Assessing The Synergistic Impact Of Anthropogenic And Biogenic Emissions On Air Pollution Using Novel High-Sensitivity, Real-Time Monitors For Fundamental CarbonylsEPA Grant Number: R835138
Title: Assessing The Synergistic Impact Of Anthropogenic And Biogenic Emissions On Air Pollution Using Novel High-Sensitivity, Real-Time Monitors For Fundamental Carbonyls
Investigators: Keutsch, Frank N
Institution: University of Wisconsin Madison
EPA Project Officer: Chung, Serena
Project Period: February 1, 2012 through January 31, 2015 (Extended to January 31, 2016)
Project Amount: $250,000
RFA: Developing the Next Generation of Air Quality Measurement Technology (2011) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air
The goal of this project is to demonstrate instrumentation that will allow the use of novel high time resolution monitoring data sets as new metrics to determine the contribution of anthropogenic and biogenic emissions to ozone and organic aerosol (PM). We will demonstrate that the proposed novel instrumentation can obtain long-term, low-maintenance and accurate measurements of key carbonyl-containing compounds such as formaldehyde and glyoxal, consistent with the requirements for instrumentation employed in monitoring networks. The project will validate this approach by collecting a yearlong dataset at the Horicon National Core Monitoring Station, a rural site in Wisconsin that is part of the EPA Region 5 Ambient Monitoring Network. An objective of this work is to develop the ratio and absolute concentration of monitored glyoxal/formaldehyde as a metric of the contribution of biogenic and anthropogenic volatile organic compounds (VOCs) to atmospheric oxidation. This metric will allow distinction between the direct contribution of anthropogenic VOCs and the anthropogenic impact on biogenic VOC oxidation (resulting O3 and PM via NOx), an emerging issue in air quality control, in particular for PM. In addition, these data will be compared with WRF-CMAQ model output to evaluate and improve the representation of atmospheric oxidative chemistry in models, thereby helping to provide strategies to control air quality related to O3 and PM.
Measurements of glyoxal and formaldehyde will be conducted with two field-proven instruments, a formaldehyde laser-induced fluorescence (LIF) and a α-dicarbonyl laser-induced phosphorescence (LIP) instrument, both of which are the first designs of their kind for atmospheric monitoring. These instruments have vastly superior sensitivity (< 10 pptv/min LOD) compared to other methods, are highly selective and accurate, and can acquire data faster than 1 Hz if required. Analysis of the unique long-term datasets from these instruments, together with available short-term datasets from different urban and rural locations and measurements of NOx, O3, and VOCs, will reveal both the degree of contribution of anthropogenic VOCs to O3 and SOA production and the degree to which anthropogenic influence affects the oxidation rate of biogenic VOCs. Also, long-term analyses will improve the statistical robustness of the results. Results will be compared in detail to the output of WRF-CMAQ and sensitivity analyses of the model performed in order to evaluate and improve the representation of atmospheric oxidative chemistry in CMAQ.
The project will make available new types of portable sensors for obtaining high spatial and temporal resolution monitoring data and that these data can be made available in real-time, in particular for formaldehyde, an important toxic air pollutant. In addition, the project will provide a tool for locating formaldehyde emission sources and sources of VOC oxidation. The major expected result is the demonstration that monitoring and modeling glyoxal and formaldehyde concentrations and ratios provides a metric for quantifying anthropogenic influence on biogenic ozone and PM production. Overall, the project will thus provide a new tool for evaluating strategies for improving atmospheric chemical model performance, air quality and human health.