Project to Further Research, Develop, and Apply a New Air Pollution Modeling SystemEPA Grant Number: R823186
Title: Project to Further Research, Develop, and Apply a New Air Pollution Modeling System
Investigators: Jacobson, Mark Z.
Institution: Stanford University
EPA Project Officer: Shapiro, Paul
Project Period: September 1, 1995 through August 31, 1998
Project Amount: $325,701
RFA: Exploratory Research - Chemistry and Physics of Air (1995) RFA Text | Recipients Lists
Research Category: Air , Air Quality and Air Toxics , Engineering and Environmental Chemistry
Description:The primary goal of the project is to improve treatment of chemical and physical processes in a numerical air pollution model. Specifically, treatment of aerosol and cloud processes needs the most attention. A second important goal is to apply and test the revised air pollution model in Los Angeles and the San Francisco Bay Area.
To accomplish the first goal, new algorithms will be developed. For example, a numerical algorithm that simulates transfer of gases to multiple sizes of aerosols and cloud drops will be produced. The algorithm treats both condensation of a gas onto particles and dissolution of a gas into particles. The transfer algorithm will be coupled to a chemical equilibrium solver, which calculates internal particle composition. To treat particles of different sizes in different grid cells of a model, a new particle size bin structure is being developed. In this structure, size bin edges are fixed but size bin centers are allowed to fluctuate. Thus, the structure is called the moving-bin structure.
To partly accomplish the second goal, simulations of air pollution in the Los Angeles Basin will be carried out. Simulations results will be compared to data from the Southern California Air Quality Study (SCAQS) period of August 26 - 29, 1987. Model predictions will be compared to data for aerosol, gas, radiative, and meteorological parameters. One objective will be to study peak daytime surface solar radiation, night time temperatures, and overall temperatures in the presence and absence of aerosols in Los Angeles.
Finally, simulations of pollution in the San Francisco Bay Area are being planned. Such simulations require improved treatment of cloud processes. To that end, different numerical cloud algorithms are being tested, and one will be implemented into the air pollution model.