Abstract
Aerosol optical depth and Angstrom coefficients for three sites in Bangkok and suburbs are examined: Silpakorn University at Nakhon Pathom, NP (13.82°N, 100.04°E), the Asian Institute of Technology at Phatum Thani, AIT (14.08°N, 100.62°E) and the Thai Meteorological Department at Bangkok, BK (13.73°N, 100.57°E). Sunphotometers have been used to measure direct normal spectral irradiance at these sites for a period of 2 years (2004–2005). Cloudless conditions were selected and Bouguer’s law was employed to obtain aerosol optical depth. All three sites exhibit strong seasonal variations, with the highest values occurring at the height of the dry season in April, and the lowest occurring during the rainy season in July. April turbidity conditions are very high, as evidenced by maximum 500 nm optical depths of between 1.4 to 2.0 that were measured at all three locations. The Angstrom exponent α also showed a marked seasonal change, with highest values at the height of the dry season.
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Abbreviations
- \({\text{I}}_{{\text{o $ \lambda $ }}} $% MathType!End!2!1!\) :
-
Extraterrestrial solar irradiance
- I a :
-
Modelled direct irradiance at the surface with aerosols
- I 0 :
-
Modelled direct irradiance at the surface without aerosols
- D a :
-
Modelled diffuse irradianxce at the surface with aerosols
- D 0 :
-
Modelled diffuse irradiance at the surface without aerosols
- G a :
-
Modelled global irradiance at the surface with aerosols
- G 0 :
-
Modelled global irradiance at the surface without aerosols
- G m :
-
Measured global irradiance at the surface
- R :
-
Correlation coefficient
- SD:
-
Standard deviation
- m r :
-
Relative air mass
- \(\tau _{\text{ $ \lambda $ }}^\prime \) :
-
Total atmospheric optical depth
- \(\tau _{{\text{a $ \lambda $ }}}^\prime \) :
-
Optical depth due to aerosol scattering and absorption
- \(\tau _{{\text{g $ \lambda $ }}}^\prime \) :
-
Optical depth due to the atmospheric gases absorption
- \(\tau _{o{\text{ $ \lambda $ }}}^\prime \) :
-
Optical depth due to the ozone absorption
- \(\tau _{{\text{r $ \lambda $ }}}^\prime \) :
-
Optical depth due to Rayleigh scattering
- \(\tau _{{\text{w $ \lambda $ }}}^\prime \) :
-
Optical depth due to the water vapour absorption
- α:
-
Wavelength exponent
- β:
-
Angstrom’s turbidity coefficient
- λ:
-
Wavelength
References
Angstrom A (1929) On the atmospheric transmission of sun radiation and dust in the air. Geograph Annal 2:156–166
Angstrom A (1964) The parameters of atmospheric turbidity. Tellus 16:64–75
Holben BN, Setzer A, Eck TF, Pereira A, Slutsker L (1996) Effects of dry season biomass burning on Amazon basin aerosol concentrations and optical properties. J Geophys Res 110(D144):19465–19481
Iqbal M (1983) An introduction to solar radiation. Academic, New York
Kaufman YJ, Gitelson A, Karnieli A, Ganor E, Fraser RS, Nakajima T, Mattoo S, Holben BN (1994) Size distribution and phase function of aerosol particles retrieved from sky brightness measurements. J Geophys Res 99(10):10341–10356
Key J, Schweiger AJ (1998) Tools for atmospheric radiative transfer: streamer and fluxnet. Comput Geosci 24(5):443–451
Maduekwe AAL, Chendo MAC (1997) Atmospheric turbidity and diffuse irradiance in Lagos, Nigeria. Sol Energy 61:241–249
Masmoudi M, Chaabane M, Medhioub K, Elleuch F (2003) Variability of aerosol optical thickness and atmospheric turbidity in Tunisia. Atmos Res 66:175–188
NEPC (National Environment Protection Council) (1997) Draft National Environment Protection measure and impact for air quality, National Environmental Protection Council Report, NEPC, Adelaide, Australia
Oke TR (1987) Boundary layer climates. Methuen, New York
Ramachandran S, Jayaraman A (2003) Spectral aerosol optical depths over bay of Bengal and Chennai: I- measurements. Atmos Environ 37:1941–1949
Tadros MTY, El-Metwally M, Hamed AB (2002) Determination of Angstrom coefficients from spectral aerosol optical depth at two sites in Egypt. Renew Energy 27:621–645
Valiente JA (1996) A study and parameterization of oceanic aerosol interaction by interpreting spectral solar radiation measurement at Nauru during TOGA-COARE. PhD Thesis, Tasmania University, Australia
Von Hoyningen-Huene W, Schmidt T, Schienbein S, Kee CA, Tick LJ (1999) Climate-relevant aerosol parameters of South-East Asian forest fire haze. Atmos Env 33:3183–3190
Xin J, Wang S, Wang Y, Yuan J, Zhang W, Sun Y (2005) Optical properties and size distribution of aerosols over the Tengger Desert in northern China. Atmos Environ 39:5971–5978
Zakey AS, Abdelwahab MM, Makar PA (2004) Atmospheric turbidity over Egypt. Atmos Environ 38:1579–1591
Zhang J, Mao J (1999) Remote sensing aerosol optical depth from space and ground. Proc. of the 20th Asian Conference on Remote Sensing, 22–25 November 1999, Hong Kong, China, pp 1–7
Acknowledgements
The authors would like to thank the Thailand Research Fund (TRF) for the financial support to carry out this research work. The authors also would like to thank Prof. S. Chirarattananon, Dr. P. Chaiwiwatworakul and Ms. S. Sudhibrabha for providing spectral data at AIT and Bangkok.
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Janjai, S., Suntaropas, S. & Nunez, M. Investigation of aerosol optical properties in Bangkok and suburbs. Theor Appl Climatol 96, 221–233 (2009). https://doi.org/10.1007/s00704-008-0026-4
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DOI: https://doi.org/10.1007/s00704-008-0026-4