Study of aerosol humidification impact on visibility in airports

The low visibility leads to many problems in such spheres of human activity as air transport and functioning of airports. Increase of aerosol particles in atmosphere causes the increase of extinction coefficient and low visibility. To estimate the hygroscopicity of aerosol, the coefficient of hygroscopic increase which depends on diameter of aerosol particles and the relative humidity is used. The general parameter of multimode aerosol hygroscopicity is suggested which is determined as averaged weighted value of concentrations of all modes of aerosol particles. The parameters of hygroscopicity are used as the weight coefficients. The research task is formulated as follows. Upon the constancy of some functional parameters the dependence of hygroscopicity parameters on particle diameter should be found. The physical meaning of the considered optimization task is that the worst dependence of hygroscopicity parameter on particles diameter should be calculated, upon which the minimum amount of water worsening the visibility would be needed. The authors suggest the condition which can cause maximum possible worsening of visibility due to aerosol humidification.