Research Article

Spatial and Temporal Trends in PM2.5 Organic and Elemental Carbon across the United States

Figure 5

2007–2010 regional monthly mean normalized (by annual mean) PM2.5 particulate organic matter (POM) for (a) IMPROVE and (b) CSN. Regions correspond to the Northeast (NE), Southeast (SE), Southwest (SW), and Northwest (NW).
367674.fig.005a
(a)
367674.fig.005b
(b)