TERC - Project H074

The purpose of this research is to conduct measurements of volatile organic compounds (VOCs) using proton transfer reaction mass spectrometry (PTR-MS) at three locations in the Houston area (Deer Park, Bayland Park and Aldine) and VOCs and several nitrogen reservoir species using ion drift - chemical ionization mass spectrometry (ID-CIMS) at the University of Houston’s Moody Tower during TexAQS II - 2006.

We propose to conduct measurements of VOCs using PTR-MS during TexAQS II - 2006. Because of the its fast time-responding and high sensitivity, the PTR-MS is ideal for measurements of a suite VOCs. In situ VOC monitoring is essential to determine the abundance of VOCs that cause rapid ozone formation and high ozone concentrations in the Houston areas. The results will be essential for identification of emission sources and improvements of the current estimate of emission inventory and evaluation of simulations of ozone and its precursors using chemical transport models on the urban and regional scales. Our PTR-MS has been employed for measurements of pre-selected HRVOCs during TexAQS II – 2005; in particular, selected biogenic and anthropogenic VOCs and their degradation products have been successfully measured using the PTR-MS in conjunction with the 2005 – Southeast Texas Transport (Tetroon) Study (SETTS) and Northeast Texas Plume Study (NETPS).

The site for the Texas A&M PTR-MS will be located at TCEQ’s Aldine monitoring site. Results will be compared to measurements made by other PTR-MS instruments to determine the concentrations of various pollutants across the Houston area, during the August-September 2006 intensive field operation of TXAQS II. While this project will be carried out primarily by scientists from Battelle Northwest Laboratory (PNNL), Washington State University and Battelle Columbus Laboratories, we will join this term with our PTR-MS instrument. The purpose for this project is to deploy a set of PTR-MS at multiple levels of a skyscraper tall enough its upper levels are above the early morning PBL. The continuous set of PTR-MS observations will be supplemented by canister samples to measure species that cannot be measured by the PTR-MS (e.g. ethylene) and also to provide a check against the PTR-MS measurements.

We also propose to conduct measurements of VOCs and several nitrogen containing species using an ID-CIMS at the University of Houston’s Supersite Moody Tower during the TexAQS II – 06 intensive. VOCs, nitric acid (HNO3), and dinitrogen pentoxide (N2O5) will be measured in situ using ion-drift chemical ionization mass spectrometry (ID-CIMS). Measurements of the nitrogen containing compounds will be essential to elucidate the nighttime chemistry and quantify the impact of NOy on ozone formation on the subsequent day. The IDCIMS instrument will be complemented by a cavity ring down spectrometer (CRDS) developed by Dr. Simon North of TAMU, which is funded by the Texas Air Research Center (TARC) to conduct measurements of N2O5 and NO3 during TexAQS II at the same location.

Related Categories

Below is a list of categories that this project belongs to.