Non-methane hydrocarbons and CO during PACIFIC '93

Abstract Measurements of hydrocarbons and CO that were made during the summer of 1993 as part of the PACIFIC 93 field study in the Lower Fraser Valley, B.C., Canada are summarized. Good comparison between diverse data sets is observed. It appears that on basis of percent carbon (by weight) alkanes (excluding ethane) represent about 55%, alkenes 10%, aromatics (excluding benzene) 20%, and the biogenic hydrocarbon isoprene 3% of the total mass. Classification schemes that incorporate the different reactivity of the compounds suggest much less importance of the alkanes in favor of the alkenes and aromatics. About 10% of ozone production seems to be due to isoprene chemistry alone. Ozone is shown to increase during the day most likely due to photochemistry involving these hydrocarbons. Using hydrocarbon data from a location downwind of the city of Vancouver, and maximum ozone reactivity (MOR) factors derived by Carter (1991, EPA Report, 84pp.) it is estimated that the O 3 production rate in the first week of August 1993 might have been as high as 8 ppbv h −1 .