Cosmic Ray/Weather Link Passes Experimental Test

Svensmark’s cosmic ray theory of clouds and global warming looks to be confirmed

Researchers in the Technical University of Denmark (DTU) are hard on the trail of a previously unknown molecular process that helps commonplace clouds to form. Tests in a large and highly instrumented reaction chamber in Lyngby, called SKY2, demonstrate that an existing chemical theory is misleading.

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.

Simulating what could happen in the atmosphere, the DTU’s SKY2 experiment shows molecular clusters (red dots) failing to grow enough to provide significant numbers of “cloud condensation nuclei” (CCN) of more than 50 nanometres in diameter. This is what existing theories predict. But when the air in the chamber is exposed to ionizing rays that simulate the effect of cosmic rays, the clusters (blue dots) grow much more vigorously to the sizes suitable for helping water droplets to form and make clouds. (A nanometre is a millionth of a millimetre.)

Nature also seems to be doing this experiment for us in the upcoming years.  The current sunspot cycle, #24, is proving to be a dud, as the sun's magnetic field and is declining to unheard of levels since the age of modern instrumentation.  As the solar magnetic field declines, more cosmic rays will strike the earth's atmosphere.  If this indeed produces more clouds, the earth will likely experience another cooling period like the Maunder and Dalton sunspot minimums.