Fig. 3. Spatial and temporal variation in organic aerosol (OA) sources and oxidative potential (OP).

Standardized monthly variation of OA sources and OP per unit volume of air, OP_v for five sites (a, c, e, g, i, k, m, o). The temporal anomaly (y-axis) for each sampling site was calculated from 9-12 (Jan), 8-9 (Feb), 5-6 (Mar), 5 (Apr), and 5 (May) daily samples as: ((absolute value – temporal site average (μ))/temporal site standard deviation (σ)). The colored solid lines and corresponding shaded area represent site-specific temporal anomaly and its ±1σ. A thick black dashed line represents the overall averaged spatial variation. The absolute values of the same parameters are shown as box whisker plots [line/box: median and 25^th-75^th percentile; upper and lower end of whisker: 10^th-90^th percentile] in (b, d, f, h, j, l, n, p).