Aerosol Optical and Micro-Physical Characteristic Derived from AERONET in Kenya*

Abstract

The identification and classicization of both natural and anthropogenic atmospheric aerosols originating from different region is becoming very useful when dealing with effect of air quality. Different areas may encounter the problem of dust storm events which is harmfully to the environment and human health. This thesis works focused mainly on the evaluation of level 1.5 data from Sunphotometer remote sensing to understand the micro-physical aerosol optical features which includes the time series analysis, aerosol properties, absorption and its classification for the hot dry season (December-February), intermediate to heavier rainy season (March-May), the cooler dry season (June-August) and short rains season (September-November). The annual mean aerosol optical depth (AOD) and extinction Ångström exponent (EAE) were 0.27 ± 0.17 and 1.01 ± 0.33 respectively. It was observed that mixed aerosols type was more dominance followed by the biomass burning (BB) and urban-industrial (UI) aerosols. During hot dry season, the mean values of AOD were observed to be higher than those recorded during rainy period. The volume size distribution graphs clearly indicate a bimodal whereby fine mode was more prevailing in hot dry season whereas coarse mode dominated in rainy season. Subject Areas Atmospheric Sciences *A huge diversity of aerosol types, size, composition & its heterogeneous distribution in temporal and spatial embody a great challenge in identifying the dominant aerosol type. Ground-based sensors such as AERONET stations are used to infer microphysical properties of aerosols based on measurements of their optical properties.

Aerosol Characterization with Long-Term AERONET Sun-Photometer Measurements in the Naples Mediterranean Area

“…Further insights on the aerosol typology can be gained by resorting to the scatter plot of α 440/870 vs. AOD 440 [22,24]. The methodology that uses the combination of these two parameters to gain information on dominant aerosol type has already been used in many previous studies [21,33,[55][56][57][58]. It is a useful method that can discriminate different classes of aerosols.…”