HR: 1340h
AN: A13D-0968    [Abstracts]
TI: Northern and Southern hemispheric monthly averages of nitrous oxide and ozone: A ``one-year climatology'' derived from ILAS/ILAS-II observations
AU: * Khosrawi, F
EM: farahnaz.khosrawi@itm.su.se
AF: Institute of Applied Environmental Science, Frescativägen 54, Stockholm, 106 91 Sweden
AU: * Khosrawi, F
EM: farahnaz.khosrawi@itm.su.se
AF: Forschungszentrum Jülich, Leo-Brandt-Str., J 52425 Germany
AU: M R
EM: ro.mueller@fz-juelich.de
AF: Forschungszentrum Jülich, Leo-Brandt-Str., J 52425 Germany
AU: Proffitt, M H
EM: m.proffitt@wmo.int
AF: World Meteorological Organisatio, 7 bis, Avenue de la Paix Case Postal 2300, Geneva, 1211 Switzerland
AU: Nakajima, H
EM: hide@nies.go.jp
AF: National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, 305-8506 Japan
AB: Correlations of ozone (O₃) and nitrous oxide (N₂O) have been suggested as a tool for validating photochemical models and as a reference for estimating high latitude ozone loss. However, so far no data set is available that provides a good temporal coverage throughout all seasons. Here, we combine measurements from the Improved Limb Atmospheric Spectrometers (ILAS/ILAS-II) to derive an O₃/N₂O climatology for the high latitude regions in the Northern and Southern Hemisphere for each month of the year, thus providing a complete seasonal cycle. ILAS operated for 8 months in 1996/1997 and ILAS-II for 7 month in 2003. From the ILAS-II measurements the months that are not available from ILAS are covered. The ILAS/ILAS-II correlations of ozone vs. nitrous oxide are organized monthly in both hemispheres by partitioning these data into equal bins of altitude or potential temperature. The resulting families of curves allow to separate ozone changes due to photochemistry from those due to transport. The combined ILAS/ILAS-II data set corroborates earlier findings that the families of O₃/N₂O curves are separated and generally do not cross and further that the separation is much clearer for the potential temperature binning than for the altitude binning. The seasonal cycle of O₃/N₂O distributions in the Northern and Southern Hemisphere high latitudes is found to be rather different. In the Southern Hemisphere O₃/N₂O distributions are influenced by the strong chemical ozone loss in the Antarctic vortex and a much longer duration of the polar vortex. In the Northern Hemisphere, diabatic descent is much more pronounced. Solely during the setup phase of the polar vortex the N₂O/O₃ distributions in the two hemispheres are rather similar.The data set derived here provides a tool which can be used for the validation of simulations of the seasonal cylce of ozone high latitudes by photochemical models.
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005