Aerosol optical properties at rural background area in Western Saudi Arabia
| Autor: | Tareq Hussein, A. S. Abdelmaksoud, Mansour A. Alghamdi, Antti-Pekka Hyvärinen, Ibrahim I. Shabbaj, Kimmo Neitola, Mamdouh I. Khoder, F. M. Almehmadi, H. Al-Jeelani, H. Lihavainen |
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| Přispěvatelé: | Department of Physics |
| Rok vydání: | 2017 |
| Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences 010501 environmental sciences Noon Atmospheric sciences 114 Physical sciences 01 natural sciences ORGANIC-CARBON Diurnal cycle Sea breeze AMBIENT AEROSOL PARTICLES BROWN Absorption (electromagnetic radiation) POSITIVE MATRIX FACTORIZATION 0105 earth and related environmental sciences Scattering Single-scattering albedo Diurnal temperature variation LIGHT-ABSORPTION DESERT DUST Aerosol SOOT SOURCE APPORTIONMENT Climatology BLACK CARBON Environmental science |
| Zdroj: | Atmospheric Research. 197:370-378 |
| ISSN: | 0169-8095 |
| Popis: | To derive the comprehensive aerosol in situ characteristics at a rural background area in Saudi Arabia, an aerosol measurements station was established to Hada Al Sham, 60 km east from the Red Sea and the city of Jeddah. The present sturdy describes the observational data from February 2013 to February 2015 of scattering and absorption coefficients, Angstrom exponents and single scattering albedo over the measurement period. The average scattering and absorption coefficients at wavelength 525 nm were 109 ± 71 Mm − 1 (mean ± SD, at STP conditions) and 15 ± 17 Mm − 1 (at STP conditions), respectively. As expected, the scattering coefficient was dominated by large desert dust particles with low Angstrom scattering exponent, 0.49 ± 0.62. Especially from February to June the Angstrom scattering exponent was clearly lower (0.23) and scattering coefficients higher (124 Mm − 1 ) than total averages because of the dust outbreak season. Aerosol optical properties had clear diurnal cycle. The lowest scattering and absorption coefficients and aerosol optical depths were observed around noon. The observed diurnal variation is caused by wind direction and speed, during night time very calm easterly winds are dominating whereas during daytime the stronger westerly winds are dominating (sea breeze). Positive Matrix Factorization mathematical tool was applied to the scattering and absorption coefficients and PM 2.5 and coarse mode (PM 10 –PM 2.5 ) mass concentrations to identify source characteristics. Three different factors with clearly different properties were found; anthropogenic, BC source and desert dust. Mass absorption efficiencies for BC source and desert dust factors were, 6.0 m 2 g − 1 and 0.4 m 2 g − 1 , respectively, and mass scattering efficiencies for anthropogenic (sulphate) and desert dust, 2.5 m 2 g − 1 and 0.8 m 2 g − 1 , respectively. |
| Databáze: | OpenAIRE |
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