CLOUD
Encyclopedia
Cosmics Leaving Outdoor Droplets or the CLOUD is an experimental facility being run at CERN
by Jasper Kirkby
to investigate the microphysics
between galactic cosmic rays (GCRs) and aerosols under controlled conditions. The experiment began operation in November 2009.
The experiment consists of a 3 m diameter aerosol chamber which is exposed to an adjustable particle beam that simulates GCRs at any altitude or latitude. The chamber is filled with air, water vapour, selected trace gases and can be operated at any temperature or pressure found in the atmosphere. UV illumination allows photolytic reaction. The chamber contains an electric field cage to control the drift of small ions and charged aerosols.
CERN posted a 2009 progress report on the CLOUD project. J. Kirkby (2009) reviews developments in the CERN CLOUD project and planned tests. He describes cloud nucleation mechanisms which appear energetically favourable and depend on GCRs.
On 24 August 2011, preliminary research published in the journal Nature showed there was a connection between Cosmic Rays and aerosol nucleation. Kirkby went on to say in the definitive CERN press Release "Ion‐enhancement is particularly pronounced in the cool temperatures of the mid‐troposphere and above, where CLOUD has found that sulphuric acid and water vapour can nucleate without the need for additional vapours. This result leaves open the possibility that cosmic rays could also influence climate. However, it is premature to conclude that cosmic rays have a significant influence on climate until the additional nucleating vapours have been identified, their ion enhancement measured, and the ultimate effects on clouds have been confirmed.
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...
by Jasper Kirkby
Jasper Kirkby
Jasper Kirkby is a British experimental particle physicist currently with CERN. He originated the idea for the Tau-Charm Factory, an accelerator now under construction as BEPC II in Beijing...
to investigate the microphysics
Particle physics
Particle physics is a branch of physics that studies the existence and interactions of particles that are the constituents of what is usually referred to as matter or radiation. In current understanding, particles are excitations of quantum fields and interact following their dynamics...
between galactic cosmic rays (GCRs) and aerosols under controlled conditions. The experiment began operation in November 2009.
The experiment consists of a 3 m diameter aerosol chamber which is exposed to an adjustable particle beam that simulates GCRs at any altitude or latitude. The chamber is filled with air, water vapour, selected trace gases and can be operated at any temperature or pressure found in the atmosphere. UV illumination allows photolytic reaction. The chamber contains an electric field cage to control the drift of small ions and charged aerosols.
CERN posted a 2009 progress report on the CLOUD project. J. Kirkby (2009) reviews developments in the CERN CLOUD project and planned tests. He describes cloud nucleation mechanisms which appear energetically favourable and depend on GCRs.
On 24 August 2011, preliminary research published in the journal Nature showed there was a connection between Cosmic Rays and aerosol nucleation. Kirkby went on to say in the definitive CERN press Release "Ion‐enhancement is particularly pronounced in the cool temperatures of the mid‐troposphere and above, where CLOUD has found that sulphuric acid and water vapour can nucleate without the need for additional vapours. This result leaves open the possibility that cosmic rays could also influence climate. However, it is premature to conclude that cosmic rays have a significant influence on climate until the additional nucleating vapours have been identified, their ion enhancement measured, and the ultimate effects on clouds have been confirmed.