Fig. 3.

Molar ratios of organic functional groups in the PMF factors for the atmospheric measurement campaigns listed in Table 1. Labels represent campaign abbreviations given in Table 1, and colors indicate the factor source types with combustion (salmon, circles have O/C < 0.4 and triangles have O/C > 0.4), terrestrial vegetation (jade, circles are biogenic and triangles are burning), and marine (cerulean, circles are O/C > 1 and triangles are O/C > 1), as in Fig. 1. The grayscale background indicates O/C by the scale given in the color bar.