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| Titel |
Cosmic ray modulation of infra-red radiation in the atmosphere |
| VerfasserIn |
Karen Aplin, Michael Lockwood |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250074569
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| Zusammenfassung |
| Cosmic rays produce small charged clusters, known as molecular cluster ions, as they pass
through the lower atmosphere. Neutral molecular clusters such as dimers and complexes are
expected to make a small contribution to the radiative balance, but atmospheric
absorption by charged clusters has not hitherto been observed. Here we describe results
from an atmospheric experiment where a thermopile filter radiometer tuned to a
9.15μm absorption band, already associated with infra-red absorption of molecular
cluster ions, was used to monitor changes following events identified by a cosmic ray
telescope sensitive to high energy (>400MeV) particles, principally muons at the
surface. The change in longwave radiation in this absorption band due to molecular
cluster ions is 7 mWm-2 for each event recorded by the cosmic ray telescope.
The integrated atmospheric energy change for each event is 1.9 Jm-2, whereas
the energy density of a typical air shower (40m radius from a 10GeV primary) is
estimated to be 10-13 Jm-2, representing a direct amplification factor of 1012. This
infra-red absorption from molecular cluster-ions is expected to occur continuously
and globally, but calculations suggest that it has only a small effect on climate. |
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