A study of atmospheric aerosol optical properties over Alexandria city- Egypt

23rd International Conference on Spectral Line Shapes

Kohil, E.E.^1 ; Saleh, I.H.^1 ; Ghatass, Z.F.^1

Department of Environmental Studies, Institute of Graduate Studies and Research, Alexandria University, 163 Horrya Avenue, P.O. 832 Shatby, Alexandria, Egypt^1

关键词: Aerosol optical depths;    Aerosol optical property;    Atmospheric loading;    Optical radiations;    Precipitable water;    Seasonal variation;    Solar intensities;    Water vapor contents;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/810/1/012033/pdf
DOI  :  10.1088/1742-6596/810/1/012033

来源: IOP

【 摘 要 】

Aerosols are minute particles suspended in the atmosphere. When these particles are sufficiently large, we notice their presence as they scatter and absorb sunlight. They scatter and absorb optical radiation depending upon their size distribution, refractive index and total atmospheric loading. Aerosol optical depth (AOD) was measured at Alexandria city (31° 16′ N, 30° 01′ E and 21 m above sea level) using hand-held microprocessor-based sun photometer "MICROTOPS II". AOD is studied at five different wavelengths from 380 to 1020 nm during the period from Aug-2015 to Feb-2016. Precipitable water column (PWC) is estimated from the measurements of solar intensity at 936 and 1020 nm. Diurnal, monthly and seasonal variation of AOD and water vapor content was studied during the study period. The seasonal variation of AOD has high value (0.416) in summer and low value (0.176) in winter at wavelength of 380 nm. The changes in the PWC have been found to be correlated with changes in AOD. This is supported by the observed increase of AOD with relative humidity (RH) values.