. In fact, I could have warmed the second brick in a kiln and it still wouldn’t have made any difference the next day. I would not have any residual Anthropogenic Backyard Warming by cooking the bricks, even if I did it every day.
What am I missing? At the end of the day (heh!) maybe the air is warmer. But certainly by astronomical dawn the next day any extra heat is long gone along with the normal energy release quota. Where I live, the air cools more on a cloudless night than on a cloudy one. As long as the extra heat is above any clouds, I’d think it’s likely gone a few hours after sunset.
Mike
A good source for spotless days info that I found is http://users.telenet.be/j.janssens/Spotless/Spotless.html
The table “Periods with spotless days (>20 days) since 1849” from that site give an overview of spotless periods.
SC 24 has had 8 spotless periods as of May 2009.
SC 24 has had 8 spotless periods “of 20 days or more” as of May 2009. My typing got ahead of my thinking.
Laurence Kirk, you are correct, it is one of the longest so far. It ranks as the 4th longest currently at 25 days. Longest this minimum was 31 days.
Longest spotless period among the modern cycles is 42 days during minimum 1996. It was the only 20+ days spotless period for that minimum. This one is counting 9 so far including the current unfinished spotless period.
Just as the sun looked like it was ramping up, it is getting closer and closer to set a new spotless period record while the solar flux seems to be dropping sligtly again.
For some sunspot statistics, check this page out:
http://users.telenet.be/j.janssens/Spotless/Spotless.html#Period
Thanks guys. Now I can pursue my occasional distraction by spaceweather.com even more indulgently! Every time they add another spotless day, I seem to get a little dopamine hit..
With regards,
Larry Kirk
Jerker Andersson (13:04:51) :
For some sunspot statistics, check this page out:
http://users.telenet.be/j.janssens/Spotless/Spotless.html#Period
It is an interesting page indeed. If the page is updated like the last couple of years, the next update should be early September, a month from now.
The blue spotless days graph is competing with ~1911
http://users.telenet.be/j.janssens/Spotless/Spotless.html#Wolf
Will the green curve of accumulated spotless days reach 700 before the next update of the spotless days page? Maybe 800 by new year?
http://users.telenet.be/j.janssens/Spotless/Spotless.html#Evolution
Laurence Kirk (12:45:11) :
25 days is a run, no doubt about it. There were 2 phantoms, but they can be ignored. SWPC/NOAA caught on, and ignored them.
I ignore them too. Credit Geoff Sharp for the idea and the energy to drive the project forward.
As for runs minus the phantom spot counts, 2008 had 60+ spotless day run and 2009 has had a 60+ day run.
Knowing that spots in this minimum can grow out of nothing, you might as well flip a coin to say whether we’ll get another 60+ day spotless run minus the phantom spots. The way it looks right now, there’s nothing going on.
SOHO is a great tool in space. It will be back. I wouldn’t mind if NASA ordered a dozen of them for backups and to keep a SOHO eye on the backside of the Sun. There’s nothing like consistency, and SOHO has given it to us.
MikeW (12:54:45) :
In your analogy, the brick does cool but the AGW theory is that a part of the heat is trapped by the green house gasses.
I would refer you to Dr. Spencer’s blog at:
http://www.drroyspencer.com/
Click on “Global Warming 101”.
It is well written so that even a humble red-neck from Texas (like me) can understand it.
Regards,
Steamboat Jack
Laurence Kirk (12:45:11) :
WIth the current run of 25 spotless days, the sun seems quieter than it has been for some time. Can anyone tell me how this compares with the length of other spotless periods during the present minimum? I might be wrong, but I have the impression that this has been one of the longest spotless intervals so far.
~~~~
You may find this trend graph over at Solarcycle24 interesting. It hasn’t been updated yet for July, and it doesn’t tell you the length of spotless intervals. It does give the number of spotless days in any given month and contrasts those with the SC23 minimum.
http://www.solarcycle24.com/graphs/sunspotgraph.gif
I would put the brick in the greenhouse, not on the doorstep! But then take the roof off the greenhouse, to allow for natural convection..
(after which, if we’re having a cold snap, even the greenhouse won’t save the tomatoes)
Leif, what is your take on what they call faculae regions (FR)?
The Australians have an interesting explanation… http://www.sydneyobservatory.com.au/blog/?p=2260
… and they seems to say that there was a very small sunspot (very hard to see through) this week.
The Hathaway August 2009 Sunspot Number Prediction has been released… Looking at the curve, Maximum is now expected to be in early 2013 with a sunspot number +- 82.
Flux is pretty low today (unadjusted of course!) at 66.
jon Jewett (13:50:33) :
In order to get warmer, you have to trap more of the outgoing than at present.
That was predicted to occur in the tropics. Didn’t happen.
We’re leaking heat like a sieve.
Kind of like your monthly balance: You have to spend less than you earn in order to save up.
We’re losing jobs faster than they are created. It’s called an unemployment rate. Makes pay rates go down, and makes it harder to save. We’re leaking jobs like a sieve too.
The spotless days page was updated 2nd of May. There was a long spotless period still underway as of the 2nd of May and is not yet counted on the charts – longer the 31 days.
If the current spotless period extends longer than J.Jansens update of the 2nd of September then it will not be counted until his December update.
It’s also possible that the total solar cycle 24 spotless days count will surpass cycle 15’s. – just over 25 odd days to go.
Meanwhile there is a Volcano with a remote potential of a St Helen’s sized eruption being monitored on the Kamchatka peninsula.
When do you think the next La Nina will come around? How long do you think this El Nino event will hang around? (Assuming it develops into an established event)
Hi Mike, I am a believer in ‘outer envelope’ type calculations. What this means is, to use a simple example, if I have a full bucker of water and there’s a hole in the bottom of the bucket, I predict the bucket will soon be empty. I could have analysed the details of fluid flow through a narrow opening, but all that would do is give me a better estimate of what I can predict anyway. Now CO2 has one significant absorption band in the infrared region, which is used by most of the heat radiated from the surface. So that reduces the total ‘power envelope’ of the planet’s radiation. So the surface must heat up by just enough that the rest of the power envelope adjusts for the missing bit absorbed by CO2.
The reason the molecules heated by day don’t simply reradiate at night is that they indeed do, but the photons radiated will hit another CO2 molecule in short order and get absorbed again. In fact the hot air rises, and only molecules high enough to have a ‘clear line of sight’ to outer space will succeed in radiating their energy away. Whatever the temperature of that layer, that is the effective temperature at which the Earth radiates in the CO2 absorption band.
I think the main thing is that solid objects tend to absorb and radiate at almost any wavelength, whereas the atmosphere only does do at certain wavelengths. Most of the contents of the air (N2, O2) cannot radiate or absorb at all in the relevant range, so unless they can get rid of heat by convection or conduction or giving the heat to a CO2 molecule, say, that can radiate, they just keep their heat. (In fact, the air as a whole convects nicely and cools as it rises.)
“In your analogy, the brick does cool but the AGW theory is that a part of the heat is trapped by the green house gasses.”
In my simple way of thinking, we’re looking at 3-4% CO2 in the atmosphere. Imagine a blanket 4′ x 8′ – with only 1 square foot of material spread out over the 32 square feet of the blanket. Pretty crappy blanket – so what’s the real theory on AGW?
A good time for maintenance, indeed.
Correction here.
So called greenhouse gases make up only 2% of total atmosphere
Total CO2 makes up only 3.62% of total greenhouse gases.
“Anthropogenic” CO2 makes up 3.4% of the total CO2 inside the total greenhouse gases.
Insignificant.
“”” MikeW (12:54:45) :
This would be somewhat OT in most threads here (this one, hopefully not so much), but I have a rather fundamental question about the basic mechanics of AGW theory.
Even if this extra warming is taking place, wouldn’t it just all radiate to space every night as the atmosphere returns to an equilibrium in that area? With the exception of cirrus type clouds, pretty much everything else is below 6 km, so the heated air might be considered to be ‘outside the blanket’, so to speak. “””
Mike, I would like to personally ring the neck of whoever it was who started the mythology that the earth absorbs solar energy during the daytime and radiates thermal energy at night to cool down.
The earth that I live on absorbs solar energy 24 hours per day, 365 1/4 days per year, non-stop; and it also happens that it radiates 24 hours a day 365 1/4 days per year; but whereas the incoming solar energy only falls on about 1/2 of the total earth surface at any one time; the outgoing radiation occurs from the entire surface continuously without stopping.
And just for good measure it does its best radiating in the mid day to afternoon peak sunlight, and from the hottest tropical desert areas of the earth. That also includes Urban Heat Islands which are also excellent thermal radiators and cool fastest during the daytime high temperatures.
There isn’t any on-off switch that tells the earth that the sun has set, and it is time to fire up the radiator, and start emitting thermal radiation in the long wave IR band.
It is true that during the peak daylight hot hours, it might be somewhat difficult to measure the thermal radiation against the background of incoming solar radiation; but it is there none the less.
The earth’s polar regions are by comparison pikers when it comes to cooling the earth, and radiate as little as 1/12th of the peak sunlight tropical rates.
George
“”” Ron House (16:38:03) :
MikeW (12:54:45) :
>>>
I think the main thing is that solid objects tend to absorb and radiate at almost any wavelength, whereas the atmosphere only does do at certain wavelengths. Most of the contents of the air (N2, O2) cannot radiate or absorb at all in the relevant range, so unless they can get rid of heat by convection or conduction or giving the heat to a CO2 molecule, say, that can radiate, they just keep their heat. (In fact, the air as a whole convects nicely and cools as it rises.) “””
So who gave the atmosphere a special dispensation to not radiate the same as the solid surface does; or are you saying that the incoming solar spectrum proves that the sun is a solid object.
The thermal continuum spectrum of radiation that is emitted from ALL bodies that are at temperatures above zero Kelvins, does not care what the materials are. The source of that radiation is believed to be due to the acceleration of electric charges which all materials contain,a nd since they are thermally agitated at temperatures above 0 Kelvins; they most certainly contain accelerated charges.
Nobody tells the sun it cannot radiate thermal radiations until it decides to solidify.
And I note once again that materials never stop radiating; they do not wait till sunset to decide to radiate; and they do their best radiating during the hottest daylight hours.
George
Or put another way.
If the total atmosphere depth was represented by a 110 story building, the “anthropogenic” CO2 would add up to the thickness of the polish on the linoleum on the basement floor.
Not much of a blanket for you.
I wonder how much longer SOHO will last. And is there a direct replacement in the pipe or once gone it gone and will have to uses different sources. I use it as a homepage.
The missing holographic image is like the loss of a sonogram.
That is true, but the amount of absorption or emission is moderated by the closeness of a body to a black body. Shiny aluminium, for example, reflects well and emits poorly for this reason: it doesn’t resemble a black body. If you look at, e.g. http://www.williams.edu/astronomy/research/PN/nebulae/legend.php you will see that typically discrete emission lines very much dominate over continuous emission. If you had looked back at the post I was answering, it should have been obvious I was simplifying to make the case in the ordinary Earth atmosphere intelligible. You will be aware that absorption and emission are symmetric processes. Therefore the relative transparency of O2 and N2 to continuous radiation in the infrared tells us that continuous emission is going to also be a minor player at these temperatures. However, pretty much every solid substance comprising the surface of the Earth absorbs infrared, and therefore must also radiate it equally well. That was the basis of my simplified comments: continuous emission from the Earth’s atmosphere can be ignored compared with the discrete emissions of the greenhouse gases or continuous emissions from the surface. It is not normal to write university-level lectures on blog comments in answer to questions from laypeople struggling to understand basic issues, so I do consider your comments on my previous comment to be nitpicking.
Perhaps there wouldn’t have been so much global warming if Mike W hadn’t been putting all these red-hot bricks on his porch.
“Even if this extra warming is taking place, wouldn’t it just all radiate to space every night as the atmosphere returns to an equilibrium in that area? With the exception of cirrus type clouds, pretty much everything else is below 6 km, so the heated air might be considered to be ‘outside the blanket’, so to speak.”
A very good point, the heated air rises (if not already in a large height) and radiates the heat (or a part of it) into space. These radiation takes only place because of the greenhouse gases! No greenhouse gases -> no radiation to space of the atmosphere! The mechanism is just neglected by the climatists!
Prof. Teuschner (one of the first sceptic scientists) gives a good example for such a mechanism:
You have a very hot hotplate on your stove, beyond is nothing. Then you take your kettle with the “greenhouse-fluid” water and put it on the hotplate. What happens? The hotplate cools down!
” By dawn, the two bricks will both be at the ambient temperature. In fact, I could have warmed the second brick in a kiln and it still wouldn’t have made any difference the next day. I would not have any residual Anthropogenic Backyard Warming by cooking the bricks, even if I did it every day.”
You are right, but the earth is not a brick, the water is storing the heat very well (high heat capacity). E.g. on the moon behaves like a brick, in the “night” the surfaces cools down much much more than on earth
I think the point with GHG warming is not just that that CO2 absorbs IR energy, but that it gives an opportunity for that energy to become thermal (i.e. mechanical energy). If all that were to happen with the photon was that it was re-emmitted or reflected when it hit a molecule, then the temperature of that molecule would change only for the brief second it had absorbed the energy and then return to normal when re-emitted.
However, as someone correctly pointed out above their are multiple modes by which this energy can be re-emitted. It can be as IR or in the case of two molecules colliding, it can be mechanical. If a CO2 and O2 molecule collide, at least part of that energy is transferred to the O2 molecule. The O2 molecule now has a higher energy state than it did before and so does our atmosphere (of two molecules in this example) as a whole because the energy coming in was not re-emmitted.
Now with GHG warming, the other thing that is important is concentration of molecules. Lets take a box of 100 O2 molecules and 1 CO2 molecules. There is a lot of empty space between those molecules. If IR hits the CO2 molecule, but is re-emmitted before the CO2 can transfer that energy to an O2 molecule, then the energy state of the box will not go up. Now lets say that I add anothe CO2 molecule to the mix. I have just increase my chances of that energy being transferred to an O2 molecule because one, I’ve double the chances of the initial IR photon of striking a CO2 molecule and I’ve infinitely increased that chance that a re-radiated photon might hit another CO2 molecule (before there was not a second one to hit). So as you increase the concentration of GHG the amount of heat lost from the system in the form of re-radiated IR will go down.
Now here’s the final thing. The first time you added one molecule, you greatly increased your chances of the IR photon being caught by the system. When you add another one, you will also increase the chances, but not by as much as the first time. In order to increase your chances by the same amount as the first time, you will have to double the concentration of CO2. So to get the same amount of warming of the system from 1–> 2 molecules you will have to go from 2 –> 4 molecules. Then from 4–>8 and then 8–>16 etc… This is why you see metrics like 1.2degrees warming/doubling of CO2.
There is not really a question as to whether or not CO2 affects the temperature of earths atmoshpere, or whether or not we have added to that CO2. It does and we have. To suggest otherwise is silly. The main argument that many people stress is that runaway warming (i.e. castastrophic warming) relys on strong positive feedbacks, which to this date have not been proven (or disproven for that matter).
” apb (16:47:54) :
…
In my simple way of thinking, we’re looking at 3-4% CO2 in the atmosphere. Imagine a blanket 4′ x 8′ – with only 1 square foot of material spread out over the 32 square feet of the blanket. Pretty crappy blanket – so what’s the real theory on AGW?”
” Les Francis (18:11:50) :
…
So called greenhouse gases make up only 2% of total atmosphere
Total CO2 makes up only 3.62% of total greenhouse gases.
“Anthropogenic” CO2 makes up 3.4% of the total CO2 inside the total greenhouse gases.”
So…the technical word for this fabric analogy might be…LACE.
🙂
“Illusion” might be a better word (the descriptive name of veil netting). Lace can be pretty opaque. So says the seamstress.
@ L. Bowser
The Greenhouse-theorie doen’t claim a direct heating of the atmosphere, i.e. this is only a small part of the claimed heating. It says, that most of the absorbed energy is re-emitted. Because half of the re-emitted radiation is towards the surface of the earth, the surface is becoming warmer.
But here is a tricky point: The radiation is not heating up the surface (not possible because the emitter is colder than the surface). The surface is radiating less energy, because of the incoming radiation of the GHGs. So the GHGs act like a insulation to the surface.
I wonder, has anybody thought to observe the sun both the old technology way, and the new way and see what happens to the tiny-spots? Can the tiny-spots even be observed with the old way technology?
Would be interested to find out. Like with hurricanes, the new technology often completely shifts the data and makes it very hard to compare past data to today.
All you really have to do is count sunspot groups rather than sunspots. Those supposedly relate somewhat consistently to total number of spots and they are observable by both old and new technology.
Trevor (tjexcite) (19:57:30) :
SOHO falls along the same lines of Hubble vs the new Infrared Telescope (James Webb).
Both the Scientists who use Hubble and the public were aghast that NASA was going to scrap visible light imaging in favor of IR only.
We need a simple, reliable, easily replacable imager in space to keep an eye on the Sun free of the atmosphere. The last aspect of SOHO, free of seeing constraints, is it’s biggest asset.
tarpon (07:56:14) :
I wonder, has anybody thought to observe the sun both the old technology way, and the new way and see what happens to the tiny-spots? Can the tiny-spots even be observed with the old way technology?
If you mean project instead of observe, the answer is yes, there are those of us who have thought about it and attempted to address it.
http://www.robertb.darkhorizons.org/DeepSolarMin5.htm
In the days of speculum mirrors and pre-achromat, that’s a big no on Tiny Tim detection.
In the days of the early achromats, still no, as today’s cheap achromat will run the originals off the road, and the Tiny Tim’s are not projectable. Even today’s eyepieces are a critical component. Ramsden, Kellner and Huygens eyepieces, but no Plossl, Erfle, Orthos.
Today, with the advanced optics and or imaging trains, it’s very easy to pick up a group of spots so weak that they were invisible 150 + yrs. ago.
Leif, what about the size of the sun? Does it change over time and are we able to measure it precisely?
@ Johnny Honda
I’m no expert in GHG theory, but I’m pretty sure that it happens roughly the way I am saying, otherwise the mechanism wouldn’t work, and it does work, otherwise earth’s temperature would be unsustainable. I know Wikipedia is not always the most accurate, but my explanation roughly matches theirs.
Yes, spotless or almost, but the temperatures don’t go really down. Strange no ?
Ray (14:50:09) :
Leif, what is your take on what they call faculae regions (FR)?
The Australians have an interesting explanation… http://www.sydneyobservatory.com.au/blog/?p=2260
… and they seems to say that there was a very small sunspot (very hard to see through) this week.
The Australian comments are good. However, there is nothing new about FRs. There were first described by Schreiner in 1625. FR develop before a spot [or two spots] are seen and lasts after they have disappeared. The FR are basically lower-magnitude magnetic areas that therefore appear bright. It has been known for centuries now that sunspots are formed by coalescence of small pores and specks. This knowledge was somehow forgotten in the 1960s, possibly because of the widespread acceptance of Babcock’s idea of a thick, strong ‘flux rope’ erupting from below and arching up, spots forming at the exit and entry points. People also stopped looking at the Sun for hours to follow the development of spots, and rather relied of snapshot photographs. With the advent of movies of spot development constructed from continuous spacecraft observations, people have rediscovered the coalescence aspect. See the movie here: http://revver.com/video/404550/hinode-lower/ and the discussion here: http://heliophysics.org/headlines/y2007/4review_trilobite.htm
So, it is possible that many spots will not develop and solar activity will mainly be in form of FRs, if Livingston and Penn are correct.
Ray (11:47:07) :
Leif, what about the size of the sun? Does it change over time and are we able to measure it precisely?
In the sky the diameter of the Sun is about half a degree [same as that of the Moon]. That translates to 1,392,000 km or 866,000 miles. It does change with time [it is getting larger] but VERY slowly, millions of years to see any real change. Whether it changes on a short time scale, like days or years, is hotly debated, and there is a satellite PICARD dedicated to measuring the diameter of the Sun. Because the Sun is a rotating ball of gas with a magnetic field that creates hills and vales, the notions of a single ‘size’ is somewhat fuzzy, see: http://news.softpedia.com/news/Sun-039-s-Sphere-Is-Not-Perfect-94896.shtml
Leif Svalgaard (18:46:40) :
What I have in mind is somewhat of a kind of “breathing” of the sun. You can see a very good example (to the extreme) with the recent discovery of the cyclic swelling and contaction of Betelgeuse. That cycle must also be regulated by internal mechanisms. But it could be possible that the expention and contraction could also influence our climate.
Leif Svalgaard (18:36:08) :
Thanks! That was very interesting and informative. As they say, let’s not forget the discoveries of the past so not to think that we are the first one to discover them. For one thing, an considering the limited tools they had in the past, those people had a very good sense of observation, deduction, logic and imagination.
Ray (21:14:47) :
That cycle must also be regulated by internal mechanisms. But it could be possible that the expention and contraction could also influence our climate.
Some stars have an internal constitution that supports large-scale pulsations. Other stars – including the Sun – are stable against such pulsations, so the Sun does not pulsate. There are about a million random ‘ringings’ of the Sun [the 5-minute oscillations] but they do not cause systematic, overall radial pulsations. There might be some undiscovered flows inside the Sun that could cause variations in size [and that is why we are looking for them] and they would be of importance for TSI, but none have been found [yet] that are generally accepted [although there are many claims], so any changes must be very small.
Leif Svalgaard (22:28:16) :
Thanks Leif.
So when I we sending a probe crashing through the sun? Such probe could mabe be protected by a strong magnetic shield in order to get there first.
I believe that Picard and his assistants found a size change in the Solar diameter that really defies the expected range due to orbital distance. Neither proved nor disproved, as was the Maunder until several research efforts were conducted. He was able to keep time in an accurate manner only improved upon with the invention of the atomic clock, and he used that timing to measure transit of sun & features.
Such an event, dilation or expansion of the Sun beyond expected minima range AND orbital range lies as an unproved possibility in view of modern assumptions.
A dozen or so record low maximum temps yesterday across the N. portion of California.
The low pressure cell was a cutoff low, coming across the Pacific, not from Gulf of Alaska.
Ray (07:56:08) :
So when I we sending a probe crashing through the sun? Such probe could mabe be protected by a strong magnetic shield in order to get there first.
A magnetic shield would not protect against the fiery power of solar photons.
rbateman (07:58:34) :
I believe that Picard and his assistants found a size change in the Solar diameter
The ‘seismic’ radius of the Sun varies with the solar cycle:
http://arxiv.org/PS_cache/arxiv/pdf/0902/0902.1002v1.pdf
But is probably the result of solar conditions [magnetic field, density, etc] along the path of the ‘helioseismic’ waves from the backside of the Sun, and the seismic radius is not the same as the ‘visible’ radius. PICARD might clear all his up or at least tell us what questions to ask. BTW, note the annual variation of the seismic radius seen in Figure 3. This is, of course, an artifact of the data and the analysis method.
Leif Svalgaard (10:04:28) :
It was not abundantly clear from what I read that it was resolved. One of those things that left it hanging in midair. Someday we might get a surprise, but unless we enter a similar period and actually witness it happening again, for our purposes it didn’t happen. At the time, along with the extended dearth or visible solar activity, nobody knew anything was amiss. How could they?
To Picard’s credit, he did manage some very precise and way ahead of his time measurements of the planets and transits. Who knows?
With MDI, EIT and Hinode offline, our eyes in space are getting very limited.
How long are bakeouts supposed to take?
3.5 hrs in the oven is what I do for my CCD camera dessicant.
Most likely more involved in space.
Still, we’re rather blind here.
Leif Svalgaard (09:52:36) :
Ray (07:56:08) :
So when I we sending a probe crashing through the sun? Such probe could mabe be protected by a strong magnetic shield in order to get there first.
A magnetic shield would not protect against the fiery power of solar photons.
————–
What could protect such a probe? Something like the methaphasic shield used by Dr. Crusher in STNG maybe?
Looks like SOHO is back online. The latest image of a blank sun has been posted…
LOL 🙂
Ray (13:30:18) :
What could protect such a probe? Something like the methaphasic shield used by Dr. Crusher in STNG maybe?
Just a simple heat shield [umbrella] in front of the spacecraft. The spacecraft would fly in the shadow of the shield. Although the corona is millions of degrees hot, it is so thin that there is almost no heat in it, so in the shade it would be very cold. We would have to heat the spacecraft artificially even as it plunges into the Sun.
Leif Svalgaard (14:43:00) :
You saw Sunshine, too, didn’t you? LOL
http://www.imdb.com/title/tt0448134/
Yup, SOHO MDI Continuum back up. Now we’re cooking 🙂
A few notes about SOHO-MDI.
MDI is still offline. The onboard processor was disrupted on the 28th.
We do not know the cause. But reloading the software fixed the
problem. We had some further problems reloading and testing
the observing sequences this past week but are not able to test
the loads due to the very limited telemetry now. SOHO is in one
of the times of limited telemetry caused by the limited motion
of its antenna (2-3 weeks each 90 days since 2003).
We will start getting enough high-rate
telemetry around Aug 18-20 to do proper diagnosis. We have decided
to wait until then to restart normal operations. The very few images
on the 8th were part of the limited diagnostics. Do not expect further
MDI high rate (full disk continuum or magnetograms) until after
the 18th or 20th. We are presently getting low-rate data which is
needed for the farside images – but they are very very likely to continue
to be very boring. And without the MDI magnetograms we would need
to mess with the automatic processing to include GONG or SOLIS
magnetograms for the frontside. I am too busy to do that for only a week
so do not expect any MDI farside images until after the 20th either.
On a different topic, we are anticipating the launch of SDO in December
with the HMI instrumet which has a 4kx4k imager vs MDI 1kx1k.
And SDO will have continuous telemetry so there will be a LOT more
data. MDI data is a subset of HMI so we will stop MDI after an
overlap with HMI. We would like to see a quiet Sun to start HMI
helioseismic studies so are pleased that the Sun is patient with
the SDO launch schedule.