Figure 11.
Seasonal cycles from urban and rural sites in the Washington, DC, and Baltimore region with at least 1 year of observations. Midafternoon (13:00–18:00 LST) daily averages are detrended using a linear fit to the annual trend at Mauna Loa (for CO2) and the global average (for CH4) (data from NOAA/ESRL) and then averaged monthly. Rural sites include TMD, SFD, and BUC; urban sites are ARL, NDC, JES, HAL, NEB, and NWB. Shading indicates 1 standard deviation of the averages from all the sites.