Date of Award

1-1-2012

Language

English

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College/School/Department

Department of Atmospheric and Environmental Sciences

Content Description

1 online resource (v, 52 pages) : illustrations (some color), color map.

Dissertation/Thesis Chair

James J Schwab

Committee Members

James J Schwab, Kenneth L Demerjian

Keywords

air pollution, evaluation, forecast, model performance, process analysis, regulation, Air quality, Air, Computer simulation, Model-based reasoning

Subject Categories

Atmospheric Sciences | Other Chemistry

Abstract

The University at Albany Air Quality Forecasting Modeling System (AQFMS) is a state-of-the-art model that generates reliable daily and "day-ahead" air quality forecasts for the Northeastern United States. The three major categories of processes which dictate regional air quality are production from emission sources, horizontal and vertical transport driven by the prevailing meteorology, and chemical transformations. The Advanced Research WRF (ARW) produces meteorological fields. The Sparse Matrix Operator for Kernel Emissions (SMOKE) processes available emission inventories for air quality modeling. The Comprehensive Air Quality Model with extension (CAMx) handles both chemical processes and the integration of ARW-WRF and SMOKE in devising separate quantitative contributions to pollutant concentrations from process categories. An AQFMS forecast, though indicative of the temporal and spatial changes in the ambient condition, does not tell us exactly how and why those changes occurred. High concentrations of criteria pollutants during "extreme" conditions could come about in many ways. Process analysis takes a step back in numerical procedures to showcase the partial contribution of 18 different processes to the predicted concentration. Area and point source make up the two emission source processes. Advection and diffusion through the west, east, south, north, bottom and top boundary make up the twelve horizontal and vertical transport processes. Gas phase and heterogeneous chemistry make up the two chemical transformation processes, with dry and wet deposition making up the two physio-chemical removal processes. A group of model defined "extreme" intra-day periods in a 12km by 12km grid spacing over The New York Botanical Gardens were evaluated for model performance at the surface and characterized by distinctive modes in which the aforementioned processes contribute to SO2, NOx and O3 concentrations in the vertical layers up to the first 4km of the model atmosphere. Trustworthy process features were highlighted for species and intra-day periods of satisfactory model performance. These features supplement AQFMS model forecasts of pollutant species concentrations for operational or regulatory pursuits with an enhanced understanding of model process interactions.

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