Stratospheric Chemistry and the Effect of Pollutants on Ozone

2000 ◽  
pp. 97-121
Author(s):  
R. A. Cox
Keyword(s):  
Stratospheric Chemistry

scholarly journals Evaluating Carbon Monoxide and Aerosol Optical Depth Simulations from CAM-Chem Using Satellite Observations

2021 ◽  
Vol 13 (11) ◽  
pp. 2231
Author(s):  
Débora Souza Alvim ◽  
Júlio Barboza Chiquetto ◽  
Monica Tais Siqueira D’Amelio ◽  
Bushra Khalid ◽  
Dirceu Luis Herdies ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
South America ◽  
Aerosol Optical Depth ◽  
Tropical Forests ◽  
Optical Depth ◽  
Eastern China ◽  
Central Africa ◽  
Central China ◽  
Stratospheric Chemistry ◽  
Tropical Areas

The scope of this work was to evaluate simulated carbon monoxide (CO) and aerosol optical depth (AOD) from the CAM-chem model against observed satellite data and additionally explore the empirical relationship of CO, AOD and fire radiative power (FRP). The simulated seasonal global concentrations of CO and AOD were compared, respectively, with the Measurements of Pollution in the Troposphere (MOPITT) and the Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite products for the period 2010–2014. The CAM-chem simulations were performed with two configurations: (A) tropospheric-only; and (B) tropospheric with stratospheric chemistry. Our results show that the spatial and seasonal distributions of CO and AOD were reasonably reproduced in both model configurations, except over central China, central Africa and equatorial regions of the Atlantic and Western Pacific, where CO was overestimated by 10–50 ppb. In configuration B, the positive CO bias was significantly reduced due to the inclusion of dry deposition, which was not present in the model configuration A. There was greater CO loss due to the chemical reactions, and shorter lifetime of the species with stratospheric chemistry. In summary, the model has difficulty in capturing the exact location of the maxima of the seasonal AOD distributions in both configurations. The AOD was overestimated by 0.1 to 0.25 over desert regions of Africa, the Middle East and Asia in both configurations, but the positive bias was even higher in the version with added stratospheric chemistry. By contrast, the AOD was underestimated over regions associated with anthropogenic activity, such as eastern China and northern India. Concerning the correlations between CO, AOD and FRP, high CO is found during March–April–May (MAM) in the Northern Hemisphere, mainly in China. In the Southern Hemisphere, high CO, AOD, and FRP values were found during August–September–October (ASO) due to fires, mostly in South America and South Africa. In South America, high AOD levels were observed over subtropical Brazil, Paraguay and Bolivia. Sparsely urbanized regions showed higher correlations between CO and FRP (0.7–0.9), particularly in tropical areas, such as the western Amazon region. There was a high correlation between CO and aerosols from biomass burning at the transition between the forest and savanna environments over eastern and central Africa. It was also possible to observe the transport of these pollutants from the African continent to the Brazilian coast. High correlations between CO and AOD were found over southeastern Asian countries, and correlations between FRP and AOD (0.5–0.8) were found over higher latitude regions such as Canada and Siberia as well as in tropical areas. Higher correlations between CO and FRP are observed in Savanna and Tropical forests (South America, Central America, Africa, Australia, and Southeast Asia) than FRP x AOD. In contrast, boreal forests in Russia, particularly in Siberia, show a higher FRP x AOD correlation than FRP x CO. In tropical forests, CO production is likely favored over aerosol, while in temperate forests, aerosol production is more than CO compared to tropical forests. On the east coast of the United States, the eastern border of the USA with Canada, eastern China, on the border between China, Russia, and Mongolia, and the border between North India and China, there is a high correlation of CO x AOD and a low correlation between FRP with both CO and AOD. Therefore, such emissions in these regions are not generated by forest fires but by industries and vehicular emissions since these are densely populated regions.

scholarly journals C-IFS-CB05-BASCOE: stratospheric chemistry in the Integrated Forecasting System of ECMWF

2016 ◽  
Vol 9 (9) ◽  
pp. 3071-3091 ◽  
Author(s):  
Vincent Huijnen ◽  
Johannes Flemming ◽  
Simon Chabrillat ◽  
Quentin Errera ◽  
Yves Christophe ◽  
...  
Keyword(s):  
Stratospheric Ozone ◽  
Transport Processes ◽  
Tropospheric Chemistry ◽  
Model Description ◽  
Stratospheric Chemistry ◽  
General Improvement ◽  
Forecasting System ◽  
The One ◽  
Stratospheric Composition ◽  
Chemistry Module

Abstract. We present a model description and benchmark evaluation of an extension of the tropospheric chemistry module in the Integrated Forecasting System (IFS) of the European Centre for Medium-Range Weather Forecasts (ECMWF) with stratospheric chemistry, referred to as C-IFS-CB05-BASCOE (for brevity here referred to as C-IFS-TS). The stratospheric chemistry originates from the one used in the Belgian Assimilation System for Chemical ObsErvations (BASCOE), and is here combined with the modified CB05 chemistry module for the troposphere as currently used operationally in the Copernicus Atmosphere Monitoring Service (CAMS). In our approach either the tropospheric or stratospheric chemistry module is applied, depending on the altitude of each individual grid box with respect to the tropopause. An evaluation of a 2.5-year long C-IFS-TS simulation with respect to various satellite retrieval products and in situ observations indicates good performance of the system in terms of stratospheric ozone, and a general improvement in terms of stratospheric composition compared to the C-IFS predecessor model version. Possible issues with transport processes in the stratosphere are identified. This marks a key step towards a chemistry module within IFS that encompasses both tropospheric and stratospheric composition, and could expand the CAMS analysis and forecast capabilities in the near future.

The Role of Chlorine in Stratospheric Chemistry

1996 ◽  
Vol 68 (9) ◽  
pp. 1749-1756 ◽  
Author(s):  
M. J. Molina
Keyword(s):  
Laboratory Experiments ◽  
Stratospheric Ozone ◽  
The Sun ◽  
Plastic Foam ◽  
Model Calculations ◽  
Stratospheric Chemistry ◽  
Blowing Agents ◽  
Stratospheric Ozone Layer ◽  
The Earth

The chlorofluorocarbons (CFCs) are industrialchemicals used as solvents, refrigerants, plastic foam blowing agents,etc. These compounds are eventually released to the environment; theyslowly drift into the stratosphere, where they decompose, initiatinga catalytic process involving chlorine free radicals and leading toozone destruction. The stratospheric ozone layer is important for theearth's energy budget, and it shields the surface of the earth fromultraviolet radiation from the sun. Very significant depletion of theozone layer has been observed in the spring months over Antarctica duringthe last 10-15 years. Laboratory experiments, model calculations andfield measurements, which include several aircraft expeditions, haveyielded a wealth of information which clearly points to the CFCs asthe main cause of this depletion.

STRATOSPHERIC CHEMISTRY AND COMPOSITION | Halogen Sources, Anthropogenic

2003 ◽  
pp. 2154-2162
Author(s):  
A. McCulloch ◽  
P.M. Midgley
Keyword(s):  
Stratospheric Chemistry

STRATOSPHERIC CHEMISTRY AND COMPOSITION | Halogens

2003 ◽  
pp. 2167-2174
Author(s):  
D. Toohey
Keyword(s):  
Stratospheric Chemistry

STRATOSPHERIC CHEMISTRY TOPICS | HOx

2015 ◽  
pp. 233-237
Author(s):  
T.F. Hanisco
Keyword(s):  
Stratospheric Chemistry

STRATOSPHERIC CHEMISTRY TOPICS | Hydrogen Budget

2015 ◽  
pp. 238-241
Author(s):  
J.E. Harries
Keyword(s):  
Stratospheric Chemistry

Stratospheric Chemistry

2016 ◽  
pp. 671-714
Author(s):  
Guido Visconti
Keyword(s):  
Stratospheric Chemistry

STRATOSPHERIC CHEMISTRY TOPICS | Halogens

2015 ◽  
pp. 215-220
Author(s):  
D. Toohey
Keyword(s):  
Stratospheric Chemistry

Stratospheric Chemistry

1991 ◽  
Vol 29 (S1) ◽  
pp. 12-24 ◽  
Author(s):  
WILLIAM H. BRUNE
Keyword(s):  
Stratospheric Chemistry
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