It has been awhile since I’ve looked at the Ap Index. The last time was April of 2009.
From the data provided by NOAA’s Space Weather Prediction Center (SWPC) you can see just how little Ap magnetic activity there has been since. Here’s my graph from September 2009 SWPC Ap data:
For a longer perspective, David Archibald, has a graph of the Ap Index back to 1932. The solar average geomagnetic planetary index, in Dec 2008, Ap was at its lowest level in 75 years:
Click for a larger image – I’ve added some annotation to the graph provided by Archibald to point out areas of interest and to clarify some aspects of it for the novice reader.
The last time the Ap index was this low was 1933. The December 2008 Ap value of 2,, has never been this low. (Note: Leif Svalgaard contends this value is erroneous, and that 4.2 is the correct value – either way, it is still lower than 1933) Further, the trend from October 2005 continues to remain low, though some signs of a slight rebound are showing.
This Ap index is a proxy that tells us that the sun is now quite inactive, and the other indices of sunspot index and 10.7 radio flux also confirm this. The sun is in a full blown funk, and your guess is as good as mine as to when it might pull out of it. So far, predictions by NOAA’s SWPC and NASA’s Hathaway have not been near the reality that is being measured.
As Leif Svalgaard points out, Ap is just one of several indices that describe geomagnetic activity. There are several others [aa, am, IHV, …] that go much further back in time [to the 1840s]. You can get more info from:
http://www.leif.org/research/IAGA2008LS.pdf and
http://www.leif.org/research/Seminar-UCLA-ESS288.pdf
For those that follow the sunspot number (SSN) I’ve graphed the Ap and SSN together. As you can see, we’ve been in a reduced state of solar activity now for quite some time. It has been almost 4 years since the prominent drop in Ap in October 2005. SSN mirrors the decline of the Ap index since then.
As many regular readers know, I’ve pointed out several times the incident of the abrupt and sustained lowering of the Ap Index which occurred in October 2005. The abrupt step change seemed (to me) to be out of place with the data, and since then the data seems less “active”, with reduced amplitudes. And then we have the fact that the sun seems to have reestablished at a lower plateau of the Ap index after that October 2005 step change and has not recovered now in almost 4 years. It seems to me to be a noteworthy event.
UPDATE: Thanks to Leif Svalgaard, we have a more extensive and “official” Ap dataset (NOAA’s SWPC has issues, see comments) that I’ve plotted below. The step change in October 2005 is still visible and the value of 3.9 that occurred in April of this year is the lowest for the entire dataset.
And I’ve also plotted the 1991 to present data from BGS/Svalgaard to compare against the NOAA SWPC data:
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I don’t know Anthony….with your well established influence on sunspots, writing something like “The sun is in a full blown funk, and your guess is as good as mine as to when it might pull out of it,” might be enough to bring us to solar maximum tomorrow.
Which scientists was it a while back reported here being confident that subsurface something-or-other showed that the Sun was getting ready to burst forth out of its slumber? If they can be coaxed out from under their beds, it might be interesting to hear how their readings are doing now.
I alternate between exasperation and pity towards the solar scientists these days (and for the last year, really). On the one hand, I sometimes want to yell “maybe given how utterly wrong you’ve been you ought to just stfu with the predictions until you’ve really got something solid”. Otoh, welcome to the scientific method, and appreciate that at least these are predictions that can be tested in the near term, however bright red faces get at the results, rather than after pension and retirement have been safely achieved, ala the climatologists.
I have so many questions, and so few answers. As our Sun’s magnetic pulse decreases, does the the ability of our Sun in deflecting incoming Milky Way cosmic rays decrease? Do higher Earth atmospheric cosmic ray amounts really seed more low clouds? Do more low clouds cool the Earth? What are the exact physics and chemistry within our Sun that is actually causing the decreased energy output? During solar minimums, do our ocean temperatures also decrease? Could changing ocean temperatures change jet stream patterns? Could changing jet streams move air masses that result in years of weather changes that create climate change? Is the science of climate change really completely understood? Is it prudent to tax CO2 emissions trillions of dollars when so many questions are left unanswered? Can science really discuss and modify climate change theories openly without the threat of billions of dollars of research money being taken away? I am dazed and confused, please enlighten me.
Point of clarification, please: Is the Ap Index what is shown on your dashboard — and at fascinating solarcycle24.com site — as A-Index?
Craig
Mad dogs & Englishmen.
We can thank our lucky star for showing us who is boss when it comes to actual climate change. This solar minimum reminds mankind that we are tiny little players living in a variable universe.
Common sense is shouting from the rooftop telescopes people.
We are in for some nasty weather. Our climate will do what it has been observed doing in the past. Lower solar activity means less life giving warmth on the planet.
And know one can tell you when the sun will decide to warm back up. This solar inactivity could last decades. Decades of bitter cold weather does not sound like a warm climate to me.
Think about little ice ages as if they were an Atlantic hurricane. Are we or are we not in the warning cone of prediction? We know ice ages come & go. They will come again. We may be entering one now as we are certainly not warming.
And yet we are a senate vote away from further rationing of our energy supply. The very energy supply that allows us to warm our bones and enlighten our lives.
Is it possible to know the approximate Ap index during the LIA, perhaps based on proxies?
Is ‘radio flux’ same as ‘solar flux’?
Is ‘SSN’ same as ‘Wolf’ number?
If 1934 was one of the hottest and driest years, is there a disconnect with low Ap index in 1933/34?
Leif,
– I read that L&P do three measurements: of temperature, magnetic splitting and continuum brightness. How can they have a “continuous” spectrum if they have to look to a place in the photosphere which is by definition a spectrum with absorption lines?
– L&P write in “Sunspots today: a Cheshire Cat”, p. 2, “Yet all new cycle number 24 spots that we have observed have been tiny “pores” without penumbrae (e.g. Figure 1). I suppose some cycle 24 sunspots had a penumbra?
– Possibly it is normal that during a solar minimum we see only small sunspots. Am I right?
– What do L&P mean when they conclude in the same paper : “there is not a unique relation between sunspot brightness and magnetic field”? Looking at the figure (3), I see a clear relation between both: a higher sunspot brightness corresponds with a lower magnetic field.
– Is the following interpretation correct? “When the sun’s activity diminishes, (from solar max to solar minimum) it is normal that: 1) the magnetic field of the sunspots diminishes; 2) thus that the temperature of the umbrae rises.”
– Is this statement right: “Large sunspots have a large magnetic field, small ones have a small magnetic field.”? Is there any relation between both?
So I have a lot of questions. I presume the unusual behaviour of the sun stimulates us to a more profound study. Thanks!
(Maria again bounds across the hilltop and sings) “The Sun’s alive, with the sound of music…”
Anthony
There appears to be a similar, but not as stark, step change around month 40. The period that followed did not get as quiet but it is quite similar otherwise. If we use that as a model, then I would expect the Sun’s magnetic activity might have hit bottom last December (about 35 months after the downward step change. Maybe the Sun has a 14 year cycle that you have just discovered?
Bill
I keep reading your articles and see your reference to David Archibald, Leif Svalgaard, Roger Pielke Sr. and Jr. as well as others and would like to know more about these men. Any chance you could bring many of us novices up to speed?
[Reply: use the search function to find articles by those individuals. ~dbstealey, moderator.]
Sorry for the math error, 175 (step change in ’05) minus 40 (previous step change) is only 135 months, which is 11 1/4 years, right in line with the typical solar cycles.
Minor nits:
“some sings of a slight rebound are showing.”
“the sun seems so have reestablished”
REPLY: fixed thanks, wrote this in the wee hours of the morning during a bout of insomnia. Spell checker didn’t cath those. – A
minor typos
“though some sings of a slight rebound”, signs I’m sure
“he sun seems so have reestablished”, to I’m sure
So, do you think the October 2005 step change was some sort of sensor malfunction or recalibration?
Meanwhile Catlin has tapped WWF for cash to speed up ‘analysis’ of the data in time for Copenhagen. Why bother when we all know what that data will ‘reveal’?
http://www.catlinarcticsurvey.com/
“Fresh Arctic evidence for climate summit
Posted by Dominic Hilton
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Wednesday, 12 Aug 2009 00:00
Scientists are busy analysing data from the Catlin Arctic Survey. The data will provide important new evidence for the crucial climate negotiations in Copenhagen this December.
The Catlin Arctic Survey team returned this May with unique new measurements of the thickness and extent of sea ice in the Arctic. The University of Cambridge’s Polar Oceans Physics Group is currently analysing the data, with initial results already suggesting that the sea ice is newer and thinner (and therefore more liable to melt) than expected. The results will help climate scientists around the world to understand how quickly the dwindling summer sea ice will melt and to predict more accurately the effect this will have on the global climate.
WWF are providing funding to help the research team speed up their analysis. It’s crucial that the results are available in time for the UN climate change summit in Copenhagen, as they will strengthen WWF’s calls for a strong global climate deal. Governments must take action urgently to keep global temperature rise below 2°C, the threshold beyond which most scientists predict climate change could become catastrophic.
“Climate change is happening now and nowhere is it more evident than in the Arctic,” said WWF’s head of climate change, Keith Allott.
“Sea ice is a critical part of Earth’s climate system and the loss of sea ice in the Arctic Ocean is happening decades ahead of most predictions. We cannot predict all of the effects of this ice loss, but scientists foresee severe disruption to the natural world on both a local and a global scale.””
What what does it all mean?
As a skeptic layman I was that thinking low sun activityi will drive some significant cooling.
But it does not seem that this summer was cooler than usual globally. Does it mean that the cosmic-rays – cliemate theory is not so solid?
Or maybe there is supposed a lag between low sun actitivity and lower temps and we will see the effect in the coming months?
“NaperBoy (08:26:09) :
If 1934 was one of the hottest and driest years, is there a disconnect with low Ap index in 1933/34?”
I assume that because this drop was very quick and did not last long it had little effect.
Also it was one of the hottest for the USA, not the world.
I am suspicious of the link to the 70s cooling in the above graph though. What is interesting is that if the Ap Index indicates a weak cycle 24 maximum then that’s when things could get interesting.
The funny thing is that just 5 years ago many were talking about how recent sunspot activity was the most active in 1000 years; 5 years down the line things have changed completely.
It just proves how unpredictable the sun is and that one can only speculate as to what may happen in the future.
The SWPC values of Ap are not correct. There are two problems: 1) the values for each day are not the ‘official’ values, and 2) the monthly means are truncated rather than rounded, so the ‘2’ for December 2008 was really ‘2.9’ and should have been rounded to ‘3’.
The official values for Ap are provided by GeoForschungsZentrum (GFZ) Potsdam, Adolf-Schmidt-Observatorium für Geomagnetismus, Niemegk, Germany on behalf of the International Service of Geomagnetic Indices (ISGI) of the International Association of Geomagnetism and Aeronomy (IAGA).
Below is a table for comparison. The first value is the official Ap, the second value I’ll discuss below, and the third value [without decimal point] is the SWPC truncated value:
2008 1 7.8 9.6 6
2008 2 11.0 12.2 9
2008 3 11.1 11.2 10
2008 4 9.2 9.3 9
2008 5 6.3 7.0 6
2008 6 6.7 8.0 7
2008 7 5.4 6.3 6
2008 8 5.0 5.3 5
2008 9 5.6 5.6 5
2008 10 6.5 6.9 6
2008 11 4.2 5.0 3
2008 12 4.5 5.8 2
2009 1 4.3 5.3 3
2009 2 4.5 5.0 4
2009 3 5.3 5.3 4
2009 4 4.4 4.4 4
2009 5 3.9 4.3 4
2009 6 4.1 4.9 5
2009 7 4.4 5.1 5
2009 8 4.6 4.9 5
Now for the second value: There is a semiannual modulation of Ap due to the geometry of the interaction between the Sun and the Earth. At the solstices, the interaction is reduced and Ap is reduced about 20%, so if one wants to use Ap as an indicator of solar activity, this reduction must be corrected for. That is the second column. So, in December 2008, Ap was not 2, but rather 5.8.
I am new to your web site, and find it very interesting. I am aware that you are a controversial figure with many in the AGW community, but apart from a few moans here and there, I have been very pleased by how much balance you show. Until this. I read this review of one of Archibald’s publications, checked on some of the issues raised and the complaints seem substantive. http://n3xus6.blogspot.com/2007/02/dd.html
Here is my compliant. You do a great job on this web site, but that depends on your credibility. There are many credible scientists out here whose research is soundly based, fully peer reviewed, and will still support your viewpoint. Avoid the specious, otherwise it gives the informed justified reason to question anything and everything you publish…. and from what I have seen so far that is not justified; as for the uninformed, don’t we all have an obligation to direct them to the best and most credible research? This one is wide off the mark… even if this particular article is true… with Archibald you can not accept anything without checking everything he does.
Rik Gheysens (08:26:23) :
How can they have a “continuous” spectrum if they have to look to a place in the photosphere which is by definition a spectrum with absorption lines?
Between the lines there is the ‘continuum’
I suppose some cycle 24 sunspots had a penumbra?
– Possibly it is normal that during a solar minimum we see only small sunspots. Am I right?
Here are all the spots of SC24 so far: click
Some of the larger spots have both penumbra and umbra.
And there can be large spots at solar minimum. E.g. at the last minumum: ftp://howard.astro.ucla.edu/pub/obs/drawings/1996/dr961124.gif
– What do L&P mean when they conclude in the same paper : “there is not a unique relation between sunspot brightness and magnetic field”?
Just covering their backside. There is a good correlation.
“When the sun’s activity diminishes, (from solar max to solar minimum) it is normal that: 1) the magnetic field of the sunspots diminishes; 2) thus that the temperature of the umbrae rises.”
Not in general, but it is something one has to look more careful at now.
– Is this statement right: “Large sunspots have a large magnetic field, small ones have a small magnetic field.”? Is there any relation between both?
Yes, this is generally true: larger spots, stronger field.
David Kitchen (10:27:30) :
with Archibald you can not accept anything without checking everything he does.
That is true with most things on the internet, and as you point out, in particular with Archibald’s stuff.
David Kitchen (10:27:30) : This site posts a number of articles that might not otherwise see the light of day . Those that are specious or spurious (insert any other word for false , if you choose) usually get caught out in a hurry . This in itself makes WUWT worth reading .
The weather over land is far more influenced by the oceans than any other heating/cooling mechanism. Anyone thinking otherwise needs to live on the west coast of any larger land body for at least a year and study daily weather charts.
But it does not seem that this summer was cooler than usual globally. Does it mean that the cosmic-rays – cliemate theory is not so solid?
Or maybe there is supposed a lag between low sun actitivity and lower temps and we will see the effect in the coming months?
I have read studies that put the lag at 3-12 years. This is because the oceans hold much heat (correct me if I’m wrong, but something like 400x the heat content of air) that it takes a while for warming/cooling to manifest itself in warmer/cooler air temps.
Ocean temp is a much better indicator of global temperature than air temps.
[sorry, be more respectful or go post elsewhere] ~ ctm