Skip to main content
. Author manuscript; available in PMC: 2020 Sep 8.
Published in final edited form as: J Clim. 2017 Jul 27;30(17):6851–6872. doi: 10.1175/jcli-d-16-0613.1

Fig. 5.

Fig. 5.

Monthly and regional variations of surface PM2.5 (μg m−3) from both EPA-AQS (gray dashed) and IMPROVE (red dashed) networks compared with MERRA-2 PM2.5 sampled at IMPROVE sites (red solid) and EPA sites (black solid) located in the U.S. northwestern (NW), north-central (NC), northeastern (NE), southwestern (SW), south-central (SC), and southeastern (SE) regions over the period 2003–12. Vertical bars are the standard deviations of monthly values calculated from years 2003 to 2012 for the model; shaded area is the same for the observations. The encompassed map shows the location of EPA-AQS (black) and IMPROVE (red) stations and the dividing black lines indicate the six regions considered.