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Solar Climate Linkages

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Just a couple of interesting articles that I think deserve wider readership.

Henrik Svensmark on the coming global cooling: “enjoy global warming while it lasts” (this is a Google translation from Danish, so the English is a little crazy)

While the sun sleeps

HENRIK SVENSMARK, Professor, DTU, Copenhagen

Indeed, global warming stopped and a cooling is beginning. No climate model has predicted a cooling of the Earth, on the contrary. This means that projections of future climate is unpredictable, writes Henrik Svensmark.

The star which keeps us alive, has over the last few years almost no sunspots, which are the usual signs of the sun’s magnetic activity.

Last week, reported the scientific team behind Sohosatellitten (Solar and Heliospheric Observatory) that the number of sunspot-free days suggest that solar activity is heading towards its lowest level in about 100 years’. Everything indicates that the Sun is moving into a hibernation-like state, and the obvious question is whether it has any significance for us on Earth.

If you ask the International Panel on Climate Change IPCC, representing the current consensus on climate change, so the answer is a reassuring ‘nothing’. But history and recent research suggests that it is probably completely wrong. Let us take a closer look at why.

Solar activity has always varied. Around the year 1000, we had a period of very high solar activity, which coincided with the medieval warmth. It was a period when frosts in May was an almost unknown phenomenon and of great importance for a good harvest. Vikings settled in Greenland and explored the coast of North America. For example, China’s population doubled over this period. But after about 1300, the earth began to get colder and it was the beginning of the period we now call the Little Ice Age. In this cold period all the Viking settlements in Greenland disappeared. Swedes [were surprised to see Denmark to freeze over in ice], and the Thames in London froze repeatedly. But more serious was the long periods of crop failure, which resulted in a poorly nourished population, because of disease and hunger [population was reduced] by about 30 per cent in Europe.

Read on here

New linkage between solar cycle and Earth’s atmosphere discovered

Scientists discover surprise in Earth’s upper atmosphere

By Stuart Wolpert

Heejeong Kim and Larry Lyons

Heejeong Kim and Larry Lyons

UCLA atmospheric scientists have discovered a previously unknown basic mode of energy transfer from the solar wind to the Earth’s magnetosphere. The research, federally funded by the National Science Foundation, could improve the safety and reliability of spacecraft that operate in the upper atmosphere.

“It’s like something else is heating the atmosphere besides the sun. This discovery is like finding it got hotter when the sun went down,” said Larry Lyons, UCLA professor of atmospheric and oceanic sciences and a co-author of the research, which is in press in two companion papers in the Journal of Geophysical Research.

The sun, in addition to emitting radiation, emits a stream of ionized particles called the solar wind that affects the Earth and other planets in the solar system. The solar wind, which carries the particles from the sun’s magnetic field, known as the interplanetary magnetic field, takes about three or four days to reach the Earth. When the charged electrical particles approach the Earth, they carve out a highly magnetized region — the magnetosphere — which surrounds and protects the Earth.

Charged particles carry currents, which cause significant modifications in the Earth’s magnetosphere. This region is where communications spacecraft operate and where the energy releases in space known as substorms wreak havoc on satellites, power grids and communications systems.

The rate at which the solar wind transfers energy to the magnetosphere can vary widely, but what determines the rate of energy transfer is unclear.

“We thought it was known, but we came up with a major surprise,” said Lyons, who conducted the research with Heejeong Kim, an assistant researcher in the UCLA Department of Atmospheric and Oceanic Sciences, and other colleagues.

Read on here

Written by John A

September 11, 2009 at 12:13 pm

S. Fred Singer and Terry Sloan correspond on CR deflection

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S. Fred Singer corresponds on the subject:

Some corrections to the letter from Terry Sloan:

1.  First, a minor point:  The solar particle stream (“wind”) does not ‘generate’ a mag field.  A somewhat turbulent solar surface field is ‘frozen in ‘ (a la Alfven) into the stream and decays only slowly

2.  The ‘deflection’ argument may be intuitive but doesn’t really work logically.  For every CR particle aimed at the Earth that’s deflected away, there will be one not aimed at the Earth that’s deflected to hit the Earth

3.  The 11-yr cycle seen in CR intensity (and other solar-modulated CR variations)  depend on deceleration (i e, a shift in the energy  spectrum) produced by scattering of CR from expanding regions of magnetic turbulence.  I have termed this mechanism an ‘inverse Fermi acceleration.’  The decrease in CR intensity then follows directly from an application of Liouville’s theorem.

S.F. Singer, “Cosmic Ray Time Variations Produced by Deceleration in Interplanetary Space.” Nuovo Cimento 8, Suppl. II, 334 – 341, 1958.  Laster, H., A.M. Lenchek and S.F. Singer. “Interplanetary Gas Cloud Modulation of Cosmic Rays.” Bull. Am. Phys. Soc., 5, 259, 1960:  J. Phys. Soc. Japan, 17, Suppl. AII, 583, 1962

I am not aware of any direct measurement of this shift in the primary CR energy spectrum but a comparison of CR neutron monitor data  with those of mu-mesons does suggest confirmation.

Best

Fred

and Terry Sloan responds:

Dear Fred,

Thank you for your e mail. I interleave some comments.

Regards, Terry.

Dear Benny

Some corrections to the letter from Terry Sloan:

1. First, a minor point: The solar particle stream (“wind”) does not ‘generate’ a mag field. A somewhat turbulent solar surface field is ‘frozen in ‘ (a la Alfven) into the stream and decays only slowly

—–> I agree that it is more complicated than my simple heuristic explanation.

2. The ‘deflection’ argument may be intuitive but doesn’t really work logically. For every CR particle aimed at the Earth that’s deflected away, there will be one not aimed at the Earth that’s deflected to hit the Earth

——> I agree with this point for very high energy CR but at low energy, where the deflections are larger, particles undergo sling shot effects and more are lost than are gained. Hence the influence of solar activity.

3. The 11-yr cycle seen in CR intensity (and other solar-modulated CR variations) depend on deceleration (i e, a shift in the energy spectrum) produced by scattering of CR from expanding regions of magnetic turbulence. I have termed this mechanism an ‘inverse Fermi acceleration.’ The decrease in CR intensity then follows directly from an application of Liouville’s theorem.

—-> Again I agree that it is more complicated than my simple argument. However, I do not like this argument since the particles themselves are not decelerated. However, I agree that there is a shift in the spectrum.

S.F. Singer, “Cosmic Ray Time Variations Produced by Deceleration in Interplanetary Space.” Nuovo Cimento 8, Suppl. II, 334 – 341, 1958. Laster, H., A.M. Lenchek and S.F. Singer. “Interplanetary Gas Cloud Modulation of Cosmic Rays.” Bull. Am. Phys. Soc., 5, 259, 1960: J. Phys. Soc. Japan, 17, Suppl. AII, 583, 1962

I am not aware of any direct measurement of this shift in the primary CR energy spectrum but a comparison of CR neutron monitor data with those of mu-mesons does suggest confirmation.

—-> There is another greater effect on muons which is the energy threshold when the CR interact in the atmosphere. Pion multiplicities grow with energy. So muons tend to be produced by much more energetic CRs than those which produce the majority of the neutron monitor counts. Hence they are less susceptible to variations in the solar activity.

I’m not quite convinced with Fred’s statement that the position is neutral for cosmic ray deflection in the case that the protons have the same energy as the solar wind or less, but I’ll have to do more calculations on that point.

Update: S. Fred Singer replies

Terry

You may be right about the last point (the muons).

It would help if someone could measure the shift in energy spectrum over the solar cycle — or during Forbush decreases.

Just the latitude variation of total counts, measured from a satellite.

Can you get such data?

Best

Fred

Written by John A

August 17, 2009 at 2:04 pm

Posted in Svensmark

Terry Sloan replies on the Svensmark process

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Terry Sloan has written his thoughts on my calculations as to whether Svensmark’s process should cause sufficient deflection towards the Earth’s magnetic poles to be measureable:

The word ‘funnelling’ is very misleading. I do not know where it  came from – it was not from me. Forget it – here is the real story.

Cosmic rays from outside the solar system come with a very wide spectrum of energies from zero up 10^20 eV. The intensity falls off  very rapidly as the energy increases (roughly proportional to E^-2.7, i.e. one over E to 2.7 th power, where E is energy). At low energies they are mainly protons with about 20% Helium and then smaller amounts of heavier nuclei.

The sun pours pours out streams of charged particles as well and this is called the solar wind. These are usually at low energies (much below 10^9 eV). These streams of particles form electric currents which generate a magnetic field. This field is still finite out to very  large distances (up to 100 times the distance from sun to Earth – this is 100 AU, 1 AU=astronomical unit = sun Earth distance)

Imagine a cosmic ray coming from outside the solar system in the direction of the Earth. If the ray has very high energy it is hardly deflected and so can hit the Earth.

However, at lower energies it feels  a finite deflection and it does not need much of a deflection at a large distance from the Earth to miss the Earth.

Now the solar wind is stronger at the peak of the sun spot number in its 11 year cycle than at the minimum activity. Hence less of the lower  energy cosmic rays hit the Earth during solar maximum.

Have a look at a cosmic ray monitor (see http://ulysses.sr.unh.edu/NeutronMonitor/Misc/neutron2.html and follow the links on there). You can clearly see the 11 year solar cycle on the cosmic ray rate. The rate varies by 15-20% from solar max to solar min.

The cosmic ray has not yet finished. If it manages to evade the magnetic field generated by the solar wind it then has to get through the Earth’s magnetic field. Near the Earth’s equator this field tends to be about perpendicular to a particle hitting the Earth. So again low energy particles are deflected away and do not hit the Earth.

Near the poles a cosmic ray aiming at the Earth travels parallel to these field lines which then have very little effect (remember that the force on a charged particle moving in a magnetic field is perpendicular to the velocity and the field).

Hence you see less 11 year modulation on the cosmic ray rate near the equator but a larger effect near the poles. Have a look at the Climax (somewhere near the pole) and Huancayo (close to the Equator) monitors (do a Google on them) and you will see what I mean.

I hope this helps.

Regards,

Terry Sloan.

Here are plots of Climax and Huancayo that Terry was referring to:

Written by John A

August 17, 2009 at 1:55 pm

Posted in Svensmark