Atmospheric Modeling Group
Introduction to Atmospheric Chemistry Modeling
The atmosphere is a complex system.
Its behavior is determined by many physical, chemical and biological processes.
Because there are so many different processes the atmosphere is difficult to
understand. Many of these processes affecting the atmosphere are complicated,
interact with many other processes and can be highly nonlinear. This complexity
of the atmosphere makes it is necessary to apply computer models in order to
understand the natural behavior of the atmosphere including meteorological,
chemical and biological processes. A computer model is a miniature
representation of all relevant atmospheric processes and in addition to the
chemical and physical processes it requires detailed information on the emission,
deposition and transport of trace constituents.
Importance of models for science.
Atmospheric chemical modeling is even more important for understanding the
impact of air pollutant emissions on the chemical composition of the atmosphere
and the consequences on the environment, e.g. changes in the concentrations of
tropospheric ozone and toxic compounds as well as changes in regional acid
deposition and the regional and global climate. The study of urban and regional
ozone and other toxic air pollutants is extremely important because of the effects
on public health and the natural environment. Climate change has many possible
adverse effects on health, the economy and agriculture. Atmospheric chemistry
models are necessary for clarifying efficient and cost effective abatement
strategies to minimize the ecological effects of air pollution. As such the
atmospheric chemistry models support the interests of the local and national
government, industry and the international community.
Importance for industry and government.
Models validated though extensive testing are extremely valuable for use
by industry and government for planning purposes. Atmospheric models can
simulate the effects of proposed regulations or new air pollution control
approaches upon air quality. For example, models can be used to investigate
the effectiveness of proposed emissions reductions. Models are useful for
predicting the effect of proposed changes in emission rates upon the level of
air pollution. One of the key questions to be answered by models is the
determination if ozone formation is limited by the amount of available
hydrocarbons or NOx. This question can be investigated through simulations
by systematically varying the emissions rates of NOx and hydrocarbons for
typical meteorological conditions.
Linkages between atmospheric chemistry models and other models.
The atmospheric chemistry model results which include predictions of the
concentrations of ozone, toxic air pollutants, nitrogen compounds and
atmospheric acids are important sources of information for other kinds
of models. For example, atmospheric chemistry models can be linked with
ecosystem models or models of watersheds and wetlands. Linking atmospheric
chemistry models with other types of model is necessary to completely
determine the impact of atmospheric change on the environment.
Last updated December 24, 1998
Email: wstock@dri.edu
Post:
Division of Atmospheric Sciences
Desert Research Institute
2215 Raggio Parkway
Reno, NV 89512-1095
