Here are some highlights of these two new papers published in Physics Letters A by :
- Central Pacific region temperature dataset SST3.4 from 1990 to 2014 is studied.
- SST3.4 contains a sustained signal at 1.0 cycle/yr implying solar forcing.
- SST3.4 also contains a signal (<1 cycle/yr) showing El Niño/La Niña effects.
- This signal contains segments of period 2 or 3 years, phase locked to the annual.
- A 12-month moving average improves on a “climatology” filter in removing annual effects.
- Global ocean temperatures at depths 0–700 m and 0–2000 m from 1990 to 2014 are studied.
- The same phase-locked phenomena reported in Paper I are observed.
- El Niño/La Niña effects diffuse to the global oceans with a two month delay.
- Ocean heat content trends during phase-locked time segments are consistent with zero.
The papers, the link downloads the full PDF:
Paper 1 Abstract
Equatorial Pacific Ocean temperature time series data contain segments showing both a phase-locked annual signal and a phase-locked signal of period two years or three years, both locked to the annual solar cycle. Three such segments are observed between 1990 and 2014. It is asserted that these are caused by a solar forcing at a frequency of 1.0 cycle/yr. These periodic features are also found in global climate data (following paper). The analysis makes use of a twelve-month filter that cleanly separates seasonal effects from data. This is found to be significant for understanding the El Niño/La Niña phenomenon.
The Sun is the climate pacemaker I. Equatorial Pacific Ocean temperatures Physics Letters A; ©2014 Elsevier B.V.; doi:10.1016/j.physleta.2014.10.057
Conclusions and summary
Phase-locked sequences are found in Pacific Ocean SST3.4tem-perature data during the periods 1991–1999, 2002–2008 and in 2009–2013. These three sequences apparently being separated by climate shifts. It is asserted that the associated climate system is driven by a forcing of solar origin that has two manifestations: (1)A direct phase-locked response to what is identified as a solar forcing at a frequency of 1.0 cycle/yrfor the whole time series; (2)A phase-locked response at either the second or third sub-harmonic of the putative solar forcing between 1991 and 1999; 2001–02 and 2008; and again between 2008 and 2013.
This study confirms the results of [1]that some of the largest maxima/minima in the oscillations of the phase-locked state corre-spond to well-known El Niños/La Niñas. For example, the sequence 1996 La Niña – 1997/98 El Niño – 1999 La Niña corresponds to a minimum–maximum–minimum portion of phase-locked segment #9. The climate system is presently (June 2014) in a phase-locked state of periodicity 3 years. This state, which began in 2008, con-tains a maximum (El Niño) at about 2010 followed by a minimum (La Niña) followed by a maximum (weak El Niño at about 2013). If the climate system remains in this phase-locked state, the next maximum will not occur until about 2016 – i.e., no El Niño before that date. On the other hand, if a maximum occurs before then, it will signal the end of the phase-locked segment (and therefore a climate shift).
On its web site [15]the National Oceanic and Atmospheric Ad-ministration asks: “How often does La Niña occur?” Answer: “El Niño and La Niña occur on average every 3 to 5 years. However, the histori-cal record the interval between events has varied from 2 to 7 years. …” Our findings show that duringphase-locked time segments the period is either 2 or 3 years. If a longer interval is observed, this is notrepresentative of a variable ‘period,’ but indicates the occur-rence of a climate shift between phase-locked segments.
It is pointed out that the 12-month moving average filter is demonstrably superior to the climatology method of removing sea-sonal effects in data. This is seen to be the case for interpretation of El Niño/La Niña data, which contains spurious annual effects when treated under the climatology scheme.
An extension of these results to global data will be presented in a second Letter [16]. It will be shown that patterns of sub-harmonics identical to those described here occur throughout the oceans.
Paper 2 Abstract
In part I, equatorial Pacific Ocean temperature index SST3.4 was found to have segments during 1990–2014 showing a phase-locked annual signal and phase-locked signals of 2- or 3-year periods. Phase locking is to an inferred solar forcing of 1.0 cycle/yr. Here the study extends to the global ocean, from surface to 700 and 2000 m. The same phase-locking phenomena are found. The El Niño/La Niña effect diffuses into the world oceans with a delay of about two months.
The Sun is the climate pacemaker II. Global ocean temperatures Physics Letters A; ©2014 Elsevier B.V.; doi:10.1016/j.physleta.2014.10.058
Conclusions and summary
Global ocean temperature time series from the surface to depths of 2000m since the year 2000 are found to agree in detail with those of other diverse climate indices. It is asserted that these systems are driven by a forcing unquestionably of solar origin that has two manifestations: (1) a direct phase-locked response to what is identified as a solar forcing at a frequency of 1.0cycle/yrfor the whole time series; (2) a second phase-locked response at a period of two years or three years.
With these findings it is becoming clear that the entire cli-mate system is responding to the varying incident solar radiation, and is subject to interactions, most likely nonlinear, thatproduce the subharmonics of two or three year period, and is moreover evolving non-continuously, as evidenced by breaks in the pattern whose timing can be identified with known climate shifts. The most prominent manifestations of the pattern are found in the El Niño/La Niña phenomena. As emphasized in [2], the “natural” pe-riodicity of El Niño/La Niña is two or three years, and observations of longer intervals should be considered probable evidence for an intervening climate shift.
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Another mystery or something that I can not understand (Milankovitch Cycles aside) is why when glaciation gets along on it’s way (Younger Dryas for example) why it does not feed upon itself due to an increase in ice/snow cover hence greater albedo more reflectivity result colder temperatures. That however does not work because the climate never moves in the same direction for an indefinite period it always reverts back toward the mean no matter how far it strays from the mean.
I can not get my hands around this.
My understanding is that when orbit becomes more circular (or the axis less oblique), there is less seasonal variation. Winters may be mild, but the ice does not melt much in summer. That creates a positive feedback via albedo.
My comment at 8:56 am belongs here.
Okay, M. Painter, here ya go!
http://wattsupwiththat.com/2015/01/09/two-new-papers-suggest-solar-activity-is-a-climate-pacemaker/#comment-1838784
#(:))
(how in the world did I even find this? when I saw “mpainter” in the recent comments queue, I wanted to read what you wrote — your enthusiastic forthrightness is a joy to read… not here, as it turned out …. I mean when you have a deserving recipient of it, heh)
Thanks Janice,
I should have referred my comment to Salvatore’s observation at 9:31 am.
Good to know that someone likes my style…XXX
One last thought those who think(such as AGW theory) that one item is going to have a cause /effect on the vast climatic system are dead wrong.
This is not speculation.
The Sun will ; specifically our distance from it , as this article shows .
And the angle of the dangle (the Milliecycles).
And the much argued sun spot number is only a single proxy for aspects of solar activity and cosmic ray interference.
The sunspot number has an excellent correlation with all the other solar indicators, as the SSN goes, do go all the other.
However, the solar wind is out of phase with the sun spot proxies, and there is not better proxy for EUV rays than EUV rays. Among other things, cosmic rays are influence by interstellar dust, which is also a source of halides. Deposition of the 10be proxy in a locality correlates with precipitation some time after their creation in the atmosphere. Not all cosmic rays produce 10be, and so on.
Don’t know if we’ll solve the climate puzzle in our lifetimes, however, the approach by Douglass and Knox is a start.
The solar wind follows the same cycle as sunspots
http://www.leif.org/research/Solar-Wind-Climatology.png
The shape of the cycle is different, but quite reproducible from cycle to cycle.
The EUV follows the sunspot cycle very precisely:
http://www.leif.org/research/Reconstruction-of-Solar-EUV-Flux-1834-2014.pdf
http://www.leif.org/research/Rudolf%20Wolf%20Was%20Right.pdf
and the geomagnetic proxies for EUV are excellent.
It is true, however, that the cosmic ray proxies that we observe on Earth are not very well correlated with solar activity, although the cosmic rays themselves are.
Only in so far as your proxies themselves are concerned!
Equatorial coronal holes are better at short-term forecasting of the solar wind.
Only in so far as your proxies themselves are concerned!
Elaborate. As it stands, your comment is unintelligible…
Your EUV reconstruction is from 1834, however, the data set goes back to 1977.
It’s circular to point to a proxy reconstruction as validation of a proxy.
When the physics is understood, a proxy is inherently valid.
Thank you directing my attention to the Solar Full Disk EUV Flux at Earth presented in Reconstruction of Solar Extreme Ultraviolet Flux 1834–2014
The corrected data from 1996 to present does correlate EUV rays with the sunspot group numbers, however, it does so with a less than perfect correlation.
Apparently, the physics of the EUV/sunspot correlation is not as precise as measuring stationary temperature with a mercury thermometer, leaving much latitude in predicting EUV flux for the time period from 1834 through 1995.
An example: you measure the temperature with an ordinary mercury-filled thermometer. What you are really doing is using a proxy: the length of the mercury string rising in its glass enclosure. We know that mercury expands with increasing temperature, we know by how much, the physics is well-known and even if it weren’t we can still calibrate the thermometer [dipping it in melting ice water and boiling water], so the proxy [the length of the mercury string] is a perfectly valid measure of the temperature. Same thing with the EUV reconstruction [see http://www.leif.org/research/Reconstruction-of-Solar-EUV-Flux-1834-2014.pdf ]
So far I see solar cycle 24 as being completely different from all previous cycles post the Dalton Minimum. This is my observation not speculation but this is my opinion and as times goes by this will become much clearer.
Thus far I see very little correlation between sunspot number/solar flux versus ap index/solar wind.
One reason I believe for this are coronal holes which have impacted the speed of the solar wind /ap index of late why sunspot activity has been pretty much the same.
This is just my observation and I am not going to draw any definite conclusions until this plays out more.
This cycle is just different to me.
http://www.solen.info/solar/images/comparison_similar_cycles.png
This cycle looks very different from me. Look at the comparisons..
As the solar wind speed increases in the last half of a solar cycle, we will expect a significant increase of geomagnetic activity in the coming years. There is significant correlations, they are, however not simple, but nevertheless well-understood.
The solar variation of the relevant quantities is shown here:
http://www.leif.org/research/Solar-Wind-Climatology.png
We can calculate geomagnetic activity, A, accurately from the formula
A ~ B V^2 n^(1/3) where A could be any of the aa or ap class of indices, B is the heliospheric magnetic field, V the solar wind speed, and n the solar wind density, all measured near the Earth.
All this is well-understood physics
http://www.solen.info/solar/images/comparison_recent_cycles.png
Even more of a difference in contrast to more recent solar cycles.
As the solar wind speed increases in the last half of a solar cycle, we will expect a significant increase of geomagnetic activity in the coming years.
My reply
Yes this is what I am starting to notice already. It will be interesting to see if this trend continues as it has done in the past.
I see no reason why it shouldn’t as SC24 is quite normal in many respects.
In your paper, Calibration of Sunspot Numbers, you conclude that the sunspot number as currently defined may no longer be a suitable proxy. “Should such deviations from `normal’ observed sunspot activity be substantiated in the near future, the question naturally arises whether [and when] they might have occurred in the past as well, e.g. during the Maunder Minimum, 1645-1715.”
In that paper, you reference the following slide presentation by Ken Tapping, Properties of the Sunspot Number and 10.7cm Solar Radio Flux Indices, Their Inter-Relationship and Unusual Behaviour Since the Year 2000,
with lecture description here. The concluding slide of the presentation summarizes the descrepancies.
Naturally, I remain suspicious of your mercury thermometer analogy when describing the ‘physics’ of the sunspot number.
You are barking up the wrong tree. We do not know the physics of the sunspot number. We know the physics of the F10.7, the EUV, and the interaction with the sun’s magnetic field. The sunspot number as currently defined is deficient in fitting those other, well-understood, variables. Our work points that out and we suggest correcting the wrong sunspot number to match the well-understood indices. So, the fault is with the sunspot number, not with the ‘proxies’. The latter being simply analogous to the proxy consisting of the length of a string of mercury in a thermometer.
Found the ppt file which appears to be the Supplementary Data Section of your paper, providing a detailed reconstruction for the years 1834 to 2014 using the proxy based upon the F 10.7 cm radio signal.
Use of the Mg II core-to-wing ratio rather than the F 10.7 cm proxy reduces the RMS error by 13% to 40%, according to the paper The Mg II Index: A Proxy for Solar EUV by Viereck et al. The Mg II index reduces the 81 day delay for the F 10.7 proxy down to 13 days.
Another paper, Modified solar flux index for upper atmospheric applications by Takashi Maruyama produces an “MEI 10.7” proxy calculated using a neural network, further reducing the RMS error. The author notes by applying the same neural learning techniques to the Mg II proxy rather than the F 10.7 cm proxy, the RMS error could be reduced even more.
Cheers!
Since you have become interested in the MG II index, you might enjoy my correction of the spacecraft data: http://www.leif.org/research/MgII%20Calibration.pdf
The best proxy is the geomagnetic response as that is the only one going back far enough to be important. Because we know the physics we can simply use the Earth itself as our measuring device.
The problem with correlating EUV and F10.7 is that while F10.7 has no instrumental degradation, EUV has making it sort of meaningless to compare directly, see Fig. 2 of http://www.leif.org/research/Reconstruction-of-Solar-EUV-Flux-1834-2014.pdf
When the degradation is corrected for, F10.7 and EUV match each other very closely.
Yes, Space Environment Technologies Solar Irradiance Platform (http://spacewx.com) provided Maruyama with EUV signal data for his paper (2011).
Viereck et al. (2000) notes, “Models of solar EUV irradiance (e.g. [Hintergger, 1976] use F10.7 and the commonly used Mass Spectrometer/Incoherent Scatter Radar (MSIS) [Hedin et al., 1977] uses F10.7 as the solar forcing function. The values used for input into these models are the daily and the 81-day running mean of the F10.7. We will use the combined F10.7+F10.7avg in our comparisons of solar irradiance and irradiance proxies.”
So, instead of using MSIS, the authors chose the 3 solar day average of the F10.7 signal in their model, in addition to the daily signal, to produce the F10.7 index, or 0.5 (F10.7 + F10.7avg81).
The correlation between the F10.7 signal and the EUV SEM signal was 0.959, while the correlation coefficient between the F10.7 index versus EUV was 0.983. In the period of low solar activity around 1996, use of the F10.7 index consistently overestimated the EUV signal, according to the authors.
In the period of low solar activity around 1996, use of the F10.7 index consistently overestimated the EUV signal, according to the authors.
Mostly because the EUV signal was a bit too weak because of degradation of the instrument.
OK. Please educate me about the continuing downtrend of reported solar cycle minimum TSI values over time.
http://spot.colorado.edu/~koppg/TSI/TSI.jpg
You’ve said before that the differences are due to better instruments, and today’s TSI of 1361 (at solar minimum of each cycle) is “accurate”. Fine.
But look at the reported minimum at each solar cycle over time:
So, if “today’s” actual TSI solar radiation is 1362 watts/m^2 at the average earth orbit, then today’s calculations using “any” TSI value at all = 1361 should be accurate, right. (Basically, I’, redundant: If water boils at 100 deg C today, then all over the world, water boils at 100 deg C.) But if yesterday’s thermometers were WRONG (and they read water boiling at 101 deg C, then do not ALL previous calculations involving ANY temperature calculation or radiation heat balance have to re-done using the actual “today’s instruments” lower TSI of 1361.
The “total” credit of doubling CO2 is only 3 watts/m^2. Here, it appears we are looking at a difference in input radiation of almost 11.5 watts / m^2 at top of atmosphere since 1986. Now, water is NOT boiling at a different temperature (that we know of at any rate) between 1986 and 2015; and you state that the sun is NOT changing its thermal output between 1986 and today’s solar cycle 24 maximum. But, do not every calculation and every computer program run between 1986 and 2014 using ANY value of TSI other than 1361 watts/m^2 require “repair” and “recalibration” to the right TOA values?
This paper http://www.leif.org/EOS/2010GL045777 explains the adjustments of TSI
Not when the SOHO satellite was launched on December 2, 1995.
Solar EUV flux(0. 1-50 nm), F 10. 7 cm flux, sunspot number and the total electron content in the crest region of equatorial ionization anomaly during the deep minimum reported even more difficulty resolving the F10.7 signal with EUV data in the 2008-2009 period.
The Mg II index used by Viereck et al. was 13 days, or half of a solar day, obtaining correlation coefficient of 0.996 for the four year 5 month sample.
Longer term calculation of the Mg II index is not as straight forward. See A composite Mg II index spanning from 1978 to 2003.
(Now that I try to open the link, http://nopr.niscair.res.in is not found, however, this is the google search: https://scholar.google.com/scholar?q=Solar+EUV+flux%280.+1-50+nm%29%2C+F+10.+7+cm+flux%2C+sunspot+number+and+the+total+electron+content+in+the+crest+region+of+equatorial+ionization+anomaly+during+the+deep+minimum)
You are not paying attention. Figure 2 of http://www.leif.org/research/Reconstruction-of-Solar-EUV-Flux-1834-2014.pdf shows that the SOHO EUV signal degrades with time. After correction for the degradation the flux matches very accurately the EUV flux from the Solar EUV Experiment (SEE) data from the NASA ‘Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics (TIMED)’ mission. Read lines 195-202 of my paper.
Thus F10.7 and the EUV flux and MG II [as I showed earlier] all match each other and there are no discrepancies. You have to come off the idea that there are problems with these things [after they have been suitably calibrated and corrected]. They are all extremely good proxies for true solar activity. That they don’t match the sunspot number too well is due to deficiencies in the SSN. and we are in the process to correcting those know errors.
No. All papers account for the degradation, except for the one by Viereck et al. (2000) In that case, the degradation was so small, that had the degradation been discovered, it would not have affected the result.
If that small degradation didn’t matter, why did you make a big deal about it?
And why do you say ‘no’? What exactly is it that you are objecting too?
As you will recall, it was your paper that described the Mg II index as being averaged over a full solar cycle.
The paper by Viereck et al. (2000) used a half cycle.
That paper, together with the one by Chakrabarty et al.(2011), show that all F10.7 derived proxies overstated the EUV signal for the entire duration of the last two solar minimums.
Again, the paper Viereck et al. (2000) did not use the degradation of the SOHO SEM because the degradation had not yet been discovered, and by early 2000, the degradation was too small to affect their results.
The papers by Maruyama (2011) and Chakrabarty et al.(2011) do account for the SOHO SEM degradation.
(The http://nopr.niscair.res.in server is still down, but I downloaded Chakrabarty et al.(2011) earlier.)
You are particularly dense today. The problems is that the SOHO [SEM] EUV measurements suffer from uncorrected residual degradation [over and above that already corrected for]. You can see this clearly by comparing with the SEE EUV flux measured by TIMED as I refer to in Figure 2 and by comparing with F10.7. There are no differences in trends between Mg II, F10.7, Total Electron Content [TEC], and EUV flux. Because of contamination of SOHO/SEM data the whole data set must be re-calculated, but this has not yet been done.
http://www.leif.org/EOS/2010GL045777.pdf
Thank you. (ref: http://www.leif.org/EOS/2010GL045777.pdf)
1. This reference, provided with neither your acceptance nor your approval/imprimatur/endorsement (nor your disagreement), does then confirm what my observation above concluded: All Anthropogenic Global Warming calculations and programs run prior to 2010 using ANY value of TSI NOT equal to 1361.5 watts/m^2 MUST be redone, and ANY Anthropogenic Global Warming calculation or computer run performed AFTER publication of that paper in 2010 MUST use 1361.5 watts/m^2 or be considered – to be blunt – dead wrong.
2. I note their description for Figure 2 with interest:
Is this also just an example of “curve fitting” of TOA solar radiation changes over time, assumed earth-bound trends observed 1980-2010, and one global average temperature plot … added and subtracted together to create yet another “anthropogenic global warming signal” plot?
The adjustments of TSI are done without reference to any climate models or assumptions, so no curve fitting to climate. That the influence of TSI on the climate is minute is well-documented, see e.g. http://www.leif.org/EOS/2011GL046658.pdf :
“The marginally significant decrease in TSI during the least active phases of the Maunder Minimum by 140 to 360 ppm relative to 1996 suggests that drivers other than TSI dominate Earth’s long‐term climate change.”
[140 to 360 ppm ? Why ppm for TSI units? .mod]
TSI researchers usually work in parts per million [ppm] as the various sources of errors are of the order of 1-200 ppm, and it is easier to work with 10 ppm than with 0.000014 W/m2
So I should think of the “unit” as a part-per-millionth of a TSI?
Thank you.
Well, if it says ‘ppm’ it is part-per-million [of TSI or whatever the ppms are of].
Perhaps its the authors attempt at a shorthanded way of stating their hypothesis.
Using ppm is standard procedure in this business.
Haste is waste: 10 ppm is 0.0014 W/m2.
Gee, it is getting late here. 10 ppm is 0.014 w/m2.
IMHO opinion, the change in TSI is so small that it doesn’t matter much for the climate models.
The solar minimum of 1996 did not require an adjustment since the SOHO was placed into orbit the previous December.
This is what a corrected graph of EUV data looks like taken from this article. “Current (Version 3.1) calibrated irradiance measurements from the on-orbit SEM are in agreement with all sounding rocket measurements (which includes a total of eight sounding rocket flights between 1996 and 2012) to within about 5%”, the authors state.
Just to be sure, I’m checking with Dr. Chakrabarty to see if they accounted for the discrepancy in their paper for the 2008-2009 solar minimum.
I explained to Dr. Chakrabarty that I have a colleague that insists on applying the discrepancy twice, in the opposite direction!
Space Environment Technologies has a free 30 day trial of their Solar Irradiance Platform at http://spacewx.com , if necessary.
The Figure shows a reconstruction [SOLMOD] of EUV in the narrow wavelength range 26-34 nm compared to the uncorrecteed for residual degradation SEM data, so, no cigar.
The Haberreiter paper states:
“Recent refinements to the SEM data processing algorithm (Wieman et al. 2014) for the period of overlap between the SOHO and SDO missions have resulted in calibrated SEM irradiance values which are in better agreement with those from SDO/EVE (Woods et al. 2012). The most pronounced effect of these refinements is a systematic reduction of approximately 20% in the values of the SEM 26–34 nm irradiance compared to the SEM Version 3.1 values. While a new release of the SEM data based on this revised data processing approach is imminent, we compare the SOLMOD reconstruction with the Version 3.1 SEM irradiances as they are, at the time of the present work…”
So they recognize that version 3.1 still needs a further correction which is what I have done in Figure 2 of http://www.leif.org/research/Reconstruction-of-Solar-EUV-Flux-1834-2014.pdf in order to have SEM match the SEE flux from TIMED [and F10.7]. Bottom line: All our EUV measurements and reconstructions agree when appropriate correction for degradation is made. I have lost track of what it is you want to show.
Thank you for your patients in loking at my question. (er, patience.) You did answer the primary issue:
1. The actual TSI has been reset (or established more accurately – depending on how you want to phrase it) to a lower numerical value.
2. The sun’s actual radiation levels at the earth’s average orbit distance has NOT changed (other than the known cyclical, daily and sunspot count variations) already accounted for.
3. ANY solar radiation “balance” calculation or computer simulation using ANY TSI input made prior to this paper issue in 2010 must be de-done with the correct lower irradiation level of 1361.3 watts/m^2.
4. ALL future solar radiation balances made after 2010 MUST use the corrected TSI radiation levels or they will predict the wrong (too high) global warming influence for the future. That is, because ANY radiation balance made prior to 2010 assumes too high an “energy in” value, the
required “energy out” value will be too high, and thus man’s contribution to the energy balance will always be too high. (Assuming the intermediate calculations and coefficients are correct of course.)
Revised downward, not upward as you have done!
The disparity between the F10.7 signal and the EUV bands would become even more pronounced if values around the solar minimums decrease by 20%!
You are not paying attention. We have two spacecraft measurement series, SOHO-SEM and TIMED-SEE. The SEE data has been corrected for degradation, while the SEM data [version 3.1] still has some un-accounted for degradation. My correction [deduced from F10.7] brings SEM in almost perfect agreement with SEE, and makes all our proxies and series agree: SEM, SEE, TEC, F10.7, MG II, geomagnetic data. What is not to like?
And a tiny voice pipes up from the back of the classroom — THIS IS GREAT! Thank you, esp. Dr. Svalgaard and R. A. Cook (I only read the bottom dozen or so posts of this thread today) for the GREAT EDUCATION!
@ur momisugly Jones guy — your writing, IMHO, really could use some more detail for clarity… I know you know what you think you wrote but you seem not to know that what you wrote does not make us think what you thought.
Point well taken. I have been told as much in the past.
In my defense, the threads became crossed, and, for the time being at least, Dr. Svalgaard chooses not to comprehend my point!
It is hard to make sense of ‘your point’ as it ignores the direct spacecraft measurements [SEM compared with SEE]. In addition, it is not clear [in view of that] what your point is. My point is that all the proxies and all the spacecraft data agree when corrected for detected [and so far unaccounted for] degradation.
Generally, the proxies do agree and are highly correlated, however, the behavior of the often used F10.7cm signal during the solar minimums is disturbing.
For the minimum of 1996, the paper The Mg II Index: A Proxy for Solar EUV by Viereck et al., notes that use of the F10.7 signal or index consistanly underestimated the EUV 26-34nm signal throught the minimum. While overall correlations were high between the F10.7 data and the EUV data, they simply overshoot the EUV 26-34nm signal for the entire minimum.
For the minimum of 2008-2009, the paper Solar EUV flux(0. 1-50 nm), F 10. 7 cm flux, sunspot number and the total electron content in the crest region of equatorial ionization anomaly during the deep minimum by Chakrabarty et al. notes that the discrepancy between the F10.7 signal and the EUV 0.1-50nm signal doubled from the 1996 minimum.
How are we to reliably reconstruct the EUV signals during minimums in the past, thus preserving our climate record?
The question I have resisted asking thus far is, “Would the rY signal discussed in the paper Reconstruction of Solar EUV Flux 1834 2014 provide a more robust EUV proxy than does the F10.7 signal?”
(The difference is not due to the discrepancies between the raw and corrected EUV data sets.)
Measuring EUV directly is very difficult because of severe degradation, so the proxies are actually much more reliable indicators of EUV than our shaky direct measurements. In particular the rY signal uses the Earth itself as the measuring device and allows us to go back to 1834 with confidence and to ~1740 with less accuracy. Bottom line: if there are any discrepancy between EUV and the proxies, the fault is with EUV [SOHO/SEM; TIMED/SEE has correct corection for degradation].
“Bottom line: if there are any discrepancy between EUV and the proxies, the fault is with EUV [SOHO/SEM; TIMED/SEE has correct corection for degradation].”
Among other practical uses, The SOHO SEM EUV signals are used to calculate drag as satellites and spacecraft travel through the ionosphere. The goal is to provide more accuracy, which explains the data versions, and explains why anomalous EUV irradiance is so distressing.
The true EUV irradiance is not anomalous. The SOHO/SEM is just wrong and will be corrected soon when version 3.1 is finally dumped. And the small error is SEM is much less than the errors in the [40-year old?] model used to calculate drag, anyway.
I checked further through the references section of Chakrabarty et al(2011) and found the paper Anomalously low solar extreme-ultraviolet irradiance and thermospheric density during solar minimum by Solomon et al. to be more revealing concerning the EUV data sources.
They are exhaustive, and include the SOHO SEM “calibrated with similar instruments on eight suborbital rocket flights, and have a 6% estimated uncertainty.”
Still doesn’t matter. The real uncertainty is probably more like 20% as needed to agree with SDO/EVE.
Why don’t you look at the TIMED/SEE data? The SOHO/SEM data is being re-calibrated as we speak and version 3.1 that everybody uses is simply no good. Some people’s reluctance to let go of old, obsolete, and wrong data is quite amazing. Perhaps they desperately need confirmation bias. Which is yours?
The Solar EUV Experiment (SEE) on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics (TIMED) satellite was also included in the analysis by Solomon at al.(2010) above.
And?
If you plot SEE you will find that it matches F10.7 precisely.
Solomon et al(2011) concluded that an Anomalously low solar extreme-ultraviolet irradiance and thermospheric density during solar minimum had occurred which the F10.7 signal did not detect!
And which the TIMED/SEE EUV measurements did not detect. The Solomon paper is old [in this rapidly developing field]. The thermospheric density computed from F10.7 is done with a 40+ year old model which is not precise enough.
If you say so.
Seems a bit early to write off a Maunder Minimum, though, as you have pointed out, there is not sufficient proof.
I wait with interest for further information as it becomes available.
And thanks for all your help, Dr. Svalgaard.
You are welcome. BTW, I do think that a Mauder Minimum soon is a possibility, we just don’t really know. cycle 25 will probably [judging from the polar fields] be like cycle 24, so a new MM is some ways out.
Thank you, Jones guy, for that gracious response.
Slide 26 of http://www.leif.org/research/Reconstruction-Solar-EUV-Flux.pdf shows how well-behaved F10.7 is and how exquisitely it follows rY. Nothing wrong with, or ‘disturbing’, the F10.7 microwave flux.