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Post by elbuho on Dec 20, 2010 2:06:36 GMT
When started the 14 cycle? April 1901 or February 1902?
Thank you
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Post by lsvalgaard on Dec 20, 2010 4:11:17 GMT
When started the 14 cycle? April 1901 or February 1902? Thank you 190103 1901.205 4.5 3.9 190104 1901.287 0.0 3.2 190105 1901.372 10.2 2.8 190106 1901.454 5.8 2.8 190107 1901.539 0.7 3.0 190108 1901.624 1.0 3.1 190109 1901.706 0.6 3.3 190110 1901.791 3.7 3.6 190111 1901.873 3.8 3.3 190112 1901.958 0.0 2.8 190201 1902.042 5.5 2.7 190202 1902.122 0.0 2.7 190203 1902.204 12.4 3.1 190204 1902.286 0.0 3.9 Either May 1901 or Jan. 1902, but hard to pin down. There is no 'official' time. Personally, I would put the time halfway between the two choices, e.g. Oct. 1901, but the exact time of minimum is somewhat unphysical and just a statistical accident. |
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Post by prewratrap on Dec 21, 2010 5:35:26 GMT
Dr. Svalgaard,
It looks to me like most of the graphs are showing low end ouput by our sun. Especially from the solar flux curve it looks like the trend is going to be lower than predicted. Will a lower cycle peak extend or shorten the duration of the present solar cycle 24?
Do you think this cycle is exhibtting more similarity to solar cycle 5?
What do you take of recent sunspot free days?
Thanks
Mark
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Post by lsvalgaard on Dec 21, 2010 7:18:30 GMT
Dr. Svalgaard, It looks to me like most of the graphs are showing low end ouput by our sun. Especially from the solar flux curve it looks like the trend is going to be lower than predicted. Will a lower cycle peak extend or shorten the duration of the present solar cycle 24? Do you think this cycle is exhibtting more similarity to solar cycle 5? What do you take of recent sunspot free days? Thanks Mark low cycle is longer [usually] SC24 is more like SC14 than SC5 [so far] Spot free days can happen well into a low cycle [as we have now]. |
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Post by duwayne on Dec 21, 2010 11:04:08 GMT
Dr. Svalgaard,
Your longstanding forecast of low solar activity for Cycle 24 is right on the mark so far. Do you believe Cycle 24 is the beginning of a period of low activity perhaps like SC 10-15 or more of a random event?
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Post by lsvalgaard on Dec 21, 2010 19:55:22 GMT
Dr. Svalgaard, Your longstanding forecast of low solar activity for Cycle 24 is right on the mark so far. Do you believe Cycle 24 is the beginning of a period of low activity perhaps like SC 10-15 or more of a random event? I think there will be several low cycles, but this is guesswork. The argument for the next cycle to be low is that if there are only few active regions it is harder to build up a new polar fields from the diminished magnetic flux. Eventually this pattern will be broken and we'll get a large region to the pole. The polar fields only have the flux of a handful of regions, so large random variations are possible, like throwing four heads in a row. |
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Post by elbuho on Dec 22, 2010 0:58:07 GMT
Comparing cycle 14 to 24 in the initial phase. SSN=0 Cycle 14 1901/10/01 - 1901/12/31 = 68 1902 = 237 1903 = 45 Total in the 820 first days of 14 cycle, 358 ssn=0 Cycle 24 2008/09/22 - 2008/12/31 = 72 2009 = 262 2010/01/01 - 2010/12/22 = 42 Total in the beggining cycle 24, 376 ssn=0  Is this cycle weaker than the 14 cycle? |
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Post by lsvalgaard on Dec 22, 2010 5:51:17 GMT
Comparing cycle 14 to 24 in the initial phase. SSN=0 Cycle 14 1901/10/01 - 1901/12/31 = 68 1902 = 237 1903 = 45 Total in the 820 first days of 14 cycle, 358 ssn=0 Cycle 24 2008/09/22 - 2008/12/31 = 72 2009 = 262 2010/01/01 - 2010/12/22 = 42 Total in the beggining cycle 24, 376 ssn=0 Is this cycle weaker than the 14 cycle? too early to tell. |
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Post by hunterson on Dec 22, 2010 13:01:40 GMT
Season's Greetings to everyone here.
And best wishes for a prosperous and healthy New Year.
My question for the good Dr. is this:
Is there any evidence of a conservation process in the sun's activity, where it evens out over time? For instance, would a huge CME event possibly offset the current period of relative quiet?
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Post by lsvalgaard on Dec 22, 2010 21:29:07 GMT
I think there will be several low cycles, but this is guesswork. The argument for the next cycle to be low is that if there are only few active regions it is harder to build up a new polar fields from the diminished magnetic flux. Eventually this pattern will be broken and we'll get a large region to the pole. The polar fields only have the flux of a handful of regions, so large random variations are possible, like throwing four heads in a row. That is not particularly a surprising news. In 2003 I wrote formula predicting just that. Your formula is just curve fitting and has no predictive power. We have known for 150 years that there is an about 100 yr quasi-cycle so it is not hard to guess that we are due for some low cycles. For SC24 this is not guesswork, however, as we know the polar fields are low. |
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Post by elbuho on Dec 26, 2010 22:58:07 GMT
Comparing cycle 14 to 24 in the initial phase. SSN=0 Cycle 14 1901/10/01 - 1901/12/31 = 68 1902 = 237 1903 = 45 Total in the 820 first days of 14 cycle, 358 ssn=0 Cycle 24 2008/09/22 - 2008/12/31 = 72 2009 = 262 2010/01/01 - 2010/12/22 = 42 Total in the beggining cycle 24, 376 ssn=0 Is this cycle weaker than the 14 cycle? too early to tell. Dear Doctor, 7 consecutive days to 0 at this stage of cycle 24. Is this quite normal? Unusual? Frequently? Thanks for your patience. Merry Christmas and Happy New Year. |
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Post by lsvalgaard on Dec 27, 2010 6:35:02 GMT
Dear Doctor, 7 consecutive days to 0 at this stage of cycle 24. Is this quite normal? Unusual? Frequently? Thanks for your patience. Merry Christmas and Happy New Year. As I think SC24 might be like SC14, we can go and look at that one. In September 1903, well into that cycle the sunspot numbers were: 1903 9 1 1903.666 0 1903 9 2 1903.669 0 1903 9 3 1903.672 0 1903 9 4 1903.674 0 1903 9 5 1903.677 8 1903 9 6 1903.680 0 1903 9 7 1903.682 0 1903 9 8 1903.685 0 1903 920 1903.718 0 1903 921 1903.721 0 1903 922 1903.724 0 so this happens. Also in the next cycle: 1915 511 1915.357 0 1915 512 1915.359 0 1915 513 1915.362 0 1915 514 1915.365 0 1915 515 1915.368 0 1915 516 1915.370 0 1915 517 1915.373 0 1915 518 1915.376 0 1915 519 1915.379 0 |
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Post by toughluck on Dec 27, 2010 15:29:01 GMT
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Post by lsvalgaard on Dec 27, 2010 18:24:19 GMT
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Post by af4ex on Dec 28, 2010 17:23:44 GMT
Dr. Svalgaard, I've noticed that SOHO/SDO EUV imagery at the 171A wavelength is remarkable for its ability to render the magnetic field lines around the active regions. I thought maybe it had something to do with gyro-frequency emissions from accelerating charged particles spiraling along the field lines. But that's usually a much lower frequency, in the RF range I think. So, it seems to me this must be an atomic excitation property of the solar gases. Why does it seem to happen most clearly at 171A? What's going on? In the image one can clearly see the magnetic lines around 1137 and 1138. And I think (trying not to jump to an unwarranted conclusion) that I can see a few magnetic lines spewing out of the "old 1121" region, which is just emerging on the SE limb. Is there any way to estimate the magnetic field strength from the curvature of the lines? [SOHO EIT 171] Attachments:
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