Spectral Aerosol Transmittance in the Ultraviolet and Visible Spectra in Athens, Greece

Abstract

This work investigates the spectral atmospheric transmittance due to aerosols in the urban environment of Athens during a period of one year. The spectral transmittance due to aerosols is derived using measurements of spectral direct-beam solar irradiance in the 310-575 nm spectral band. This derivation is accomplished by using a radiative transfer model for estimating the partial spectral atmospheric transmittance functions due to Rayleigh scattering, and absorption by ozone, nitrogen dioxide and water vapor. The seasonal and diurnal variation of the aerosol transmittance is investigated and the results are discussed with a view to air pollution sources, meteorological factors and topographic characteristics of the Athens basin.

Comparison between experimental data and modeling estimates of aerosol optical depth over Athens, Greece

“…The calibration of the instrument in the intermediate time interval was achieved by a linear interpolation of the recorded values between the two calibrations assuming a linear degradation of the PPS sensitivity with time. A number of applications using PPS together with a detailed description of PPS have appeared in the literature involving the estimation of the spectral partial and total atmospheric attenuation properties, the total O 3 and NO 2 columns, the atmospheric turbidity and aerosol studies (Adamopoulos et al, 2000Kambezidis et al, 1997aKambezidis et al, , b, 2000aKambezidis et al, , b, 2001Kambezidis et al, , 2005. The atmospheric conditions in the period of measurements exhibited significantly spatial and temporal variability due to the complex topography of the Athens basin (Adamopoulos et al, 2000).…”

“…Many studies with these turbidity factors have already been published for the Athens' atmosphere (e.g. Kambezidis et al, 1997aKambezidis et al, , b, 2001Kambezidis et al, , 2005.…”

On the characterization of aerosols using the Ångström exponent in the Athens area

“…These solar spectra lie in the range 300-1000 nm. Previous works (Adamopoulos et al, 2005;Kambezidis et al, 2000aKambezidis et al, , 2000bKambezidis et al, , 2001Kambezidis et al, , 2005 used the UV and VIS spectral range (310-575 nm) in their analysis, while Kambezidis et al (1997a, b) utilized the spectral region 310-830 nm. The wavelength of 870 nm is used for the first time.…”

“…More technical details of PPS are given in Kaskaoutis et al (2006b). A number of applications using PPS have appeared in the literature involving the estimation of the spectral partial and total atmospheric attenuation properties, the total O 3 and NO 2 columns, the atmospheric turbidity and aerosol studies (Adamopoulos et al, 2000(Adamopoulos et al, , 2005Kambezidis et al, 1997aKambezidis et al, , b, 2000aKambezidis et al, , b, 2001Kambezidis et al, , 2005.…”

Dependence of the spectral diffuse-direct irradiance ratio on aerosol spectral distribution and single scattering albedo

“…The scattering by air molecules and aerosols attenuates the solar radiation over its whole spectrum, while the absorption modifies it in selective spectral bands due to the action of various atmospheric constituents, mainly including ozone, water vapor, oxygen, carbon dioxide, and nitrogen dioxide (Leckner, 1978;Jacovides et al, 2005;Kanniah et al, 2010). The presence of aerosols in the atmosphere has a significant impact on both the overall transmission of solar radiation (dominated by scattering) and the global atmospheric heating process (dominated by absorption) (Kambezidis et al, 2005;Kim and Ramanathan, 2008;Antón et al, 2012). However, due to the unavailability of a dense network of spectral radiation measurements over the globe, various radiative transfer models have been developed to simulate the complex interactions between aerosols, clouds, and radiation (Bird and Riordan, 1986;Gueymard et al, 1993Gueymard et al, , 2005.…”