Continuous measurements of NO_x, NO_y, and canister samples for a wide variety of VOC species were analyzed to better understand the VOC/NO_x ratios observed from different source types during TexAQS 2000 using data collected with the Baylor University Twin Otter aircraft. The continuous measurements were integrated over the sampling period of the VOC canisters for this analysis. Different source types were identified through analysis of the surface wind fields observed during selected flights and geographic location of the aircraft relative to the plumes of various major source types.