# MIEAEROSOL_H2SO4¶

Calculate the optical properties of spherical sulphate aerosol particles. The class models the sulphates as a log-normal distribution. The user must provide an ISKClimatology of the log-normal parameters

• SKCLIMATOLOGY_LOGNORMAL_MODEWIDTH()

The log normal parameters climatology must be given to the MIEAEROSOL_H2S04 object using SetProperty( ‘SetParticleSizeClimatology’, object)

## Local Caching and Slow Performance¶

Calculation of optical properties of spherical particle distributions using Mie code is numerically intensive and will be quite slow. Consequently, the MIEAEROSOL_H2SO4 object cache optical properties for different aerosol parameters (mode radius, mode width and wavelength) on the local machine.

Note that the code will be slow each time the code encounters a new particle distribution or wavelength configuration. The location of the cache folder can be found on Windows and Linux machines at the registry entry HKEY_LOCAL_MACHINESOFTWAREUsask-ARGSkOpticalPropertiesMieAerosolAerosol_Cache_Directory.

## Example¶

optprop     = ISKOpticalProperty('MIEAEROSOL_H2SO4')
modeclimate = ISKClimatology('USERDEFINED_PROFILE');
modeclimate.SetPropertyArray('Heights', [0, 100000] );
modeclimate.SetPropertyUserDefined( SKCLIMATOLOGY_LOGNORMAL_MODEWIDTH(),          [1.6,  1.6]);
aerosol.SetProperty('SetParticleSizeClimatology', modeclimate);
msis = ISKClimatology('MSIS90');
mjd = 52393.3792987115;
location = [0.0, 0.0, 25000.0, mjd];
optprop.SetAtmosphericState( msis)
optprop.SetLocation(location)
[ok, abs, ext,sca] = optprop.CalculateCrossSections( 1.0E7/600.0, location );


## Properties¶

SetParticleSizeClimatology (object modeclimate)

Sets the climatology used to provide the mode radius and mode width of the aerosol log normal distribution at any point in the atmosphere. The user will always set this property. This property should be set as part of the initialization before either SetAtmosphericState(), SetLocation() or CalculateCrossSections() are called. The climatology must support