Grantee Research Project Results

1999 Progress Report: Improved Photolytic Rate Measurements at PAMS Sites

EPA Grant Number: R826772
Title: Improved Photolytic Rate Measurements at PAMS Sites
Investigators: Rodgers, Michael O. , Pearson, James R.
Institution: Georgia Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: March 22, 1999 through March 21, 2001
Project Period Covered by this Report: March 22, 1999 through March 21, 2000
Project Amount: $168,930
RFA: Air Pollution Chemistry and Physics (1998) RFA Text |  Recipients Lists
Research Category: Air , Safer Chemicals

Objective:

The absence of reliable measurements of major UV photolytic rates coefficients has a significant and demonstrable effect on interpretive analysis of air quality field measurements regarding ozone and particulate matter chemistry. The major research objectives of this study are to develop, test, and validate a system to make these photolytic measurements and to evaluate the influence of these measurements on photochemical models using field measurement data from two Photochemical Assessment Monitoring Stations (PAMS) sites in Atlanta, Georgia.

Progress Summary:

The primary focus of efforts during the first year of this study was the design, fabrication, and laboratory testing of the UV photometer system to be field tested during the second year of the project. Mechanical and electrical design of the low-cost photometer system was completed in September 1999. Shortly thereafter, the commercially available components were acquired and custom parts were fabricated. The first of the two planned systems was completed in December 1999, and began laboratory testing and calibration in January 2000. Testing and calibration of this system was conducted in the first quarter of 2000. These laboratory tests revealed unexpected angular sensitivity problems and new input optics were acquired in March 2000 to correct these problems. This modified system was deployed to the Tucker, GA, PAMS field site in early April 2000 to begin field trials. Fabrication of the second photometer system began in March and deployment of this system is scheduled for June 2000, also at the Tucker site.

Future Activities:

During the second year of the project, the focus will shift to the field testing of the instruments and their intercomparison with other radiation measurement instrumentation. The primary focus will be on the comparison of photolytic rate estimates for J(O1D) and J(NO2) from the low-cost photometers with the Georgia Tech Air Quality Lab Airborne Chemical Actinometer. This latter system, developed for the NASA Pacific Exploratory Mission, provides direct measurements of both of these important photochemical rates and has been extensively intercompared with other research-grade instruments. Following the summer and fall field tests, additional laboratory studies will be conducted.

Journal Articles:

No journal articles submitted with this report: View all 1 publications for this project

Supplemental Keywords:

air, ambient air, ozone, global climate, stratospheric ozone, tropospheric, health effects, dose-response, nitrogen oxides, integrated assessment, engineering, measurement methods, monitoring, modeling, southeast, Georgia, GA, EPA Region 4., RFA, Air, Scientific Discipline, particulate matter, Environmental Chemistry, Engineering, Chemistry, & Physics, tropospheric ozone, Atmospheric Sciences, air toxics, hydrogen peroxide, Nitrogen dioxide, UV photolytic rate coefficients, air quality data, stratospheric ozone, air quality field measurements, risk assessment, PAMS sites, photolytic rate measurements, measurement methods, nitrogen dioxide (NO2), Formaldehyde, measure, particulate matter chemistry, ozone, field measurements

Relevant Websites:

http://www.aql.eas.gatech.edu

Progress and Final Reports:

Original Abstract

Final Report