Boxplots of seasonal hydrocarbon ratio changes. Shown are benzene-to-acetylene (a) and isopentane-to-acetylene (b) ratios observed at the Karnes county monitor as compared to several other studies. The solid error bars shown in both graphs are based on results from Ammoura et al. (2014), Coll et al. (2010), and Warneke et al. (2007); the individual data squares are based on results from Pang et al. (2015). DOI: https://doi.org/10.1525/elementa.289.f5