Solar Cycle 24 Main Discussion IX

[lsvalgaard]

Dec 6, 2010 14:53:31 GMT af4ex said:

@leif
> ... Grandpa was followed three days later by a
> good size storm [Kp=8-], but no super-storm.

But what if Grandpa had been facing the Earth, can we estimate how big the storm would have been?

No.

[af4ex]

Dec 6, 2010 5:57:37 GMT Bob k6tr said:

In August 1972 earth was hit with an earth directed flare that wiped out everything in terms of HF Communications. That was quite a day. Everyone thought their radios were busted or someone had severed their coax lines. I don't remember the category of flare it was but we have never seen anything like that since. Earth took that one straight in the kisser.

The 1859 Carrington event was rated as "four times" more "proton fluence" than the August 1972 storm:
www.physicsforums.com/archive/index.php/t-322082.html
"Using high resolution measurements of the impulsive nitrate events in polar ice as identifiers of solar proton events in the past, we have identified 19 events over the period 1561–1950 that equal or exceed the >30 MeV fluence measured during the August 1972 episode of solar proton events. The largest nitrate impulsive deposition event (and largest solar proton fluence above 30 MeV) occurred in late 1859 in time association with the Carrington flare of September 1859. The Carrington flare occurred near the central meridian of the sun; the interplanetary disturbance associated with the solar activity rapidly traveled toward the earth resulting in an extremely large geomagnetic storm commencing within 17.1 h of the visual observation of the solar flare. While this event was remarkable by itself, historical records indicate that the Carrington event was part of a sequence of solar activity as an active region traversed the solar disk. We compare the derived omni-directional solar proton fluence for the Carrington event of 1.9 × 10^10 cm−2 above 30 MeV with the solar proton fluence from the past and from more recent episodes of solar activity. The Carrington event is the largest solar proton event identified in our 450 year period, having almost twice the >30 MeV solar proton fluence than the second largest event in 1895, and approximately four times the solar proton fluence of the August 1972 event."

[af4ex]

[Browsing Leif's paper on flares]
www.leif.org/research/1859%20Storm%20-%20Extreme%20Space%20Weather.pdf

There's a nice chart on pg 411 which ranks the flares since 1855 by their proton fluence. The Aug72 flare (pink) appears to be only 5th in the hierarchy, outranked by these:
Carrington 1859 (red)
1895 (green)
Nov 1960 (blue)
Nov 2003 (yellow)

The 1895 flare is cited from a 2001 paper by McCracken et al. which I don't have access to.

Leif, was the 1895 flare event reported in its time by the press or scientific literature? Can't find any historical mention of it in Google.

Attachments:

[lsvalgaard]

Dec 6, 2010 18:00:44 GMT af4ex said:

[Browsing Leif's paper on flares]
www.leif.org/research/1859%20Storm%20-%20Extreme%20Space%20Weather.pdf

There's a nice chart on pg 411 which ranks the flares since 1855 by their proton fluence. The Aug72 flare (pink) appears to be only 5th in the hierarchy, outranked by these:
Carrington 1859 (red)
1895 (green)
Nov 1960 (blue)
Nov 2003 (yellow)

The 1895 flare is cited from a 2001 paper by McCracken et al. which I don't have access to.

Leif, was the 1895 flare event reported in its time by the press or scientific literature? Can't find any historical mention of it in Google.

There did not seem to be any mention of it, so probably no southward CME. Proton events do not arrive with the solar wind anyway.

[af4ex]

@leif
> Proton events do not arrive with the solar wind anyway.

Leif, are you suggesting that a "half-Carrington" solar storm hit the Earth in 1895 and nobody noticed?

[lsvalgaard]

Dec 6, 2010 20:25:55 GMT af4ex said:

@leif
> Proton events do not arrive with the solar wind anyway.

Leif, are you suggesting that a "half-Carrington" solar storm hit the Earth in 1895 and nobody noticed?

A proton event is different from a magnetic storm. A magnetic storm would induce currents and cause aurorae. A proton event would not [except some sub-visual ones that no-one would notice]. The proton event would upset satellites and sensitive electronics and kill astronauts, but there weren't any of that stuff around...

[af4ex]

@leif
> A proton event would not [except some sub-visual
> ones that no-one would notice].

... except that it left a nitrate signature in the polar icecaps that McCracken et al. decoded.

Are there any other proxy signatures which confirm this 1895 event? Or is it all inferred from the nitrate evidence?

[af4ex]

@leif
> The proton event would upset satellites and
> sensitive electronics and kill astronauts, but there
> weren't any of that stuff around...

The Niagara Falls power station started operation in April 1895, so there were extensive power grids in operation, even then.
www.teslasociety.com/exhibition.htm

Also around that time (before vacuum tubes were invented) Nicola Tesla had invented some very sensitive silver coherer receivers, which he subsequently claimed (in 1899) to have received natural radio signals from other planets (the first radio telescope).
en.wikipedia.org/wiki/Nikola_Tesla

So I'm a little surprised that scientists like Tesla, Samuel Langley, Marconi and others in this 1895 version of the "League of Extraordinary Scientists" would have failed to notice this huge pulse of energy from the sun.

[lsvalgaard]

Dec 6, 2010 21:20:50 GMT af4ex said:

@leif
> The proton event would upset satellites and
> sensitive electronics and kill astronauts, but there
> weren't any of that stuff around...

The Niagara Falls power station started operation in April 1895, so there were extensive power grids in operation, even then.
www.teslasociety.com/exhibition.htm

Also around that time (before vacuum tubes were invented) Nicola Tesla had invented some very sensitive silver coherer receivers, which he subsequently claimed (in 1899) to have received natural radio signals from other planets (the first radio telescope).
en.wikipedia.org/wiki/Nikola_Tesla

So I'm a little surprised that scientists like Tesla, Samuel Langley, Marconi and others in this 1895 version of the "League of Extraordinary Scientists" would have failed to notice this huge pulse of energy from the sun.

The solar protons are stopped high in the atmosphere...
and the pulse is not huge. The protons are energetic but the total energy is small.

[af4ex]

@leif
> The solar protons are stopped high in the atmosphere...
> and the pulse is not huge. The protons are energetic
> but the total energy is small.

... yet it left an unmistakable sign in the polar ice?

Hmm, with all due respect Leif, without any corroborating evidence, I'm not convinced that a "solar proton event" is the only possible explanation for those nitrate signatures.

[lsvalgaard]

Dec 6, 2010 22:02:21 GMT af4ex said:

@leif
> The solar protons are stopped high in the atmosphere...
> and the pulse is not huge. The protons are energetic
> but the total energy is small.

... yet it left an unmistakable sign in the polar ice?

Hmm, with all due respect Leif, without any corroborating evidence, I'm not convinced that a "solar proton event" is the only possible explanation for those nitrate signatures.

Our instruments are VERY sensitive, and a proton event does produce NOx high in the atmosphere. The NOx is over a period of weeks slowly drawn down into the troposphere and deposited in the ice. There is no doubt about the process. This is 'textbook' stuff. Mother Nature does her stuff, you being convinced or not. ;D

[phydeaux2363]

are sunspots 1130, 1132 and 1133 near enough to the solar equator to indicate the maturation of Solar Cycle 24?

[af4ex]

Just noticed the GOES Xray background flux jumped up suddenly, and am looking at the Nobeyama microwaves for some flares.
solar.nro.nao.ac.jp/norh/html/10mins/2010/12/07/movie.html
What I'm seeing is a very unusual looking prominence on the southeastern limb (green circle) which doesn't look like it's coming from old 1123/1121 (blue circle). It's been hanging in there steadily for over an hour.

But there's no significant activity (spots or plage) in that area, even looking at the STEREO Behind image. No NOAA XRA flare reports either. No bright spots on the GOES Xray imager either (although the timestamp 1811Z is about 6 hours old).

So, what is causing the Xray background to jump now and is it possibly associated with that stuff going on right now on the SE limb?

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[Bob k6tr]

Dec 6, 2010 23:13:44 GMT phydeaux2363 said:

are sunspots 1130, 1132 and 1133 near enough to the solar equator to indicate the maturation of Solar Cycle 24?

Not even close.

At the end of a solar cycle most spots are right on the equator and vary no more than 10 to 15 degrees. 2 months ago we had a spot at 41 degrees. The position of 30, 32 and 33 would put them into the category of rogue spots if SC 24 were near an end.

Strong solarcycles peak 30 to 36 months after they begin, weak cycles peak 48 months after minimum. SC 23-24 minimum occurred in December 2008.

[phydeaux2363]

Dec 7, 2010 0:26:22 GMT Bob k6tr said:

Dec 6, 2010 23:13:44 GMT phydeaux2363 said:

are sunspots 1130, 1132 and 1133 near enough to the solar equator to indicate the maturation of Solar Cycle 24?

Not even close.

At the end of a solar cycle most spots are right on the equator and vary no more than 10 to 15 degrees. 2 months ago we had a spot at 41 degrees. The position of 30, 32 and 33 would put them into the category of rogue spots if SC 24 were near an end.

Strong solarcycles peak 30 to 36 months after they begin, weak cycles peak 48 months after minimum. SC 23-24 minimum occurred in December 2008.

Many thanks, Bob! I will keep reading and watching with interest.