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| Titel |
Lessons from a Lifetime: O(1D) Emission in Ionospheric Modification |
| VerfasserIn |
Konstantinos S. Kalogerakis, Michael A. Glaros |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250047855
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| Zusammenfassung |
| The principal optical observable emission in ionospheric modification (IM) experiments is
the atomic oxygen red line at 630 nm, originating from the O(1D-3P ) transition. Because the
O(1D) atom has a long radiative lifetime, it is sensitive to collisional relaxation and an
observed decay faster than the radiative rate can be attributed to collisions with
atmospheric species. In recent work, we showed that in contrast to the common
practice of ignoring oxygen atoms in interpreting such observations in the past, O
atoms control the atomic oxygen red line emission between approximately 200 and
300 km [1]. Therefore, the observed O(1D) lifetime in IM experiments provides a
measure of the local O-atom density. An analysis of existing IM data yields good
agreement between observations and the MSIS model for altitudes above 250 km. In this
paper, we present analyses of observations from representative IM experiments
and of laboratory data investigating the relaxation of O(1D) by O(3P ), focusing
on the interpretation of the O(1D) emission’s temporal evolution at high and low
altitudes. We discuss the relevance to atmospheric observations and ionospheric heating
studies.
This work is supported by the U.S. National Science Foundation (NSF) under Grant
AGS-0937317. The participation of M. A. Glaros was supported by the NSF Research
Experiences for Undergraduates (REU) Program under Grant PHY-1002892.
[1] Kalogerakis, K. S., Slanger, T. G., Kendall, E. A., Pedersen, T. R., Kosch, M. J.,
Gustavsson, B., Rietveld, M. T., “Remote Oxygen Sensing by Ionospheric Excitation
(ROSIE),” Ann. Geophys., 27, 2183-2189 (2009). |
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