Open AccessSimulation of ozone and other chemical species using a Center for Climate System Research/National Institute for Environmental Studies atmospheric GCM with coupled stratospheric chemistry
Author(s) -
Takigawa Masayuki,
Takahashi Masaaki,
Akiyoshi Hideharu
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1998jd100105
Subject(s) - stratosphere , atmospheric sciences , northern hemisphere , tropopause , ozone , middle latitudes , climatology , southern hemisphere , environmental science , zonal and meridional , ozone layer , troposphere , latitude , ozone depletion , atmospheric model , atmosphere (unit) , equinox , atmospheric chemistry , polar vortex , geology , physics , meteorology , geodesy
A new middle‐atmosphere general circulation model that includes the photochemistry for ozone and other chemical species (19 photolysis and 52 chemical reactions) has been constructed. The horizontal spectral resolution is T21 (about a 600 km horizontal grid spacing) with 30 layers in the vertical. Preliminary results from over 10 years of model integration are presented. The distributions of long‐lived species, such as N 2 O, are rather similar to those of satellite observations in a climatological sense, although the sharp meridional gradient around 30° latitude is not well simulated in the model stratosphere. Neither is the double peak structure that occurs during equinox periods well reproduced. This result is consistent with the fact that the westerly phase of the semiannual oscillation is weak in this model. This may be due to the coarse resolution of the model. The seasonal evolution of the ozone column abundance is quite realistic, although the model slightly underestimates total tropical ozone. The model also underestimates ozone amounts around the equatorial tropopause. The February midlatitude number density of OH in the model upper stratosphere is about 1.8 × 10 7 cm −3 , which is slightly less than that observed. The horizontal distributions of short‐lived species, such as NO, suggest a reasonable model diurnal variation. The model has a cold bias of about 25 K in the lower stratospheric Northern Hemisphere winter and 5 K in the Southern Hemisphere winter. The model residual mean vertical velocity in the equatorial lower stratosphere is too weak (about 0.1 mm/s) during the Northern Hemisphere winter, compared with the observed (about 0.4 mm/s), while the model temperature around the equatorial tropopause is cooler than that observed.