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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Invariant (15:49:53) “The deviation between this curve and the real temperature is largest in 1910 and in 1940.”
It is unfortunate that we do not have AM (angular momentum) records (for Earth’s shells) going back that far. Fortunately EOP (Earth Orientation Parameter), SOI, NAO, PDO, AMO, & other records give hefty clues about the interval bracketed by those dates.
Also – Invariant, regarding ~1910-1940:
See figure 3 here:
Mursula, K.; & Zieger, B. (2001). Long-term north-south asymmetry in solar wind speed inferred from geomagnetic activity: A new type of century-scale solar oscillation? Geophysical Research Letters 28(1), 95-98.
http://spaceweb.oulu.fi/~kalevi/publications/MursulaAndZieger2001.pdf
Suggestion:
1. Cut/paste figure 3 – middle panel – into an image editor (like ‘Paint’).
2. Stack it upon itself several times (remember 0=360 – i.e. december becomes january).
(You will see striking patterns many might have little hope of noticing without step#2. Stacking empowers one to ‘spin the cylinder’ (so to speak) and thus overcome any helical/dimensional-visualization challenges.)
If your mind is open, see the works of Ivanka Charvatova and note that 1931 is dead-centre in the “trefoil” window of 1906-1956. Caution: Many here focus on the sun without considering the celestial bodies at the other end of solar-terrestrial relations, which are also influenced by solar system dynamics in ways which are not (even remotely perhaps) fully understood. (Watch out for those who do not tell the whole truth.)
http://www.sfu.ca/~plv/(J,N)o2&Pr.png
http://www.sfu.ca/~plv/ChandlerPeriod.PNG
http://www.sfu.ca/~plv/1931UniquePhaseHarmonics.png
http://www.sfu.ca/~plv/LODaa(yoy)diffsqHadSST.PNG
http://www.sfu.ca/~plv/CCaa1mo&11aT1mo.PNG
Suggested:
Explore how the ENSO activity around 1940 played out in temperature records in different parts of the world — maybe use the following site since it is so fast since you just click on locations on the map to rapidly access nearby station records which are then graphed in just one more click:
http://data.giss.nasa.gov/gistemp/station_data/
As Currie (1996) has cautioned us, global averages can be blinding.
Currie, R.G. (1996). Variance contribution of luni-solar (Mn) and solar cycle (Sc) signals to climate data. International Journal of Climatology 16(12), 1343-1364.
~1940 is a brilliant example.
maksimovich 11:43:52
And yet, it varies.
===========
maksimovich (11:43:52) :
“Lockwood is a coauthor of Rouillard et al (2007) and so agrees with us.”
THE RISE AND FALL OF OPEN SOLAR FLUX DURING THE CURRENT GRAND SOLAR MAXIMUM
Is irrelevant, because what I plot are the HMF B values that Rouillard [and Lockwood] sent us. The remaining sticking point is that we disagree on the solar wind speed increase since 1880. We think it is an artifact and Lockwood does not. That influences his calculation of the radial component, but has no influence on the magnitude of the field, on which we totally agree.
rbateman (14:02:16) :
Leif, do you wish to enter into speculation on this?
I think I just did. I give it 25% chance of being correct.
Paul Vaughan (17:57:02) :
(Watch out for those who do not tell the whole truth.)
Watch out for those who claim to know the whole truth
rbateman (10:30:02) “If we start tip-toeing around the tulips for fear of being speculative or upsetting the apple cart, then we shall surely bury any science beyond, and put it out of reach of discovery.”
Wise words.
Leif Svalgaard (20:40:38)
“Is irrelevant, because what I plot are the HMF B values that Rouillard [and Lockwood] sent us. The remaining sticking point is that we disagree on the solar wind speed increase since 1880. We think it is an artifact and Lockwood does not. That influences his calculation of the radial component, but has no influence on the magnitude of the field, on which we totally agree.”
Lockwood et al.(2009)
“Svalgaard and Cliver (2007b) propose that there is a minimum “floor” value to the
IMF strength B of 4.6 nT in annual mean data and a minimum to the open solar flux of 4×1014 Wb. We note that the observed annual mean of B for 2008 has already fallen to 4.2nT in the current solar minimum, but we do here find that the value of B has indeed been above 4nT at all times since 1905. McCracken (2007) proposes that the concept of floors in B may indeed be valid, but notes that since 1428 there must have been at least 4 upward steps in such a floor to reach present day values, the floor value for 1428-1528 being less than a tenth of today’s value. If the minimum B does change in discrete steps, as opposed to continuously, the reasons for this are not yet understood”
Is this merely a Gestalt effect by two different sets of observers? or is there some defined mechanism (constraint) for a “floor” in B?
maksimovich (23:00:06) :
but we do here find that the value of B has indeed been above 4nT at all times since 1905.
So the floor is 4 nT. The difference with our 4.6 is not significant and with more station data we all can get a better value.
McCracken (2007) proposes that the concept of floors in B may indeed be valid, but notes that since 1428 there must have been at least 4 upward steps in such a floor to reach present day values, the floor value for 1428-1528 being less than a tenth of today’s value.
McCracken’s calibration is off in 1947; http://www.leif.org/research/Comment%20on%20McCracken.pdf
and that feeds into his calibration for earlier times too.
is there some defined mechanism (constraint) for a “floor” in B?
There is evidence that the magnetic field needed on the sun to power the solar wind is 600 kW/Wb [see http://www.leif.org/EOS/592877.pdf ]. Since the solar wind must have a minimum speed to escape from the Sun [namely 254 km/sec = escape velocity at the height where the solar wind escapes (not the surface)], there must also be a minimum B corresponding to that [the floor]. If B falls below that there will be no solar wind. So, if there is a solar wind at all, B must at least have the value needed to give the wind a speed of 254 km/sec.
Leif Svalgaard (23:41:27) :
There is evidence that the magnetic field needed on the sun to power the solar wind is 600 kW/Wb
This was clumsily expressed. Better would be: Each Weber of magnetic flux delivers 600 kW of power into the solar wind. Enough power must be delivered to make the speed higher than the escape velocity [254 km/s], hence the flux has a lower limit [the floor], below which there will be no solar wind.
maksimovich (23:00:06) :
McCracken (2007) proposes […] the floor value for 1428-1528 being less than a tenth of today’s value.
The very low values of HMF B that McCracken derives at times are due to contamination from volcanic eruptions that delivers sulfuric acid aerosols to the atmosphere which in turn influences the 10Be deposition. A very clear example of this can be seen here:
http://www.leif.org/research/TSI%20From%20McCracken%20HMF.pdf
On page two, note the very deep dip at the time of the Krakatoa eruption in 1883. McCracken deduces an HMF as low as almost 1 nT, while the geomagnetic evidence is that B at that time was about 6 nT. Other significant dips similarly coincide with volcanic eruptions, e.g. Tambora in 1815.
maksimovich (23:00:06) :
is there some defined mechanism (constraint) for a “floor” in B?
Much [most?] of Lockwood’s and our ruminations about what is going on is just speculation [on both parts]. What is not speculation, but hard data agreed upon is the HMF B shown on slide 12 of
http://www.leif.org/research/AGU%20Fall%202008%20SH24A-01.pdf
This is a strong observational constraint of present and future speculation.
Leif Svalgaard (23:55:20)(and others)
Thanks for the references
“On page two, note the very deep dip at the time of the Krakatoa eruption in 1883. McCracken deduces an HMF as low as almost 1 nT, while the geomagnetic evidence is that B at that time was about 6 nT. Other significant dips similarly coincide with volcanic eruptions, e.g. Tambora in 1815.”
Coincidentally I was overlaying the singularities (vei) and cane to similar conclusions with the transport problem (due to the changes in the chemical composition of the polar atmosphere and the polar vortex) eg Stenchikov et al 2002
Hence one needs to know the state of the atmospheric composition as the instrumental recorders (ice for 10be) and the biological instruments (for 14c ) often have competing influences.
eg uv
http://www.aslo.org/lo/toc/vol_24/issue_6/1117.pdf
(also a small problem for temp reconstructions)
Ok now for some interesting problems .
http://i255.photobucket.com/albums/hh133/mataraka/GCRmodulation.jpg
Red series near earth measurements,blue voyager 1,green voyager 2.
Horizontal bars we observe stationery behavior,and then step like behavior.
maksimovich (02:54:35) :
Horizontal bars we observe stationery behavior,and then step like behavior.
The steps may be just coincidences. What is more interesting is the delay as we go from Earth, to V2 to V1, showing that the modulation takes place in a large volume surrounding the probe, rather than only at the heliopause.
Are there six solar cycles per cycle of the PDO and if so how far back can we show that. If it is so, can that be only co-incidence?
==================================
Leif Svalgaard (08:45:54): (in response to sunspots disappearing)
Which is irrelevant, because they will still be clearly visible in the UV [e.g. Ca II K-line] or in magnetograms, so are still there.
If I misinterpreted this and the discussion leading up to it, I apologize. You indicated that your prediction is equivalently in terms of flux or SSN (which makes sense). The above statement seems to indicate that even if the visible sunspots do not show up – which some would take as a miss on the SSN prediction – they are still there, just with reduced contrast. This seems to indicate you still feel that sunspots (albeit invisible ones) are still a good proxy for flux.
My eye is by no means calibrated, but to me the magnetograms and visible sunspots have been in concert during this minimum (don’t know about the UV). I have not noticed what looks to be a sunspot area in the magnetograms that does not show up visibly. This would seem to indicate that L&P does not provide a complete explanation of the (possible) divergence between the 10.7 flux and sunspots. As you commented earlier, the 10.7cm flux has slowly started increasing (up to about 69 in August, I believe), yet SSN does not seem to be following.
Of course, it might be that I don’t know what I’m looking for. 🙂
I say blind squirrels generally starve first.
Leif Svalgaard (04:18:10)
“What is more interesting is the delay as we go from Earth, to V2 to V1, showing that the modulation takes place in a large volume surrounding the probe, rather than only at the heliopause.”
“The steps may be just coincidences”
1)Would not “clumpiness” in the iSM be expected in a rotating disc (an elliptic plane ) ?
2) Would the larger modulation volume (rather then changing boundary conditions at the heliopause and competition with the SW and ISM) suggest a secondary modulating mechanism (a physical mechanism) and would we not be able to observe the mechanism(s) visually ?
Ryan O (08:55:21) :
The UV (EIT imager aboard SOHO) would appear to be marching in lockstep with the L&P fade.
I have taken to presenting a composite image timeline to show the fading:
http://www.robertb.darkhorizons.org/DeepSolarMin8.htm
and a fullsize daily image of the UV Sun:
http://www.robertb.darkhorizons.org/DeepSolarMin9.htm
I do not have the luxury of posting up the required full size images that highlight the lines of failed plages where sunspots should be (space on server).
Curiously, the tiny plages blink in & out in the same relative timespace as do the Tiny Tims, and you are correct, very few of them make the magnetograms.
If my assumption of what they represent is correct, there’s your quarry.
Paul Vaughan (12:59:43) : Are you working with a moving integral (sliding fixed-width integration-window) or a running integral (cumulative from a fixed-anchor-point at the beginning of the series)?
I can explain the equation in more detail. First I would like to point out that the current instant value of any quantity is irrelevant for the thermal energy stored in the oceans and in the air. For example I have seen arguments like the HMF B has doubled the last century which makes little sense. In order to explain the problem with such statements let us first acknowledge that our earth has a simple heat balance which is described by the first law of thermodynamics,
m•cp•dT/dt =Qin – Qout
http://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node129.html
Here Qin is heat added to our earth and Qout is heat dissipated in one way or another – energy can never disappear but it can be transformed into very subtle forms as Richard Feynman once pointed out. When Qin is larger than Qout the temperature T must increase. But this is an integrated effect – larger Qin does not affect temperature directly, you have to integrate Qin (and Qout) over some time to see that the temperature T change. For our earth the thermal mass (m•cp) is huge, so we have to wait a very long time to see that T change.
Let us now imagine that reduced HMF B leads to more clouds and thus reduced radiation from our sun. This will not instantly change the temperature here at all and certainly not the day temperature more than the night temperature. In order to calculate the temperature drop of the air and the oceans, we need to use the above heat balance equation. Let us assume that more clouds leads to reduced Qin. Then we must integrate the heat equation to calculate the temperature drop.
In my Matlab equation I have speculatively assumed that it is HMF B only that controls our temperature, so I came up with and equation where the numerical integral of HMF B is involved,
T_est = 0.007640*cumsum(HMF_B-5.7848)-0.4470;
The reason I integrate HMF B all the way from the start is that energy cannot disappear. If HMF B really has an impact on our climate, our earth remembers, for example, that it was heated during solar cycle 22 and 23 – the temperature is, just like energy, a cumulative phenomenon. Please read Richard Feynman.
http://www.phy.davidson.edu/FacHome/swp/courses/PHY110/Feynman.html
Invariant (15:01:59) :
our earth remembers, for example, that it was heated during solar cycle 22 and 23 – the temperature is, just like energy, a cumulative phenomenon.
When you heat something it becomes hotter and radiates more, hence cools again [unless you keep heating it]…
Ryan O (08:55:21) :
but to me the magnetograms and visible sunspots have been in concert during this minimum (don’t know about the UV). I have not noticed what looks to be a sunspot area in the magnetograms that does not show up visibly.
They have both been tiny [and we are not quite to the point where spots would be invisible [if ever]. It is too early to draw wide conclusions on this, but basically a full-blown L&P effect would show plages without spots. This is all to be seen in due time.
gary gulrud (09:22:27) :
I say blind squirrels generally starve first.
As usual, you make no worthwhile contribution.
maksimovich (12:30:59) :
1)Would not “clumpiness” in the iSM be expected in a rotating disc (an elliptic plane ) ?
2) Would the larger modulation volume (rather then changing boundary conditions at the heliopause and competition with the SW and ISM) suggest a secondary modulating mechanism […]
The standard [textbook] argument goes like this:
Interstellar variations of the flux can be of two kinds: (1) The Earth could pass through static cosmic ray variations [clumps or clouds] in its motion, or dynamical CR variations [e.g. shock waves from supernovae]. The near-isotropy of CRs implies diffusive transport in the galactic magnetic field. Consider now, a fluctuation in the CR density of length scale L. It would have a life-time T of the order L^2/k, where k is the CR diffusion coefficient. If the solar system is moving at speed V, it will take a time L/V to cross the clump. Therefore, we require L^2/k >> L/V for modulation. Setting V = 10 km/s and k = 1/3Pc [c=speed of light], the diffusion mean free path P mut be at least greater than several CR gyro-radii in a galactic field of a few microGauss. One finds that L >> 3E17 cm, which would be traversed in time T = 100,000 years or more, so it is not likely that CR intensity variations observed at Earth on time scales less than 100,000 years can be produced by the solar system passing through clumps or clouds. A simple way of seeing the same is to note that cosmic rays move very fast compared to the speed of the solar system.
Invariant (15:01:59) “[…] I integrate HMF B all the way from the start […]”
This confirms what I suspected after seeing “cumsum” in your post at Invariant (16:05:25).
Thank you for sharing interesting comments.
Invariant (15:01:59) :
“…our earth remembers, for example, that it was heated during solar cycle 22 and 23 – the temperature is, just like energy, a cumulative phenomenon. Please read Richard Feynman.”
Reply:
I think your dead right and therefore temperature is not a good diagnostic of total energy over the short-term as there are many inter-linked processes that use the energy in our chaotic climate system in different ways. Some energy is being radiated into space quickly, some becomes trapped over long time periods and some is permanently retained as a result of chemical processes.
To really understand what is happening our climate we need to be able to measure the earths energy balance dynamcally. We also need to have the same understanding of solar processes, so we can understand how the earths prime climate driver changes over time and make meaningful climate forecasts.
Leif Svalgaard (21:47:00) :
“The standard [textbook] argument goes like this”
Sorry, we are at tangents (due to incompleteness on my part)
I was suggesting that changes in the density of the ISM (not the passage through shells etc) can be expected on shorter timescales 10^3-10^5 years eg Muller et al.
This effects the boundary conditions of the heliopause,and the subsequent modulation.
Leif Svalgaard (21:09:57) : When you heat something it becomes hotter and radiates more, hence cools again [unless you keep heating it]…
Right. This would mean that Qout in the heat balance may be a function of temperature as well [as Qin]. Reflecting a little about what is going on in this equation,
m•cp•dT/dt = Qin – Qout
we may argue that increased cloud coverage may lead to reduced Qin, but possibly also to reduced Qout since more clouds may have an insulating effect. In addition we may argue that clouds can evaporate too, meaning that both strong HMF B and TSI can lead to reduced cloud coverage. Increased TSI by itself may lead to increased Qin too, and we may suspect that there are a number of such temperature dependent, nonlinear and nontrivial feedback mechanisms like evaporation from the oceans that may simultaneously affect Qin and Qout.