1.14 Comparing Models/Methods for Estimating Multi-pollutant Fine-Scale Air Quality Concentrations

摘要

Photochemical models are commonly used in regulatory and policy assessments to estimate pollutant concentrations and deposition of both inert and chemically reactive pollutants over large spatial scales. These models are generally run for horizontal grid resolutions of 36 and 12 km. However, several recent assessments have revealed the need for air quality predictions at resolutions finer than 12 km to resolve important local-scale gradients in pollutant concentrations. Given this need, we are undertaking a study to investigate several methods that can be used to obtain local-scale air quality concentrations. This study looks at the application and evaluation of a variety of models including CMAQ, CAMx and AERMOD. In addition, we will also evaluate the use of a new method called the Multiplicative Approach to the Hybrid Method (MAHM), which combines CMAQ and AERMOD predicted concentrations to generate local-scale air quality predictions. To do this, these models/methods are applied at ≤ 4 km resolution for both a winter and summer month in the same local area: Detroit, MI. The study looks at model/method performance of PM_(2.5), O_3, and several toxic pollutants by comparing modeled versus ambient measured concentrations. Resources for implementation of each model/method are also evaluated.