HR: 15:30h
AN: SA34A-01 INVITED     [Abstracts]
TI: Atomic Oxygen Variability in the Mesopause Region
AU: * Ward, W E
EM: wward@unb.ca
AF: Dept of Physics, UNiversity of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3 Canada
AU: Russell, J P
EM: jruss@unb.ca
AF: Dept of Physics, UNiversity of New Brunswick, P.O. Box 4400, Fredericton, NB E3B 5A3 Canada
AB: Atomic oxygen plays a major role in much of the chemistry in the mesopause region. Although the chemistry it is involved in is considered to be well understood, there still remain uncertainties about the oxygen budget and its role in heat budget. One of the factors associated with these uncertainties is how dynamics affects oxygen in this region. Observations from WINDII (Wind Imaging Interferometer) and analyses from the extended CMAM (Canadian Middle Atmosphere Model) suggest that large scale waves result in vertical parcel displacements whose distribution has a standard deviation of the order of 2 km in equatorial regions. The CMAM data suggests that this variability has a geographical dependence as a result of interference effects between various tidal components. The effect of this type of cycling depends on the height being considered. From WINDII results it appears that above ~85 km that oxygen remains a conserved tracer so the dynamics is primarily a complicating factor for interpreting observations. Below 85 km this cycling results in enhanced recombination relative to the recombination rate at the mean parcel height.
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
DE: 0342 Middle atmosphere--energy deposition
DE: 3384 Waves and tides
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly