Inversion of aerosol size distribution by using genetic algorithms and multi-sensor data

In this article, we introduce the genetic algorithm into the inversion of aerosol size distribution. We are often faced with limited or insufficient observations in remote sensing and the observations are contaminated. The particle spectrum extinction equation is an ill-posed integral equation of the extinction inversion method^[1]. To overcome the ill-posed nature, we use a double logarithmic normal distribution function to express the aerosol size distribution. To obtain the optimal solution, we introduce the genetic algorithm to gain the minimum sum of squared errors. Our method can improve accuracy and reduce the computational difficulty. The assumption of parameters in the bimodal distribution function is important to the inversion results. The aerosol size distribution obtained from the GRIMM 180 PM monitor and the TSI Scanning mobility particle sizers is compared with that computed via the method proposed by Dubovik and King(2000)^[2]. Obvious difference has been discovered between aerosol size distribution on the ground and in the total atmospheric column. As a result, it is necessary to develop multi-wavelength and multi-function lidar to get observe the three-dimensional distribution characteristics of aerosol.