Saturday, May 28, 2011

Latest News From CERN CLOUD Experiment

In an earlier post I made mention of an experiment being conducted by CERN called CLOUD (‘cosmics leaving outdoor droplets’) which was an experiment designed to investigate the link between solar activity and the climate, to test the theory that cosmic rays spur the formation of particles in the air that nucleate clouds, in turn making skies cloudier and the planet cooler. They are doing this by using a particle beam from CERN as a stand-in for cosmic rays, and firing them through an ultra-clean steel chamber filled with select atmospheric gases, to see if and how particles that could nucleate clouds are formed.

Via Watts Up With That comes an update on where the experiment is currently at:

Update on the CERN CLOUD experiment

According to Nigel Calder’s Blog, CERN’s CLOUD experiment (testing Svensmarks’s cosmic-ray theory) shows a large enhancement of aerosol production and the results are due for release in 2 or 3 months’ time. There is a short Physics World interview with Jasper Kirkby which is worthwhile viewing and was published a couple of days ago…

Further down, we have some information from Bishop Hill liveblogging from the recent conference in Cambridge, UK where he makes notes on Q&A with Svensmark, plus a Josh livetoon.

From Physics World Head in a CLOUD:

In this special video report for CLOUD project leader Jasper Kirkby explains what his team is trying to achieve with its experiment. “We’re trying to understand what the connection is between a cosmic ray going through the atmosphere and the creation of so-called aerosol seeds – the seed for a cloud droplet or an ice particle,” Kirkby explains.

The CLOUD experiment recreates these cloud-forming processes by directing the beamline at CERN’s proton synchrotron into a stainless-steel chamber containing very pure air and selected trace gases.

One of the aims of the experiment is to discover details of cloud formation that could feed back into climate models. “Everybody agrees that clouds have a huge effect on the climate. But the understanding of how big that effect is is really very poorly known,” says Kirkby.

Bishop Hill liveblogs from Cambridge about Q&A with Henrik Svensmark:

  • Solar effect appears to be large. If exclude solar or regime change, then it makes anthropogenic look much bigger. These effects are not well covered by climate models.
  • Can effect be seen in climate? Use ocean heat content. Forcings = volcanoes, gcr, anthropogenic and a regime change in 1977. Solar effect ~1Wm-2, compares well with Shaviv. If remove solar effect left with apparent regime change in 1977. This can be seen in eg tropospheric temps.
  • Coronal mass ejections – decrease in gcrs at earth – forbush decrease. Is there an atmospheric response? Liquid water in clouds over oceans fall after forbush decrease. Ditto in low clouds etc. Aerosols ditto
  • Always lots of nucleation centres in atmosphere. Is this right?
  • Use trace gases in atmosph concentrations. Change amount of ionisation. See if you get more aerosol particles. SKY experiment.
  • Correlation between low clouds and GCRs – but need mechanism. Ions?
  • Discussion of LIA and solar. Solar irradiance too small to explain Need amplification mechanism – clouds.
  • Get correlations between eg stalagmite 18O and solar variability
  • One particle entering atmosphere generates shower of particles – incl ions which change chemistry
  • CRs accelerated by solar events – supernovae.

  • No comments:

    Post a Comment