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EcoAlert: "Milky Way's Cosmic Rays Have Direct Impact on Earth's Weather & Climate"




A fascinating new theory states that cosmic rays coming from our Milky Way Galaxy are directly involved in the Earth's weather and climate, according to Henrik Svensmark, lead author of the new study with the Technical University of Denmark. "In experiments over many years," he says, "we have shown that ionizing rays help to form small molecular clusters. Critics have argued that the clusters cannot grow large enough to affect cloud formation significantly. But our current research, of which the reported SKY2 experiment forms just one part, contradicts their conventional view. Now we want to close in on the details of the unexpected chemistry occurring in the air, at the end of the long journey that brought the cosmic rays here from exploded stars."

According to the theory, small clusters of molecules in the atmosphere have difficulty growing large enough to act as "cloud condensation nuclei" on which water droplets can gather to make our familiar low-altitude clouds. The SKY2 experiment shows that the growth of clusters is much more vigorous, provided ionizing rays -- gamma rays in the experiment or cosmic rays in the atmosphere -- are present to work their chemical magic.

Back in 1996 Danish physicists suggested that cosmic rays, energetic particles from space, are important in the formation of clouds. Since then, experiments in Copenhagen and elsewhere have demonstrated that cosmic rays actually help small clusters of molecules to form. But the cosmic-ray/cloud hypothesis seemed to run into a problem when numerical simulations of the prevailing chemical theory pointed to a failure of growth.

Fortunately the chemical theory could also be tested experimentally, as was done with SKY2, the chamber of which holds 8 cubic metres of air and traces of other gases. One series of experiments confirmed the unfavourable prediction that the new clusters would fail to grow sufficiently to be influential for clouds. But another series of experiments, using ionizing rays, gave a very different result, as can be seen in the accompanying figure.

The reactions going on in the air over our heads mostly involve commonplace molecules. During daylight hours, ultraviolet rays from the Sun encourage sulphur dioxide to react with ozone and water vapour to make sulphuric acid. The clusters of interest for cloud formation consist mainly of sulphuric acid and water molecules clumped together in very large numbers and they grow with the aid of other molecules.

Atmospheric chemists have assumed that when the clusters have gathered up the day's yield, they stop growing, and only a small fraction can become large enough to be meteorologically relevant. Yet in the SKY2 experiment, with natural cosmic rays and gamma-rays keeping the air in the chamber ionized, no such interruption occurs. This result suggests that another chemical process seems to be supplying the extra molecules needed to keep the clusters growing.

The Daily Galaxy via Technical University of Denmark and Physics Letters A


Svensmark's book, "The Chilling Stars", was a fascinating account of our porpoise like path through the arms of our galaxy and how changing amounts of radiation from space effects the weather by affecting cloud formation. Highly recommended.

An experiment at CERN last year validated the proposed mechanism by which variations in the Solar magnetic field affects the amount of interstellar gamma and x rays reaching Earth. This leads to changes in cloud formation, which in turn affects the amount of insolation entering Earths climate system. I should clarify that the CERN experiment validated that ionizing radiation led to an increase in nucleation particles.

I realize this little article is four years old now, however I just have to comment. First off I'm glad to see there are a number of scientist that are taking seriously the influence of how the Milky Way can affect our planets weather. Back in 1968 when I was in seventh grade we were covering our solar system and our weather, I asked the teacher about Galactic weather, being we orbit the sun and that gives us seasons, what about our solar system orbiting the center of the galaxy? I didn't really get laughed at, but poo pooed that that was pretty far fetched. Well I have never given up on the concept and truly feel we are experiencing the effects of Galactic influences on our weather today.

My comment on the article is, that there was only talk on the possibility of building cloud formations. What about particles, rays, and etc. that will inhibit cloud formation? We are seeing less rain and snow in places, that means less cloud formation. Less cloud formation affects our weather, no? So why is this article only talking about weather in reference of cloud formation?
Thank you,

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