HR: 0800h
AN: SA41A-1039    [Abstracts]
TI: Evidence for a new Production Mechanism for the Singlet Delta State of Molecular Oxygen
AU: * Degenstein, D A
EM: doug.degenstein@usask.ca
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AU: Gattinger, R L
EM: gattinger@rogers.com
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AU: Lloyd, N D
EM: nick.lloyd@usask.ca
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AU: Bourassa, A E
EM: adam.bourassa@usask.ca
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AU: Wiensz, J T
EM: truitt.wiensz@usask.ca
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AU: Llewellyn, E J
EM: edward.llewellyn@usask.ca
AF: University of Saskatchewan, 116 Science Place, Saskatoon, Sk S7N 5E2 Canada
AB: The InfraRed Imager subsection of the OSIRIS instrument onboard the Odin spacecraft collects limb images of the Oxygen InfraRed Atmospheric band emissions at 1.27 microns. The dusk-dawn orbit of the Odin spacecraft means the evening twilight sector of the orbit is near the equator and as a result the tomographic retrieval technique used to process the InfraRed Imager data produces high resolution two-dimensional profiles of the singlet delta volume emission rate as the sun sets. For the times of year under consideration the actual sunset data extends from the equator to approximately 20 degrees latitude. Accepting the limitation that the satellite geometry means different solar zenith angles are viewed at different latitudes this work will use the InfraRed Imager measurements along with the accepted radiative lifetime and quenching coefficients to show that after the sun sets the singlet delta state of molecular oxygen does not decay as quickly as expected. If the accepted values are indeed correct the only explanation for the decrease in decay rate is that there is a production mechanism that has not been considered. The OSIRIS measurements indicate that this production mechanism is layered with a peak around 60 km.
DE: 0310 Airglow and aurora
DE: 0340 Middle atmosphere--composition and chemistry
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting