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Chemistry and Sources of Radicals and their Precursors in Houston
| Project Period: | 08/01/2008 - 08/31/2009 |
| Total Budget: | $294,400 |
| Sub-Contractors: | University of Houston
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Urban atmospheric chemistry is driven by radical species, which participate in various chemical reaction cycles that ultimately lead to the formation of ozone and particles. The dominant daytime radical species is the hydroxyl radical, OH, which is primarily formed through the photoysis of ozone, aldehydes, and nitrous acid. At night NO3 is typically the dominant radical species, responsible for the oxidation of hydrocarbons and the removal of NOx. An accurate quantitative description of radical chemistry, as well as the chemistry and sources of the various radical precursors, is essential to the understanding of air quality in Houston.
This project will study the chemistry and sources of radicals and their precursors in Houston. The first two tasks will provide new data on the direct emissions of formaldehyde, HONO, and other trace species from point sources in Houston. The first task will use an approach that measures the average emission rate of a large number of facilities in the ship channel area using two MAX-DOAS instruments over a period of a month. The second task will be the construction and deployment of a new portable Imaging-DOAS system to measure emissions from individual flares and other single point emission sources in Houston. The need of such measurements has been identified in the TERC Strategic Research Plan and the goal of the second task, as described in more detail below, is to considerably expand the knowledge on the average emissions of these gases from the Ship Channel area. The third task focuses on the improvement of our understanding of nocturnal chemical processes, such as nocturnal radical chemistry, the NOx budget, and HONO formation, using observations from the 2006 TRAMP experiment in Houston and a 1D chemical transport model. The results of this exercise will provide guidance for the improvement of the urban air quality model of the Houston area developed by the University of Houston. The last task of this research project will be a field experiment in Houston in April and May 2009, which aims to improve the available set of HONO observations. Two specific goals of this experiment are the inter-comparison of ambient HONO measurement techniques and the investigation of daytime HONO.
Related Categories
Below is a list of categories that this project belongs to.
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| Page Updated/Reviewed: 08/11/2008 11:41 AM |
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© 2005 - 2008 Texas Environmental Research Consortium
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