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Global 3-D modeling of atmospheric ozone in the free troposphere and the stratosphere with emphasis on midlatitude regions. Final report

Description: The authors have used several global chemical/transport models (1) to study the contribution of various physical, chemical, and dynamical processes to the budget of mid-latitude ozone in the stratosphere and troposphere; (2) to analyze the potential mechanisms which are responsible for the observed ozone perturbations at mid-latitudes of the lower stratosphere and in the upper troposphere; (3) to calculate potential changes in atmospheric ozone response to anthropogenic changes (e.g., emission of industrially manufactured CFCs, CO, and NO{sub x}) and to natural perturbations (e.g., volcanic eruptions and biomass burning); and (4) to estimate the impact of these changes on the radiative forcing to the climate system and on the level of UV-B radiation at the surface.
Date: March 1, 1999
Creator: Brasseur, G.; Tie, X. & Walters, S.
Partner: UNT Libraries Government Documents Department

Global 3-d modeling of atmospheric ozone in the free troposphere and the stratosphere with emphasis on midlatitude regions. Final report, July 1, 1994--June 30, 1997

Description: The objective of this research is to use global chemical-transport models to study the chemical and dynamical processes that affect midlatitude stratospheric ozone and to quantify the budget of tropospheric ozone. Four models will be improved and used: (1) a new version of the two-dimensional chemical-radiative-dynamical model with microphysical process of sulfate aerosols and polar stratospheric clouds (PSCs), and heterogeneous conversions on the surfaces of sulfate aerosols and PSCs; (2) the stratospheric version of three-dimensional off-line chemical-transport model (STARS) with a relatively high horizontal resolution (2.8 degree in latitudes) with a microphysical formation of PSCs; (3) the tropospheric version of three-dimensional off-line chemical-transport model (MOZART) with details in the surface emissions and hydrocarbon reactions to estimate the tropospheric ozone budget and perturbations; (4) the intermediate model of the global and annual evolution of species (IMAGES) with a detailed chemical reactions but relatively lower resolutions. Model results will be compared with available data.
Date: December 1, 1997
Creator: Brasseur, G.; Erickson, D.; Tie, X. & Walter, S.
Partner: UNT Libraries Government Documents Department

Summary of research for FY-1995: Progress report

Description: The object of this proposal is to study the reduction in mid-latitude stratospheric ozone and to estimate the budget of tropospheric ozone. The product of this proposal include: (1) the estimation of dilution of air masses processed by polar stratospheric clouds inside the polar vortex during winter; and (2) the destruction of ozone via heterogeneous reactions on the surface of aerosol particles which are present at all latitudes, especially after large volcanic eruptions such as Mt. Pinatubo; (3) to quantify photochemical production and destruction of O{sub 3} in the free troposphere; (4) to quantify export of ozone from polluted to remote regions, and (5) to quantify cross-tropopause exchanges of O{sub 3} and other species. The approach of this proposal is to use and to improve the two-dimensional and three-dimensional global chemical/dynamical models.
Date: March 1, 1996
Creator: Brasseur, G.; Erickson, D.; Tie, X.X. & Walters, S.
Partner: UNT Libraries Government Documents Department

GRI methane chemistry program review meeting

Description: Methane is an important greenhouse gas which affects the atmosphere directly by the absorption and re-emission of infrared radiation as well as indirectly, through chemical interactions. Emissions of several important greenhouse gases (GHGS) including methane are increasing, mainly due to human activity. Higher concentrations of these gases in the atmosphere are projected to cause a decrease in the amount of infrared radiation escaping to space, and a subsequent warming of global climate. It is therefore vital to understand not only the causes of increased production of methane and other GHGS, but the effect of higher GHG concentrations on climate, and the possibilities for reductions of these emissions. In GRI-UIUC methane project, the role of methane in climate change and greenhouse gas abatement strategies is being studied using several distinct approaches. First, a detailed treatment of the mechanisms controlling each important methane source and sink, and hence the atmospheric concentration of methane, is being developed for use with the UIUC Integrated Science Assessment Model. The focus of this study is to resolve the factors which determine methane emissions and removal, including human population, land use, energy demand, global temperature, and regional concentrations of the hydroxyl radical, carbon monoxide, nitrous oxides, non-methane hydrocarbons, water vapor, tropospheric and stratospheric ozone.
Date: February 1, 1997
Creator: Dignon, J.; Grant, K.; Grossman, A.; Wuebles, D.; Brasseur, G.; Madronich, S. et al.
Partner: UNT Libraries Government Documents Department