Conversion of Multicomponent Aerosol Size Distributions from Sectional to Modal Representations

Figures & data

FIG. 1 Sample aerosol distribution with two overlapping populations.

TABLE 1 Regression equations for total mass fit and multicomponent fit conversion methods

FIG. 2 Original sectional distribution and converted modal distributions created using arbitrary fit, total mass fit, and multicomponent fit methods.

TABLE 2 Parameters for sectional distribution shown in Figure 2

		Component mass in section (μ g m^− 3)
Section	Aerosol diameter range (μ m)	A	B	C
1	0.010–0.020	0.035	0.000	0.000
2	0.020–0.039	3.575	0.000	0.000
3	0.039–0.078	9.528	0.000	0.000
4	0.078–0.156	9.940	0.000	0.000
5	0.156–0.312	14.173	0.000	0.000
6	0.312–0.625	20.109	0.000	0.000
7	0.625–1.25	20.391	0.286	0.123
8	1.25–2.5	9.407	6.781	2.906
9	2.5–5	2.522	13.431	5.756
10	5–10	0.009	13.024	8.682
11	10–20	0.000	3.059	3.059
12	20–40	0.000	0.139	0.324

TABLE 3 Converted modal distribution parameters

	Converted distributions
	Arbitrary			Total mass			Multicomponent
Mode	1	2	3	1	2	3	1	2	3
Q k (μ g m^− 3)	13.1	84.1	50.0	—	125	23.7	21.0	69.0	57.6
σ k	1.70	2.00	2.20	—	5.34	1.47	1.84	2.34	1.94
d pk (μ m)	0.03	0.30	6.00	10^−9	0.74	5.68	0.07	0.59	5.04
x A (%)	100	88.0	5.1	—	71.5	4.5	99.9	99.8	0.0
x B (%)	0.0	8.4	59.3	—	18.4	59.9	0.00	0.2	63.8
x C (%)	0.0	3.6	35.6	—	10.1	35.6	0.1	0.00	36.2

FIG. 3 Original sectional distribution and sectional distributions created from converted modal distributions: (a) original sectional distribution, (b) arbitrary fit, (c) total mass fit, and (d) multicomponent fit.

FIG. 4 Original sectional distribution and sectional distributions created after 5 conversion cycles between sections and modes: (a) original sectional distribution, (b) arbitrary fit, (c) total mass fit, and (d) multicomponent fit.

FIG. 5 Modal distributions created using multicomponent fit method to convert original sectional distribution with (a) 12 sections, (b) 8 sections, and (c) 6 sections.