HR: 11:50h
AN: A52B-06    [Abstracts]
TI: New Ion-Nucleation Mechanism Relevant for the Earths Atmosphere: Experimental Results
AU: * Svensmark, H
EM: hsv@dsri.dk
AF: Centre for Sun Climate research, Danish National Spacecentre, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AU: Pedersen, J P
EM: jopp@dsri.dk
AF: Centre for Sun Climate research, Danish National Spacecentre, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AU: Marsh, N
EM: ndm@dsri.dk
AF: Centre for Sun Climate research, Danish National Spacecentre, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AU: Enghoff, M B
EM: enghoff@dsri.dk
AF: Centre for Sun Climate research, Danish National Spacecentre, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AU: Uggerhoj, U
A52B-06 AF: Centre for Sun Climate research, Danish National Spacecentre, Juliane Maries Vej 30, Copenhagen, 2100 Denmark
AB: Resent studies have shown that the Earth's cloud cover is strongly correlated with the galactic cosmic ray flux. While this correlation is indicative of a possible physical connection, there is until now no confirmation that a physical mechanism exists. An experiment has therefore been set up in order to investigate the underlying microphysical processes.. Since any physical mechanism linking cosmic rays to clouds and climate is currently speculative, there have been various suggestions of the role atmospheric ions may play. These involve any one of a number of processes from the nucleation of aerosols up to the collection processes of cloud droplets. Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide, and water vapour suggest that the production rate of critical clusters is sensitive to ionisation. These results indicate that ions act as a catalyst in the initial chemical reactions leading to a significant production rate of stable sulphuric acid clusters. It is suggested that this nucleation process is a fundamental source of new aerosols in the Earths atmosphere, and could be the physical link between cosmic ray ionisation, cloud cover, and climate previously reported.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005