67 Characteristics and Source Contribution of Particulate …
425
Fig. 67.2 Model
evaluation—comparison
between measure NH 3
partitioning ratio and model
estimated NH 3 partitioning
ratio
y = 0.92x + 0.06
R² = 0.81
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0.00
0.50
1.00
Modeled ε
Measured ε
JST
In general, all of those models showed relatively strong correlation between
aerosol pH and PM 2.5 sources by examine R
2 values, which is 0.52 in average.
In all four seasons, secondary sources such as ammonium sulfate and ammonium
bisulfate are significantly correlated to pH regardless of season. Ammonium sulfate
to pH sensitivity is about −0.08 in average and ammonium bisulfate to pH sensitivity
is about −0.18 in average. Considering sulfuric acid is a strong acid and ammonia is
a weak base, those species tend to contribute H
+ to lower the pH and make the aerosol
more acidic. Other factors showed seasonable pattern, which is mainly related to the
temperature and the variated chemical pathway under changed temperature.
References
1. A.G. Carlton, B.J. Turpin, Particle partitioning potential of organic compounds is highest in the
Eastern US and driven by anthropogenic water. Atmos. Chem. Phys. 13, 10203–10214 (2013).
https://doi.org/10.5194/acp-13-10203-2013
2. H. Guo, L. Xu, A. Bougiatioti, K.M. Cerully, S.L. Capps, J.R. Hite, A.G. Carlton, S.-H. Lee,
M.H. Bergin, N.L. Ng, A. Nenes, R.J. Weber, Fine-particle water and pH in the southeastern
United States. Atmo. Chem. Phys. 15, 5211–5228 (2015). https://doi.org/10.5194/acp-15-52112015
3. D.A. Hansen, E.S. Edgerton, B.E. Hartsell, J.J. Jansen, N. Kandasamy, G.M. Hidy, C.L.
Blanchard, The southeastern aerosol research and characterization study: part 1—overview.
J. Air Waste Manag. Assoc. 53, 1460–1471 (2003). https://doi.org/10.1080/10473289.2003.
10466318
4. C.J. Hennigan, J. Izumi, A.P. Sullivan, R.J. Weber, A. Nenes, A critical evaluation of proxy
methods used to estimate the acidity of atmospheric particles. Atmos. Chem. Phys. 15, 2775–
2790 (2015). https://doi.org/10.5194/acp-15-2775-2015
425
Fig. 67.2 Model
evaluation—comparison
between measure NH 3
partitioning ratio and model
estimated NH 3 partitioning
ratio
y = 0.92x + 0.06
R² = 0.81
0.00
0.20
0.40
0.60
0.80
1.00
1.20
0.00
0.50
1.00
Modeled ε
Measured ε
JST
In general, all of those models showed relatively strong correlation between
aerosol pH and PM 2.5 sources by examine R
2 values, which is 0.52 in average.
In all four seasons, secondary sources such as ammonium sulfate and ammonium
bisulfate are significantly correlated to pH regardless of season. Ammonium sulfate
to pH sensitivity is about −0.08 in average and ammonium bisulfate to pH sensitivity
is about −0.18 in average. Considering sulfuric acid is a strong acid and ammonia is
a weak base, those species tend to contribute H
+ to lower the pH and make the aerosol
more acidic. Other factors showed seasonable pattern, which is mainly related to the
temperature and the variated chemical pathway under changed temperature.
References
1. A.G. Carlton, B.J. Turpin, Particle partitioning potential of organic compounds is highest in the
Eastern US and driven by anthropogenic water. Atmos. Chem. Phys. 13, 10203–10214 (2013).
https://doi.org/10.5194/acp-13-10203-2013
2. H. Guo, L. Xu, A. Bougiatioti, K.M. Cerully, S.L. Capps, J.R. Hite, A.G. Carlton, S.-H. Lee,
M.H. Bergin, N.L. Ng, A. Nenes, R.J. Weber, Fine-particle water and pH in the southeastern
United States. Atmo. Chem. Phys. 15, 5211–5228 (2015). https://doi.org/10.5194/acp-15-52112015
3. D.A. Hansen, E.S. Edgerton, B.E. Hartsell, J.J. Jansen, N. Kandasamy, G.M. Hidy, C.L.
Blanchard, The southeastern aerosol research and characterization study: part 1—overview.
J. Air Waste Manag. Assoc. 53, 1460–1471 (2003). https://doi.org/10.1080/10473289.2003.
10466318
4. C.J. Hennigan, J. Izumi, A.P. Sullivan, R.J. Weber, A. Nenes, A critical evaluation of proxy
methods used to estimate the acidity of atmospheric particles. Atmos. Chem. Phys. 15, 2775–
2790 (2015). https://doi.org/10.5194/acp-15-2775-2015