First Results of the Study of Houston Atmospheric Radical Precursors (SHARP)

First results and a general overview of the chemical and meteorological conditions during the “Study of Houston Atmospheric Radical Processes (SHARP)” campaign intensive will be reported. Previous Houston air quality studies have identified major uncertainties in our understanding of the radical budget in Houston. These include primary emissions of nitrous acid (HONO) and formaldehyde (HCHO) from point and area sources including surface related processes for the formation of HONO. The SHARP campaign intensive was carried out between April and June 2009 to better quantify the OH sources to improve our understanding of springtime ozone (O3) chemistry in Houston. A more accurate description of ozone chemistry is also useful in developing efficient strategies to reduce pollution and to make recommendations to the Houston – SIP. The following is a list of some of the issues the SHARP project (and the related FLAIR, SOOT, TRENF subprojects) aim to address:

1) Are there direct emissions HCHO and HONO from flares and other industrial stacks as well as from mobile sources?

2) What are the surface-induced formation rates of HONO during both day and nighttime conditions?

3) What is the role of frontal passages and sea breeze in springtime Houston ozone events?

4) What is role of the residual layer on early morning rapid ozone production?

5) How well do the current state-of-the-art HONO instruments compare in an urban environment?

6) What is the role of ozonolysis of alkenes in the secondary formation of HCHO?