RT Codes Comparison Project


2. Aerosol atmosphere Comparison


• Conditions of the comparison (RT3, MODTRAN, & SHARM vs. 6SV1) 


Table 2. Parameters of the aerosol models used in the comparison.

Model Urban-industrial and mixed Biomass burning Biomass burning
Location GSFC, Greenbelt, MD(1993-2000) Amazonian forest, Brazil (1993-1994), Bolivia (1998-1999) African savanna, Zambia (1995-2000)
Range of optical thickness τ; <τ> 0.1 ≤τ(440) ≤ 1.0<τ(440)>= 0.24 0.1 ≤τ(440) ≤ 3.0<τ(440)>= 0.74 0.1 ≤τ(440) ≤ 1.5<τ(440)>= 0.38
Real and imaginary parts of refractive index 0.2; 0.8 0.2; 0.8; 2.0 0.2; 0.8
Range of optical thickness τ; <τ> 1.41-0.03τ(440); 0.003 1.47;0.0093 1.51;0.021
SSA (412/440/670) 0.97/0.98/0.97 0.94/0.94/0.93 0.88/0.88/0.84
rVf (mm) 0.12+0.11τ(440) 0.14+0.013τ(440) 0.12+0.025τ(440)
sf (mm) 0.38 0.40 0.40
rVf (mm) 3.03+0.49τ(440) 3.27+0.58τ(440) 3.22+0.71τ(440)
sf (mm) 0.75 0.79 0.73
CVf (mm3/mm2) 0.15τ(440) 0.12τ(440) 0.12τ(440)
CVc (mm3/mm2) 0.01+0.04τ(440) 0.05τ(440) 0.09τ(440)

Reference: O. Dubovik, B. Holben, T. F. Eck, A. Smirnov, Y. J. Kaufman, M. D. King, D. Tanré, & I. Slutsker, Variability of absorption and optical properties of key aerosol types observed in worldwide locations, Journal of Atmospheric Sciences Vol. 59, Issue 3, p. 590-608, 2002.


Table 3. Sets of angles for the comparison.

VZA, deg. (view zenith angle) SZA, deg.(solar zenith angle) AZ, deg.(relative azimuth)
τ = 0.2 τ = 0.8 τ = 2.0
0.0000
11.4783
16.2602
23.0739
32.8599
43.9455
50.2082
58.6677
66.4218
71.3371
73.7398
78.4630
80.7931
84.2608
86.5602
88.8540
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
55.0
60.0
65.0
70.0
75.0
80.0
3.0
8.0
13.0
18.0
23.0
28.0
33.0
38.0
43.0
48.0
53.0
58.0
63.0
68.0
73.0
78.0
0.0
10.0
23.0709
45.0
58.6677
75.0
0.0
90.0
180.0

• Results of the comparison (RT3, MODTRAN, & SHARM vs. 6SV1) 


Figure 3. Some results of the comparison of RT3, MODTRAN, and SHARM for the UI aerosol model.


UI: Results. phase function for τ = 0.2; phase function for τ = 0.8;

AF: Results. phase function for τ = 0.2; phase function for τ = 0.8; phase function for τ = 2.0;

UI: Results. phase function for τ = 0.2; phase function for τ = 0.8;


• Conditions of the comparison (6SV1 vs.Monte Carlo) 


Some results of the comparison of RT3, MODTRAN, and SHARM for the UI aerosol model.


UI: λ= 412 nm, τaer = {0.2; 0.8}, SZA = {0.0-; 23.0-; 50.0-}, 2 x 1010 photons

AF: λ= 670 nm, τaer = {0.2; 0.8}, SZA = {0.0-; 23.0-; 50.0-}, 2 x 1010 photons

AS: λ= 440 nm, τaer = {0.2; 0.8}, SZA = {0.0-; 23.0-; 50.0-}, 2 x 1010 photons


• Results of the comparison (6SV1 vs.Monte Carlo) 


Figure 4. The results of the comparison of 6SV1 and Monte Carlo for the UI aerosol model.



The MC geometric configuration is explained in captions for Fig. 2 ('Results of the comparison (6SV1 vs. Monte Carlo)' in the 'Molecular atmosphere' section.


UI: Results.

AF: Results.

UI: Results.