UTA0057A ABSTRACT

Problem definition: Air quality monitoring and modeling studies indicate that regional ozone concentrations and regional transport of ozone will play a major role in determining whether the state's urban areas meet the new National Ambient Air Quality Standard (NAAQS) for ozone (with concentrations averaged over 8-hour intervals). However, current analyses of regional transport of air pollutants are largely semi-quantitative, and additional measurements and analyses are required to quantify the extent of regional ozone transport and to identify the sources of elevated regional ozone concentrations. A major focus of the next air quality field campaign in Texas (the second Texas Air Quality Study, TexAQS II) will be characterization of regional transport of air pollutants. This proposal describes a plan of modeling analyses and satellite data assimilation activities that will support the measurements program that will be implemented in TexAQS II.

Project Objectives The work described in this proposal will have the following objectives: Objective 1: Use gridded photochemical models (1) to estimate the extent of regional transport of ozone and other pollutants, and (2) to identify, key monitoring locations and aircraft flight paths that should be used in TexAQS II to characterize air- pollutant transport

Objective 2: Use aerosol optical depth data obtained from satellites (1) to estimate the extent of regional transport of air pollutants during historical episodes and (2) to estimate, in near real time, air pollutant transport trajectories

Proposed Research/Methodology

Objective 1 will be achieved by performing the following 3 tasks:

Task l.l: Use back trajectory calculations to qualitatively assess the potential magnitude of air pollutant transport into Texas cities from source regions within and outside of Texas.

Task 1.2 Use available air quality models to assess the extent of air pollutant transport and the source regions for transported ozone and compare the assessments to the dominant air pollutant transport meteorologies identified in Task 1.1

Task 1.3 Identify key aircraft flight paths that should be used in TexAQS II to characterize air pollutant transport

Objective 2 will be achieved by performing the following 3 tasks:

Task 2.1. Compare satellite-based observations with ground-based measurements for multi-day ozone events from 2000 to 2004

Task 2.2. Compare satellite-based observations with air pollutant concentration predictions of the modeled episode of 2000

Task 2.3. Generate near rear-tune aerosol products to support TexAQS II operations

Expected Benefits

The expected benefits of this program, beyond student training, will be (1) quantitative assessments of regional transport of air pollutants within and into Texas (2) the development of mechanisms for more rapid and comprehensive utilization of satellite data in photochemical model evaluation, (3) the development of mechanisms for more rapid use of satellite data in field study planning and (4) the development of mechanisms for more rapid and comprehensive utilization of satellite data as a complement to ground and aircraft monitoring.