|
Post by fabron on Sept 19, 2010 19:44:02 GMT
|
|
|
Post by lsvalgaard on Sept 19, 2010 20:31:43 GMT
Different records [especially 14C] show slightly different variations. The high-quality NGRIP 10Be record [Berggren et al., www.leif.org/EOS/2009GL038004.pdf ] see Figure 2 panels a and d, shows that the modulation was comparable to the modern one...
|
|
|
Post by Pooh on Sept 27, 2010 15:24:26 GMT
Food for thought: a recent paper by Livingston and Penn. (The cautious paragraphs at the end of their paper is a welcome mark of scientists at work.) Penn, Matthew, and William Livingston. “Long-term Evolution of Sunspot Magnetic Fields.” 1009.0784 (September 3, 2010). arxiv.org/abs/1009.0784From the paper: arxiv.org/PS_cache/arxiv/pdf/1009/1009.0784v1.pdf"Independent of the normal solar cycle, a decrease in the sunspot magnetic field strength has been observed using the Zeeman-split 1564.8nm Fe I spectral line at the NSO Kitt Peak McMath-Pierce telescope. Corresponding changes in sunspot brightness and the strength of molecular absorption lines were also seen. This trend was seen to continue in observations of the first sunspots of the new solar Cycle 24, and extrapolating a linear fit to this trend would lead to only half the number of spots in Cycle 24 compared to Cycle 23, and imply virtually no sunspots in Cycle 25. We examined synoptic observations from the NSO Kitt Peak Vacuum Telescope and initially (with 4000 spots) found a change in sunspot brightness which roughly agreed with the infrared observations. A more detailed examination (with 13,000 spots) of both spot brightness and line-of-sight magnetic flux reveals that the relationship of the sunspot magnetic fields with spot brightness and size remain constant during the solar cycle. There are only small temporal variations in the spot brightness, size, and line-of-sight flux seen in this larger sample. Because of the apparent disagreement between the two data sets, we discuss how the infrared spectral line provides a uniquely direct measurement of the magnetic fields in sunspots." Page 7: (Caveats. Note that "PDF" abbreviates "probability distribution function") "It is important to note that it is always risky to extrapolate linear trends; but the importance of the implications from making such an assumption justify its mention. Also of note is that while these PDFs are drawn from Livingston’s observations, they are at best proxies for the true sunspot magnetic PDFs. While a sunspot with a magnetic field strength of 4200 Gauss was observed in Cycle 23 (NOAA 10930, Moon et al. (2007)), it was not observed by Livingston and does not appear in this analysis. Thus the sunspot which appeared recently in Cycle 24 (NOAA 11092, August 2010) with a magnetic field strength of 3350 Gauss does not invalidate these assumptions. Certainly if a large number of sunspots with magnetic field strengths greater than 3000 Gauss do appear, then the extrapolated PDF will be shown to be erroneous. We will see in the coming months and years.
"Umbral magnetic field measurements at 1564.8nm have been shown to reveal differences between the decay phase of Cycle 23 and the rise phase of Cycle 24, and they imply that the next two sunspot cycles might be very different from the last one. Observations with visible light magnetographs do not show significant support for these claims. Thus we feel it is essential to make synoptic observations using this very favorable infrared line to determine if these trends continue. It is essential to save the spectra and calibrations, and it would be very useful to make synoptic measurements of sunspots using temperature sensitive molecular lines such as the lines of OH near 1564.8nm."
|
|
|
Post by csspider57 on Sept 27, 2010 22:19:27 GMT
re: 10Be record Greenland 10Be data for period 1700-1830 are corrupted. Data from the Antarctica should be far more reliable. Volcanic corruption or something else. Good to see you reinstated? With full seniority rights? Watch out for Roy Rogers and Dale Evans though ok..ok..
|
|
|
Post by lsvalgaard on Sept 28, 2010 5:02:35 GMT
re: 10Be record Greenland 10Be data for period 1700-1830 are corrupted. Data from the Antarctica should be far more reliable. No, the record is fine: www.leif.org/EOS/2009GL038004.pdf
|
|
|
Post by fredfriendly on Sept 28, 2010 10:13:37 GMT
Anyone who simply states the record is fine kinda makes me suspect. Leif, what are the biggest issues with the record? Did the Indonesia event in 1815 corrupt any record? It cused the coldest year ever in the northern hem, I cant quite buy it did nothing else? Why arent other eruptions corrupting the record? Which eruptions did at least effect it?
|
|
|
Post by lsvalgaard on Sept 28, 2010 11:48:31 GMT
Anyone who simply states the record is fine kinda makes me suspect. Leif, what are the biggest issues with the record? Did the Indonesia event in 1815 corrupt any record? It cused the coldest year ever in the northern hem, I cant quite buy it did nothing else? Why arent other eruptions corrupting the record? Which eruptions did at least effect it? I would think that the ones claiming the record is corrupted have to explain that. But, of course, the 10Be record is just that and therefore cannot be said to be corrupted unless one demonstrates that there are measurement or reporting errors. That said, the real issue is the interpretation of the record, and here various people have a a 'corrupted' view, some tainted by agendas, some by ignorance, some by wishful thinking, etc. At all times, the 10Be record [at any given location] is the result of several factors: 1) Cosmic ray intensity [from Galaxy, modulated by solar activity] 2) Geomagnetic field [and its variation] 3) Climate and weather 4) Volcanic eruptions All of those are large effects and it is not clear how to separate them cleanly [at this point in time - we may learn how to eventually].
|
|
|
Post by france on Oct 8, 2010 9:02:02 GMT
Dr Svalgaard I know a retired geophysicist he says the reason comes from the exchanges ground-atmosphere. What I resumed with the more modern scientific notion of "compensation" (equalization). Did you have a look to this graph ?
|
|
|
Post by lsvalgaard on Oct 8, 2010 11:07:58 GMT
Did you have a look to this graph ? Yes, it is the 'predicted' distribution of magnetic field values should L&P turn out to be correct.
|
|
|
Post by karlox on Oct 8, 2010 15:23:05 GMT
Dr Svalgaard, I´ve just realized that when you make it clear that: quote At all times, the 10Be record [at any given location] is the result of several factors: 1) Cosmic ray intensity [from Galaxy, modulated by solar activity] 2) Geomagnetic field [and its variation] 3) Climate and weather 4) Volcanic eruptions All of those are large effects and it is not clear how to separate them cleanly [at this point in time - we may learn how to eventually]. unquote ...related to 10Be record... "modulated by solar activity" point 1 (cosmic ray intensity)... well, that same applies for points 2, 3 and 4 -"modulated by solar activity", I mean- that according to more or less founded theories- I´ve had the pleasure to first hear and learn about through these threads in the past years- "suspect" in all cases: Cosmic Ray, Climate/Weather/ Geomagnetic field/Vulcanism is at last "Sun". Talking about 10Be record only? Beg your pardon, just wandering arouund... thanks for your time Carlos Madrid (Spain)
|
|
|
Post by lsvalgaard on Oct 8, 2010 16:57:30 GMT
Dr Svalgaard, I´ve just realized that when you make it clear that: quote At all times, the 10Be record [at any given location] is the result of several factors: 1) Cosmic ray intensity [from Galaxy, modulated by solar activity] 2) Geomagnetic field [and its variation] 3) Climate and weather 4) Volcanic eruptions All of those are large effects and it is not clear how to separate them cleanly [at this point in time - we may learn how to eventually]. unquote ...related to 10Be record... "modulated by solar activity" point 1 (cosmic ray intensity)... well, that same applies for points 2, 3 and 4 -"modulated by solar activity", I mean- that according to more or less founded theories- I´ve had the pleasure to first hear and learn about through these threads in the past years- "suspect" in all cases: Cosmic Ray, Climate/Weather/ Geomagnetic field/Vulcanism is at last "Sun". Talking about 10Be record only? Beg your pardon, just wandering arouund... thanks for your time Carlos Madrid (Spain) No, there is very little [or no] evidence that the other points are modulated by by solar activity. Lots of claims they are, but claims do not establish reality. For point 3, there MAY be a weak dependence, but not enough to influence the 10Be production.
|
|
|
Post by karlox on Oct 8, 2010 17:49:40 GMT
Dr Svalgaard, I´ve just realized that when you make it clear that: quote At all times, the 10Be record [at any given location] is the result of several factors: 1) Cosmic ray intensity [from Galaxy, modulated by solar activity] 2) Geomagnetic field [and its variation] 3) Climate and weather 4) Volcanic eruptions All of those are large effects and it is not clear how to separate them cleanly [at this point in time - we may learn how to eventually]. unquote ...related to 10Be record... "modulated by solar activity" point 1 (cosmic ray intensity)... well, that same applies for points 2, 3 and 4 -"modulated by solar activity", I mean- that according to more or less founded theories- I´ve had the pleasure to first hear and learn about through these threads in the past years- "suspect" in all cases: Cosmic Ray, Climate/Weather/ Geomagnetic field/Vulcanism is at last "Sun". Talking about 10Be record only? Beg your pardon, just wandering arouund... thanks for your time Carlos Madrid (Spain) No, there is very little [or no] evidence that the other points are modulated by by solar activity. Lots of claims they are, but claims do not establish reality. For point 3, there MAY be a weak dependence, but not enough to influence the 10Be production. Thanks! One more, please, not neccesarly related with !0Be decay rate or production etc, isn´t it earth´s geomagnetic field strenght and variability closely relaty to sun´s ones? Thanks again
|
|
|
Post by lsvalgaard on Oct 8, 2010 20:49:04 GMT
No, there is very little [or no] evidence that the other points are modulated by by solar activity. Lots of claims they are, but claims do not establish reality. For point 3, there MAY be a weak dependence, but not enough to influence the 10Be production. Thanks! One more, please, not neccesarly related with 10Be decay rate or production etc, isn´t it earth´s geomagnetic field strenght and variability closely relaty to sun´s ones? Thanks again No, not really. The Earth's main magnetic is generated deep within the core of the Earth. Solar activity adds just a tiny fraction of that on top.
|
|
|
Post by Bob k6tr on Oct 9, 2010 0:24:25 GMT
Did you have a look to this graph ? Yes, it is the 'predicted' distribution of magnetic field values should L&P turn out to be correct. The labelling of the Y Axis is somewhat vague. I devise that it is Sunspot "Number" Assuming that the graph itself is puslling. Why would Sunspot count go down as umbral magnetic intensity increases ? Why would a magnetic intensity of 1500 Gauss yield a spot count of 90 for Cycle 24 yet render less than 10 for Cycle 25 and 0 for Cycle 23 ?
|
|
|
Post by lsvalgaard on Oct 9, 2010 1:40:10 GMT
Yes, it is the 'predicted' distribution of magnetic field values should L&P turn out to be correct. The labelling of the Y Axis is somewhat vague. I devise that it is Sunspot "Number" Assuming that the graph itself is puslling. Why would Sunspot count go down as umbral magnetic intensity increases ? Why would a magnetic intensity of 1500 Gauss yield a spot count of 90 for Cycle 24 yet render less than 10 for Cycle 25 and 0 for Cycle 23 ? shift SC23 to the left, then cut off at 1500 and you get SC24. Shift SC24 left, then cut off at 1500 and you get SC25...
|
|