During the TexAQS II campaign in summer 2006 (08/07/06 - 09/30/06) continuous online measurements of speciated PANs were carried out at the Moody Tower supersite and within the scope of the Houston Triangle experiment (09/13 – 09/29/06) at the Aldine site north of downtown Houston. Observations have shown that some days reveal distinct differences between both sites, whereas a few days reflect meteorological conditions when both sites were impacted by the same air mass.

Using CMAQ modeling this paper compares both sites in terms of the different VOC precursor matrices including data of C2 - C10 Volatile Organic Compounds (VOCs) obtained at the Moody Tower and VOC data from the TCEQ and Enhanced Industry Sponsored Monitoring auto-GC networks near the Ship Channel area and their impact on the partitioning of PAN species.