OPAC is available on the anonymous ftp server of our computer center.
OPAC consists of ASCII files, which contain the optical properties of cloud and aerosol components, and of a FORTRAN program, which allows to handle the data. The FORTRAN program was tested to compile and run under DOS (Microsoft Fortran 5.0), Linux (GNU f2c converter), DEC Ultrix, HP Unix, and SunOS.
The whole package requires about 3.5 MB storage capacity.
To install OPAC, please extract the archive in an empty directory:
> gzip -d opac31a.tar.gz
> tar -xvf opac31a.tar
This will create 2 subdirectories and copy all files in their appropriate
places. The tar and gzip programs are also available for DOS (e.g. here).
If you did already install the Global Aerosol Data Set (GADS), you should install OPAC in the same directory, since GADS and OPAC use the same set of optical data of aerosol components, which are stored in the subdirectory optdat.
Now the FORTRAN program has to be compiled. On most UNIX computers, this requires something like:
> f77 opac.f -o opacIn this case, opac will be the name of the executable file. Some compilers give warning errors, which may be ignored. If you want to use a DOS computer, you must comment out lines 505-507 instead of 501-503 in opac.f. The "\" character is not understood by all compilers.
~ | 0% | 50% | 70% | 80% | 90% | 95% | 98% | 99% |
---|---|---|---|---|---|---|---|---|
insoluble | inso00 | - | - | - | - | - | - | - |
watersoluble | waso00 | waso50 | waso70 | waso80 | waso90 | waso95 | waso98 | waso99 |
soot | soot00 | - | - | - | - | - | - | - |
sea salt(acc. mode) | ssam00 | ssam50 | ssam70 | ssam80 | ssam90 | ssam95 | ssam98 | ssam99 |
sea salt(coa. mode) | sscm00 | sscm50 | sscm70 | sscm80 | sscm90 | sscm95 | sscm98 | sscm99 |
mineral (nuc. mode) | minm00 | - | - | - | - | - | - | - |
mineral (acc. mode) | miam00 | - | - | - | - | - | - | - |
mineral (coa. mode) | micm00 | - | - | - | - | - | - | - |
mineral (transported) | mitr00 | - | - | - | - | - | - | - |
sulfate droplets | suso00 | suso50 | suso70 | suso80 | suso90 | suso95 | suso98 | suso99 |
. | . | . | . | . | . | . | . | . |
stratus (continental) | stco00 | - | - | - | - | - | - | - |
stratus (maritime) | stma00 | - | - | - | - | - | - | - |
cumulus (cont., clean) | cucc00 | - | - | - | - | - | - | - |
cumulus (cont., poll.) | cucp00 | - | - | - | - | - | - | - |
cumulus (maritime) | cuma00 | - | - | - | - | - | - | - |
fog | fogr00 | - | - | - | - | - | - | - |
cirrus 1: -25°C | cir100 | - | - | - | - | - | - | - |
cirrus 2: -50°C | cir200 | - | - | - | - | - | - | - |
cirrus 3: -50°C (+ small particles) | cir300 | - | - | - | - | - | - | - |
There are 2 subdirectories in directory OPAC31:
The purpose of the program is to mix optical properties of single cloud or aerosol components (stored for 1 particle/cm^3) to optical properties of clouds or aerosol types, which may consist of several components. It is also possible to calculate optical properties which are not stored in the data base. These are for instance the optical depth, the extinction ratio (extinction coefficient divided by mass), or quantities which are integrated over the solar or terrestrial wavelength range.
Before starting the program, you have to edit an input file in order to define, which information you want to extract and calculate from the data base. Since the program prompts you for the name of the input file, you can use copies of the example and default input file opac.inp.
The program is started by typing opac in the subdirectory opac31, if you used the compiler command shown above.
The results are stored in the subdirectory result in files, whose names consist of the input file name, but with the extension .inp replaced by .out.
If you have the feeling, that the instructions given in this file, together with the explanations in the OPAC paper (Hess et al., 1998) are not sufficient, please let us know.