Further Analysis of NOx and O3 data, and the Acquisition, Installation and Laboratory Testing of the PM Equipment

Objective: * To add a PM monitor to the mobile NOx and ozone analyzers, and the weather monitoring unit built during the project performed in the last two years. * To analyze the data obtained in the previous research to elucidate the adequacy of CALINE4 in predicting the local NO2 concentrations near roadways and perform a sensitivity analysis on the model input variables, to investigate the reasons for the lack of fit observed under some conditions. Project Summary: A TEOM 1405-DF dichotomous ambient particulate monitor with a filter dynamics measurement system (FDMS) (Thermo Scientific, Franklin, MA) was purchased, received, set up in the laboratory and tested. To be taken to the measurement locations, this equipment needed to be put on a cart and it needed to be placed in a custom-made outside shelter with an air conditioning and heating unit. Considering the power requirements of the shelter, the PM equipment, O3 and NOx analyzers, the computer, and the weather monitoring instruments, a new generator with a higher power rating was, also, needed. The outside shelter was received in April 2012 and the cart in June 2012. The PM equipment was installed in the outside shelter and placed on the cart. It is ready to be started up and used in the on-site measurements. We also continued to work on improving the analysis of the NOx and O3 data for model validation. The results obtained on NO2 concentrations could be predicted reasonably well with CALINE4 for upwind receptors, but the difference between predicted and measured concentrations at downwind locations were substantial. Several factors were identified as possible reasons for these discrepancies and these were further investigated. For this purpose, a new set of data was acquired to evaluate the effect of averaging time on the validity of the model predictions. It was observed that the averaging time did not affect the results significantly. Subsequently, the model variables that are expected to affect the predicted concentrations were investigated by sensitivity analysis. It was concluded that the only plausible explanations for the observed results seem to be the effect of vegetation between the roadway and the receptors, and the limitation of the CALINE4 reaction scheme.