HR: 0800h
AN: A51A-0746    [Abstracts]
TI: Ozone Feedback Effects on the Quasi-Biennial Oscillation of Zonal Wind in the Equatorial Stratosphere
AU: * Shibata, K
EM: kshibata@mri-jma.go.jp
AF: Meteorological Research Institute, 1-1 Nagamine, Tsukuba, 305-0052 Japan
AU: Deushi, M
EM: mdeushi@mri-jma.go.jp
AF: Meteorological Research Institute, 1-1 Nagamine, Tsukuba, 305-0052 Japan
AB: Feedback effect of ozone on the quasi-biennial oscillation (QBO) of zonal wind is investigated with a 3-D chemical transport model of Meteorological Research Institute, MJ98-CTM. The dynamical module (MJ98) is a spectral global model of T42 truncation with 68 layers extending from the surface to 0.01 hPa (about 80 km), wherein the vertical spacing is 500m in the stratosphere. To reproduce QBO in zonal wind, Hines gravity wave (GW) drag is incorporated with enhanced GW source in the tropics. Further, the horizontal diffusion is weakened to 180 hrs at the maximum wavenumber of 42 in the middle atmosphere, while a conventional value of 18 hrs is used in the troposphere. MJ98 successfully reproduces a zonal wind QBO with a period of about 27 months in the equatorial stratosphere without trend, though the strength is somewhat smaller than observations. To the dynamical module of MJ98, a chemical transport module (CTM) is coupled and the radiative heating effect of ozone QBO on the dynamical QBO is explored. The CTM module treats 34 long-lived species including 7 families, and 15 short-lived species with 79 gas phase reactions, 34 photochemical reactions and 9 heterogeneous reactions on polar stratospheric clouds and sulfate aerosols. Transport scheme is a flux form semi-Lagrangian type in the vertical and, at once, a simple semi-Lagrangian type in the horizontal with cubic interpolation. Two runs are made for more than 10 years: one is a non-interactive ozone run and the other is an interactive ozone run. It is found that the interactive ozone elongates the QBO period from 27 months to about 4 years. Detail analysis of the ozone feedback effects on QBO is made in the presentation.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 3319 General circulation
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting