Fig. 2: Regional means of aerosol pH, gas–particle partitioning and cSIA sensitivities to precursor reductions (ΔcSIA/Δcp) from 2011 to 2020. | Nature Geoscience

Fig. 2: Regional means of aerosol pH, gas–particle partitioning and cSIA sensitivities to precursor reductions (ΔcSIA/Δcp) from 2011 to 2020.

From: Regime shift in secondary inorganic aerosol formation and nitrogen deposition in the rural United States

Fig. 2

The numbers of samples used to calculate the mean values for each region are listed in Supplementary Table 2. a–e, Simulated aerosol pH (black lines) in the Western (a), Central (b), Midwestern (c), Northeastern (d) and Southeastern (e) United States over time. f–j, Observed molar fractions ε of NO3T (cyan) and NH4T (brown) that partition into the particle phase (\({\varepsilon }_{{\rm{N}}{{\rm{O}}}_{3}^{-}}\) and \({\varepsilon }_{{\rm{N}}{{\rm{H}}}_{4}^{+}}\)) in the Western (f), Central (g), Midwestern (h), Northeastern (i) and Southeastern (j) United States over time. k–o, \({\Delta {c}_{{\rm{SIA}}}/\Delta {c}_{{\rm{S}}{{\rm{O}}}_{4}^{2-}}}\) (blue), \({\Delta {c}_{{\rm{SIA}}}/\Delta {c}_{{\rm{N}}{{\rm{O}}}_{3}^{{\rm{T}}}}}\) (green) and \({\Delta {c}_{{\rm{SIA}}}/\Delta {c}_{{\rm{N}}{{\rm{H}}}_{4}^{{\rm{T}}}}}\) (orange), simulated by reducing the corresponding precursors by 40% in the Western (k), Central (l), Midwestern (m), Northeastern (n) and Southeastern (o) United States over time. Vertical bars show the 25th and 75th percentiles of the corresponding values observed or simulated at locations within a region to illustrate regional variability.

Back to article page