Jasper Kirkby of CERN has published a new paper examining the potential link between cosmic rays and climate.
The paper concludes:
Numerous palaeoclimatic observations, covering a wide range of time scales, suggest that galactic cosmic ray variability is associated with climate change. The quality and diversity of the observations make it difficult to dismiss them merely as chance associations. But is the GCR flux directly affecting the climate or merely acting as a proxy for variations of the solar irradiance or a spectral component such as UV? Here, there is some palaeoclimatic evidence for associations of the climate with geomagnetic and galactic modulations of the GCR flux, which, if confirmed, point to a direct GCR-climate forcing. Moreover, numerous studies have reported meteorological responses to short-term changes of cosmic rays or the global electrical current, which are unambiguously associated with ionising particle radiation.
Cosmic ray forcing of the climate could in principle operate on all time scales from days to hundreds of millions of years, reflecting the characteristic time scales for changes in the Sun’s magnetic activity, Earth’s magnetic field, and the galactic environment of the solar system. Moreover the climate forcing would act simultaneously, and with the same sign, across the globe. This would both allow a large climatic response from a relatively small forcing and also give rise to simultaneous regional climate responses without any clear teleconnection path. The most persuasive palaeoclimatic evidence for solar/GCR forcing involves sub-orbital (centennial and millennial) climate variability over the Holocene, for which there is no established forcing agent at present. Increased GCR flux appears to be associated with a cooler climate, a southerly shift of the ITCZ (Inter Tropical Convergence Zone) and a weakening of the monsoon; and decreased GCR flux is associated with a warmer climate, a northerly shift of the ITCZ and a strengthening of the monsoon (increased rainfall). The influence on the ITCZ may imply significant changes of upper tropospheric water vapour in the tropics and sub-tropics, potentially affecting both long-wave absorption and the availability of water vapour for cirrus clouds.
The most likely mechanism for a putative GCR-climate forcing is an influence of ionisation on clouds, as suggested by satellite observations and supported by theoretical and modelling studies. The satellite data suggest that decreased GCR flux is associated with decreased low altitude clouds, which are known to exert globally a net radiative cooling effect. Studies of Forbush decreases and solar proton events further suggest that decreased GCR flux may reduce high altitude (polar stratospheric) clouds in the Antarctic. Candidate microphysical processes include ion-induced nucleation of new aerosols from trace condensable vapours, and the formation of relatively highly charged aerosols and cloud droplets at cloud boundaries, which may enhance the formation of ice particles in clouds and affect the collision efficiencies of aerosols with cloud droplets. Although recent observations support the presence of ioninduced nucleation of new aerosols in the atmosphere, the possible contribution of such new particles to changes in the number of cloud condensation nuclei remains an open question. Furthermore, the parts of the globe and atmosphere that would be expected to be the most climatically sensitive to such processes are unknown, although they are likely to involve regions of low existing CCN concentrations.
Despite these uncertainties, the question of whether, and to what extent, the climate is influenced by solar and cosmic ray variability remains central to our understanding of the anthropogenic contribution to present climate change. Real progress on the cosmic ray-climate question will require a physical mechanism to be established, or else ruled out. With new experiments planned or underway, such as the CLOUD facility at CERN, there are good prospects that we will have some firm answers to this question within the next few years.
Kirkby, J. 2008. Cosmic rays and climate. Surveys in Geophysics 28: 333-375.
[...] paper by Dr Kirby was first discussed here in a blog post by Paul Biggs on May 21 this year. I’ve only just properly discovered it – [...]
Louis, yes rays, beams, winds, etc are really only descriptions and are not causal like electric currents or are we talking electric waves?
Svensmark uses particular data and i'm just wondering about where he gets this accurate data on low-level cloudiness and "cosmic ray" intensity?
The idea of inter planetary current flows and the possibility of inter galactic electrical current brings to mind an article I read some years ago about an engineer for RCA radio coming up with a study on radio propagation and the position of the planets. In the 1930’s most overseas telephone traffic was handled by short wave radio. Radio engineers were obsessed with radio propagation like ham radio operators (I being one of them) are today. Needless to say his ideas were rejected by almost everybody, calling it a sort of radio astrology. This article has stuck with me and this discussion has provided the possibility of a mechanism for this to take place.
I have tried to find a copy of this paper, but have never been able to find one. His name was Nelson or Nielson and other than the article in this Ham Radio magazine I have not seen any reference to it.
John M Reynolds
It is indeed off topic, much so.
However, I seem to have thwarted it, for the time being, and let's get back to topic.
Now, I am not sure about this but Piers Corbyn has been succussfuly predicting weather on solar factors. I'm not sure whether he factors in cosmic rays in his modelling, (and there are no theories on this either).
Perhaps ask him?
Keiran and others,
Thanks for your kind comments.
In terms of Wes George, that issue is water under the bridge and we should leave it there.
In terms of cosmic rays, (generally protons), think in terms of electric currents, not mysterious rays.
As far as galactic cosmic rays modulating cloudiness most people would be aware that Svensmark puts forward some lab experiments and graphs indicating a fair degree of correlation of cosmic-ray intensities with low-level cloud cover. Plus he seems to show some evidence that the earth’s climate responds to variations in cloud cover that predicts the contrary behaviour of Antarctica.
To my way of thinking the cosmic-ray and cloud-forcing hypothesis needs more work but is quite interesting because it raises a number of questions. The first question for me is the data that Svensmark uses. Where do we get this accurate data on low-level cloudiness and how and where is the data for cosmic ray intensity?
Louis, i was just responding to Wes's comment "your radical flat universe, with no time space continuum." He has certainly set out to target you for posing some "radical" questions and thoughts. Very much his agenda i'd say ... he hasn't so much as attempted a response to anything i have simply put to him that relate to his paradoxical ideas. e.g. When you see paradoxes you also get the associated erroneous assumptions. Wes's ego seems to have a problem with infinity but for myself from when i was about thirteen years old i have humbly understood infinity as the very reason for the existence of the universe.
Back to galactic cosmic rays.
When attempting to understand solar influences on earth's climate, i feel we need to understand that sunnyboy interacts with our planet in a wide variety of complex ways and almost certainly that all these factors are influencing our lovely planet, even though we don't fully understand how. e.g. It is not only the cyclic warming and cooling of the sun, but others that we have little understanding of like changes with cosmic rays, changes in the solar spectrum towards greater ultra-violet radiation when compared with visible or infra-red light ... also geomagnetic activity which has doubled and been in an uptrend for over 100 years. What does this mean?