US EPA

Chemical-Transport Modeling of the Global Atmosphere Environmental Problems: Evaluations, Comparisons and Initial Studies

EPA Grant Number: R826384
Title: Chemical-Transport Modeling of the Global Atmosphere Environmental Problems: Evaluations, Comparisons and Initial Studies
Investigators: Wuebbles, Donald J. , Brasseur, Guy , Kotamarthi, V. Rao
Current Investigators: Wuebbles, Donald J. , Kotamarthi, V. Rao
Institution: University of Illinois at Urbana-Champaign , National Center for Atmospheric Research
Current Institution: University of Illinois at Urbana-Champaign
EPA Project Officer: Shapiro, Paul
Project Period: April 1, 1998 through March 31, 2001
Project Amount: $312,334
RFA: Exploratory Research - Environmental Chemistry (1997) RFA Text |  Recipients Lists
Research Category: Water , Land and Waste Management , Air , Engineering and Environmental Chemistry

Description:

There are many environmental issues and scientific problems where the capabilities of global scale three-dimensional models of the chemistry and physics of the troposphere and stratosphere will be required. However, up to this time, existing three-dimensional models have largely used a number of simplifying assumptions to make these models more computationally efficient. In the exploratory research project proposed, the University of Illinois will coordinate with the National Center for Atmospheric Research in the development, testing, and evaluating of a new three-dimensional chemical-transport model where such simplifications have been greatly minimized.

Approach:

After testing and evaluation of the model in comparison with available observations, initial research studies with the model will focus primarily on the oxidizing capacity of the atmosphere. Many compounds, including most of the replacement compounds being used and/or considered for CFCs, halons, and other controlled chemicals, are designed to react in the troposphere, largely with OH. Improved understanding of the oxidative capacity of the atmosphere is essential for estimating the lifetimes of these compounds correctly and to predict the fate of their degradation products in the troposphere. The sensitivity of model calculated tropical oxidant concentrations to perturbations, including biomass burning, will be investigated. The calculated oxidant field will be tested with an off-line simulation of CH3CCl3 and compared with observations. Sensitivity of model calculated lifetimes of short-lived (~ months) replacements to temporal and spatial variabilities of the source will be investigated.

Expected Results:

We expect as a result of this project to reduce the uncertainties in calculating the tropospheric lifetimes of such replacement compounds and to provide an improved understanding of the oxidizing capacity of the atmosphere and the changes that may be occurring to it.

Publications and Presentations:

Publications have been submitted on this project: View all 19 publications for this project

Journal Articles:

Journal Articles have been submitted on this project: View all 4 journal articles for this project

Supplemental Keywords:

global warming, nitrogen budget, semi-volatile organochlorines, RFA, Scientific Discipline, Air, Toxics, Ecology, Environmental Chemistry, Chemistry, climate change, CFCs, Engineering, Chemistry, & Physics, environmental monitoring, fate, global scale, atmospheric particles, global warming calculations, three dimensional transport model, global change, chemical transport modeling, organochlorides, chemical kinetics, halons, troposphere, nitrogen removal, oxidant, chemical transport models

Progress and Final Reports:

1999 Progress Report
Final Report