scholarly journals Interannual Variations of the General Circulation and Polar Stratospheric Ozone Losses in a General Circulation Model.

2002 ◽  
Vol 80 (4B) ◽  
pp. 877-895 ◽  
Author(s):  
Shingo WATANABE ◽  
Toshihiko HIROOKA ◽  
Saburo MIYAHARA
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Stratospheric Ozone ◽  
Circulation Model ◽  
Interannual Variations

scholarly journals Development of the global atmospheric chemistry general circulation model BCC-GEOS-Chem v1.0: model description and evaluation

2020 ◽  
Vol 13 (9) ◽  
pp. 3817-3838
Author(s):  
Xiao Lu ◽  
Lin Zhang ◽  
Tongwen Wu ◽  
Michael S. Long ◽  
Jun Wang ◽  
...  
Keyword(s):  
General Circulation Model ◽  
Atmospheric Chemistry ◽  
Tropospheric Ozone ◽  
General Circulation ◽  
Climate Models ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Circulation Model ◽  
Satellite Observations ◽  
Model Description

Abstract. Chemistry plays an indispensable role in investigations of the atmosphere; however, many climate models either ignore or greatly simplify atmospheric chemistry, limiting both their accuracy and their scope. We present the development and evaluation of the online global atmospheric chemical model BCC-GEOS-Chem v1.0, coupling the GEOS-Chem chemical transport model (CTM) as an atmospheric chemistry component in the Beijing Climate Center atmospheric general circulation model (BCC-AGCM). The GEOS-Chem atmospheric chemistry component includes detailed tropospheric HOx–NOx–volatile organic compounds–ozone–bromine–aerosol chemistry and online dry and wet deposition schemes. We then demonstrate the new capabilities of BCC-GEOS-Chem v1.0 relative to the base BCC-AGCM model through a 3-year (2012–2014) simulation with anthropogenic emissions from the Community Emissions Data System (CEDS) used in the Coupled Model Intercomparison Project Phase 6 (CMIP6). The model captures well the spatial distributions and seasonal variations in tropospheric ozone, with seasonal mean biases of 0.4–2.2 ppbv at 700–400 hPa compared to satellite observations and within 10 ppbv at the surface to 500 hPa compared to global ozonesonde observations. The model has larger high-ozone biases over the tropics which we attribute to an overestimate of ozone chemical production. It underestimates ozone in the upper troposphere which is likely due either to the use of a simplified stratospheric ozone scheme or to biases in estimated stratosphere–troposphere exchange dynamics. The model diagnoses the global tropospheric ozone burden, OH concentration, and methane chemical lifetime to be 336 Tg, 1.16×106 molecule cm−3, and 8.3 years, respectively, which is consistent with recent multimodel assessments. The spatiotemporal distributions of NO2, CO, SO2, CH2O, and aerosol optical depth are generally in agreement with satellite observations. The development of BCC-GEOS-Chem v1.0 represents an important step for the development of fully coupled earth system models (ESMs) in China.

Assimilation of stratospheric ozone from MIPAS into a global general-circulation model: The September 2002 vortex split

2006 ◽  
Vol 132 (614) ◽  
pp. 231-257 ◽  
Author(s):  
A. J. Geer ◽  
C. Peubey ◽  
R. N. Bannister ◽  
R. Brugge ◽  
D. R. Jackson ◽  
...  
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Stratospheric Ozone ◽  
Circulation Model ◽  
Vortex Split

Numerical model studies of the effect of injected nitrogen oxides on stratospheric ozone

1977 ◽  
Vol 355 (1681) ◽  
pp. 267-299 ◽  
Keyword(s):  
Nitrogen Oxides ◽  
General Circulation Model ◽  
General Circulation ◽  
Stratospheric Ozone ◽  
Three Dimensional ◽  
Circulation Model ◽  
Reaction Rates ◽  
Transport Processes ◽  
One Dimensional ◽  
Dimensional Models

The work reported here has employed one-dimensional models, in which atmospheric transport is represented in combination with chemical kinetic mechanisms, to compute average vertical distributions of the minor constituents of the stratosphere as a function of time. Perturbation experiments simulating the effects of exhaust emissions, particularly nitrogen oxides and water vapour, from supersonic and subsonic aircraft fleets have been performed. The effect on stratospheric ozone of a possible four year variation in tropospheric N 2 O levels from 1966 to 1969 has also been investigated. Inert tracer studies from a three-dimensional tropospheric and stratospheric general circulation model have been used to examine specific limitations of the representation of transport processes in one-dimensional models. The inability of current one-dimensional models to represent counter gradient transport of minor gaseous constituents by the mean global circulation is a serious shortcoming in their use for studies of this type; the importance of mean motions in the general circulation is demonstrated by diagnostic data from a three-dimensional general circulation model, and by reference to the production of nitrogen oxides in thunderstorms. Further subjects studied were the effects on the calculated ozone reductions of using different profiles of vertical eddy diffusivity, diurnal and seasonal time dependence of the solar zenith angle in the photochemistry and temperature dependence of the chemical reaction rates. It was also found that the effects of injections from the supersonic and subsonic fleets were not linearly additive in the one-dimensional diffusive models used in this study. The optimum latitude at which to operate a one-dimensional model is discussed; for injected species with long atmospheric lifetimes a value of 34° is recommended for the Northern Hemisphere.

scholarly journals Results of an interactively coupled atmospheric chemistry – general circulation model: Comparison with observations

2001 ◽  
Vol 19 (4) ◽  
pp. 435-457 ◽  
Author(s):  
R. Hein ◽  
M. Dameris ◽  
C. Schnadt ◽  
C. Land ◽  
V. Grewe ◽  
...  
Keyword(s):  
General Circulation Model ◽  
Atmospheric Chemistry ◽  
General Circulation ◽  
Middle Atmosphere ◽  
Stratospheric Ozone ◽  
Circulation Model ◽  
Ozone Layer ◽  
The Arctic ◽  
Time Step ◽  
Stratospheric Dynamics

Abstract. The coupled climate-chemistry model ECHAM4.L39(DLR)/CHEM is presented which enables a simultaneous treatment of meteorology and atmospheric chemistry and their feedbacks. This is the first model which interactively combines a general circulation model with a chemical model, employing most of the important reactions and species necessary to describe the stratospheric and upper tropospheric ozone chemistry, and which is computationally fast enough to allow long-term integrations with currently available computer resources. This is possible as the model time-step used for the chemistry can be chosen as large as the integration time-step for the dynamics. Vertically the atmosphere is discretized by 39 levels from the surface up to the top layer which is centred at 10 hPa, with a relatively high vertical resolution of approximately 700 m near the extra-tropical tropopause. We present the results of a control simulation representing recent conditions (1990) and compare it to available observations. The focus is on investigations of stratospheric dynamics and chemistry relevant to describe the stratospheric ozone layer. ECHAM4.L39(DLR)/CHEM reproduces main features of stratospheric dynamics in the arctic vortex region, including stratospheric warming events. This constitutes a major improvement compared to earlier model versions. However, apparent shortcomings in Antarctic circulation and temperatures persist. The seasonal and interannual variability of the ozone layer is simulated in accordance with observations. Activation and deactivation of chlorine in the polar stratospheric vortices and their inter-hemispheric differences are reproduced. Considering methane oxidation as part of the dynamic-chemistry feedback results in an improved representation of the spatial distribution of stratospheric water vapour concentrations. The current model constitutes a powerful tool to investigate, for instance, the combined direct and indirect effects of anthropogenic trace gas emissions.Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry) – Meteorology and atmospheric dynamics (general circulation; middle atmosphere dynamics)

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