The aerosols data base from LITMS

(Laboratory for Information Technologies and Mathematical Simulation)

FIRST PART : Complex indices of refraction computed aerosol integrated optical properties
Table 1. Complex indices of refraction  m=p-iq of basic aerosol components

Basic aerosol constituent File(*)
Water (liquid) h2o.ref
Dust dust_l.ref
75 % H2SO4 h2so4.ref
Sea salt ocean.ref
Soot soot.ref
Volcanic ash volc_ash.ref
Water-soluble particles w_s.ref

(*) See headers of data files for format and content description

Table 2. Integrated optical properties(*) (extinction coefficient, single scattering albedo, asymmetry factor) of principal aerosol models

Aerosol model Basic aerosol constituent Volume relative concentration (%) Particle number relative concentration(**) File
Continental Dust-Like

Water-Soluble

Soot

 70

29

1

 2.26278 10-6

9.37437 10-1

6.25607 10-2

 s_cont.dat
Urban Water-Soluble

Soot

Dust-Like

 61

22

17

 5.88931 10-1

4.11069 10-1

1.64128 10-7

 s_urb.dat
Maritime Ocean

Water-Soluble

 95

5

 4.29942 10-4

9.99573 10-1

 s_mar.dat
Stratospheric 75%  H2SO4 100 1.0 s_h2so4.dat
Volcanic Volcanic Ash 100 1.0 s_volc.dat
Cloud Water 100 1.0 s_cloud.dat
  • (*) See headers of data files for format and content description
  • (**) For each aerosol model, the total sum of basic aerosol
    constituent concentrations has to be equal to 1 (dimensionless)

Table 3. Integrated optical properties (extinction coefficient, single scattering albedo, asymmetry factor)

Basic aerosol constituent File(*)
Dust-like particles s_dust.dat
Water-soluble particles s_w_s.dat
Soot s_soot.dat
Oceanic s_oc.dat

(*) See headers of data files for format and content
description
SECOND PART : Computation of the integrated optical properties of atmospheric aerosols: the AERCOMP FORTRAN code

The FORTRAN code AERCOMP (UNIX version) allows calculations of the above basic aerosol integrated optical properties (see Table 3) for more complex, composite aerosol models with user’s selected concentrations of constituents, in the same format as the *.dat files of Tables 2,3:

The data are written in six column- format as a following:

  1. line number;
  2. wavelength (in microns);
  3. the extinction coefficient (in km-1);
  4. single scattering albedo;
  5. asymmetry factor;
  6. normalization factor.

To download and install this software:

  • click here
  • save rublev.tar file into a directory on the hard disk
  • restore the compressed files with the command tar xvf rublev.tar
  • compile aercomp.f file with a FORTRAN compiler (e.g. f77 aercomp.f -o aercomp)

Description and use of the AERCOMP program.

The aerocomp.f program uses the following files:

  • i_*.dat binary files (Float, 4 bytes) with the optical properties of the 7 basic aerosol constituents listed in Table 2 (column 2) and with values of the phase function at 204 angles (in degres) from the ug_204.dat (from rublev.tar file).
    Table 4 summarizes the involved constituents (column 1) and the corresponding i_*.dat files (column 2).

Table 4. Basic aerosol constituents and related i_*.dat binary files used by the AEROCOMP code.

Basic aerosol constituent i_*.dat file
Dust-like i_dust.dat
Water-soluble i_w_s.dat
Soot i_soot.dat
Ocean i_oc.dat
75% H2SO4 i_h2so4.dat
Volcanic Ash i_volc.dat
Water (cloud) i_cloud.dat

 

The i_*.dat binary files delivered with the AEROCOMP software are 2D arrays (61columns x 210 lines) of real numbers (Float, 4 bytes) stored as disk files. They comprise the following data:

  • The first line contains ordered numbers from 1 to 61;
  • The second line (i.e. the records number from 62 to 122) contains the values of 61 irregular spaced wavelengths from 0.2 to 40 micrometers;
  • The third line contains the extinction coefficients, in km-1, for a particle number concentration N=1 particle per
    cm3, at the wavelengths given in line two;
  • The fourth line contains the single scattering albedo values at the above mentioned wavelengths;
  • The fifth line contains the asymmetry factors at the above mentioned wavelengths;
  • The sixth line contains the normalization factors at the above mentioned wavelengths;
  • The remaining 204 lines from 7 to 210 contain the phase function values at the above mentioned 61 wavelengths and at 204 angles (irregulary spaced from 0 to 180 degrees) stored in the ug_204.dat file: e.g. line 7 contains the phase function values at the first angle value of the ug_204.dat file (0 degree), line 8 contains the phase function values at 0.02 degrees (second value of the ug_204.dat file), etc…

The detailed description and the explicit formulas for the above listed (see Table 2) optical parameters can be found in Rublev, 1994

  • inp_comp.dat file: control parameters file to be set up by the user.
  • lm_sh.dat file: file with wavelengths (in micrometers) used for
    calculations of the basic aerosol constituents integrated optical properties
    according to the Mie theory. The user should not change this file!
  • ug_204.dat file: file with the angles values (in degrees) used for
    calculation of the phase function of the basic aerosol constituents. The
    user should not change this file!

The inp_comp.dat file delivered with this software package as an example, allows the computations of  integral optical characteristics of the continental aerosol model given in Table 2, storing them into the s_cont1.dat (ASCII) and i_cont1.dat (binary) files.
The control parameters file inp_comp.dat contains N+1 blocs, where N is the number of the basic aerosol constituents (Nmax=7) in an aerosol of interest.

The s_cont1.dat file contains the same integrated optical properties (extinction coefficient, single scattering albedo, asymmetry factor, and normalization factor)and has the same format
as the *.dat files from Table 3.

The i_cont1.dat file has the same binary format as the above mentioned the i_*.dat files (only it corresponds to 2D array with 13 columns and 187 lines- see parameters in Table 5).

The user should set up the parameters of an aerosol of interest filling up the fields of the inp_comp.dat file  and then run the executable aercomp.
Note that the binary file i_cont1.dat can be used as an input file for aercomp.fprogram in order to compose more complex aerosol models.

Table 5, given as an example, describes the inp_comp.dat file corresponding to an aerosol mixture including three basic constituents: i.e., dust-like, water-soluble, and soot particles,
with the respective particles number concentrations (in particles per cm3):
2.26278 10-6, 0.937437, and 0.0625607. In column 1 are the input and output parameters for computations. Column 2 gives  identification of column 1 data in the aercomp.f program, and column 3 describes column 1 data.

The integrated optical parameters will be computed at the wavelengths and at the angles stored in the lm_exam.dat and ug_181.dat files respectively. Note, that the wavelength and angle values stored in these files have to be within the same interval (i.e. from 0.2 to 40 microns for wavelengths and from 0 to 180 degrees for angles) as those of the lm_sh.dat and ug_204.dat files respectively. The program uses a linear interpolation algorithm to calculate the integrated optical properties at the wavelengths and angles stored in the lm_exam.dat and ug_181.dat files.

Table 5. Example of the inp_comp.dat file delivered with this software package(*)

3  
n_comp      –  NUMBER OF BASIC AEROSOL CONSTITUENTS13 
n_m0      –  NUMBER OF
WAVELENGTHS TO BE USED IN CALCULATIONS(**)lm_exam.dat   name_m0    –  FILE
FOR SELECTED WAVELENGTHS181
n_ug0          –  TOTAL
NUMBER OF SELECTED ANGULAR MESH POINTS(***)

ug_181.dat      name_ug0  –
FILE WITH ANGULAR MESH POINTS

s_cont1.dat     s_dat
– OUTPUT FILE FOR EXTINCTION COEFFICIENTS

i_cont1.dat      i_dat
– OUTPUT FILE FOR PHASE FUNCTION

********************************************************************************************************

61
n_m       –
NUMBER OF WAVELENGTHS TO BE USED IN CALCULATIONS

i_dust.dat  
nc_ind    – INPUT FILE FOR BASIC AEROSOL
CONSTITUENT PARAMETERS

2.26278E-6       si
–  PARTICLE NUMBER CONCENTRATION (particle cm-3)

lm_sh.dat 
name_m    – FILE OF WAVELENGTHS

204
n_ug           –
TOTAL NUMBER OF ANGULAR MESH POINTS

ug_204.dat         name_ug
–  FILE OF ANGULAR MESH POINTS

********************************************************************************************************

61  
n_m         –
NUMBER OF WAVELENGTHS TO BE USED IN CALCULATIONS

i_w_s.dat  
nc_ind    –  INPUT FILE
FOR BASIC AEROSOL CONSTITUENT PARAMETERS

0.937437
si
–  PARTICLE NUMBER CONCENTRATION (particle cm-3)

lm_sh.dat 
name_m      – FILE OF WAVELENGTHS

204   
n_ug           –
TOTAL NUMBER OF ANGULAR MESH POINTS

ug_204.dat  
name_ug     –  FILE OF THE ANGULAR MESH POINTS

********************************************************************************************************

61
n_m        – NUMBER
OF WAVELENGTHS TO BE USED IN CALCULATIONS

i_soot.dat  
nc_ind   – INPUT FILE FOR BASIC AEROSOL CONSTITUENT
PARAMETERS

0.0625607 
si
–  PARTICLE NUMBER CONCENTRATION (particle cm-3)

lm_sh.dat 
name_m   – FILE OF WAVELENGTHS

204 
n_ug          –  TOTAL
NUMBER OF ANGULAR MESH POINTS

ug_204.dat  
name_ug   –  FILE OF THE ANGULAR MESH POINTS

******************************************************************************************************
  • (*) Parameters in italic can
    be changed by the user for own calculations. Parameters in bold should
    not be changed!
  • (**) The parameter n_m0 should
    be less or equal to the total number of records in the lm_exam.dat file.
  • (***) The parameter n_ug0 should
    be less or equal to the total number of records in the ug_181.dat file.