Aerosol Properties over Ranchi Measured from Aethalometer
ABSTRACT
Continuous and near-real-time measurements of the mass concentration of Aerosol Black Carbon (BC) were carried out 1st to 31st July 2010 of rainy season and compare with data of July-2010 to March-2011 using an Aethalometer (model AE-31 of Magee Scientific, USA). The principle of the Aethalometer is to measure the attenuation of a beam of light transmitted through a filter, while the filter is continuously collecting an aero-sol sample. This measurement is made at successive regular intervals of a time base period has been. the BC mass concentration is estimated by measuring the change in the transmittance of a quartz filter tape, on to which the particles impinge. The instrument was operated at a time base of 5 min, round the clock with a flow rate of 4-liter min–¹, to study the impact of rainy season on black carbon concentrations over a typical urban environment namely Ranchi, India. BC concentrations were high during morning (0600 to 0900 h) and evening hours (1900 to 2300 h) compared to afternoon hours. During early morning hours, high values of BC are attributed to the turbulence set-in by the solar heating which breaks the night-time stable layer and aero-sols in the nocturnal residual layer are mixed up with those near the surface.
Continuous and near-real-time measurements of the mass concentration of Aerosol Black Carbon (BC) were carried out 1st to 31st July 2010 of rainy season and compare with data of July-2010 to March-2011 using an Aethalometer (model AE-31 of Magee Scientific, USA). The principle of the Aethalometer is to measure the attenuation of a beam of light transmitted through a filter, while the filter is continuously collecting an aero-sol sample. This measurement is made at successive regular intervals of a time base period has been. the BC mass concentration is estimated by measuring the change in the transmittance of a quartz filter tape, on to which the particles impinge. The instrument was operated at a time base of 5 min, round the clock with a flow rate of 4-liter min–¹, to study the impact of rainy season on black carbon concentrations over a typical urban environment namely Ranchi, India. BC concentrations were high during morning (0600 to 0900 h) and evening hours (1900 to 2300 h) compared to afternoon hours. During early morning hours, high values of BC are attributed to the turbulence set-in by the solar heating which breaks the night-time stable layer and aero-sols in the nocturnal residual layer are mixed up with those near the surface.
Cite this paper
nullM. Kumar, K. Lipi, S. Sureshbabu and N. Mahanti, "Aerosol Properties over Ranchi Measured from Aethalometer," Atmospheric and Climate Sciences, Vol. 1 No. 3, 2011, pp. 91-94. doi: 10.4236/acs.2011.13010.
nullM. Kumar, K. Lipi, S. Sureshbabu and N. Mahanti, "Aerosol Properties over Ranchi Measured from Aethalometer," Atmospheric and Climate Sciences, Vol. 1 No. 3, 2011, pp. 91-94. doi: 10.4236/acs.2011.13010.
References
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[1] Angstrom, A. 1929. On the atmospheric transmission of sun radiation and on dust in the air, Geogr. Ann., 11, pp. 156-166. [2] Volz, F. E. 1959. Photometer mit Selen-Photoelement zur spektralen Messung der Sonnenstrahlung und zur Bestimmung der Wellenlaengenabhaengigkeit de Dunsttruebung, Arch. Meteorol. Geophys. Bioklin, B10, pp. 100- 131. [3] Twitty, J. T. 1975. The inversion of aureole measurements to derive aerosol size distributions, J. Atmos. Sci., 32, 584-591. [4] Kaufman, Y. J., Gitelson, A. and Karnieli, A. et al., 1994. Size distribution and scattering phase function of aerosol particles retrieved from sky brightness measurements, J. Geophys. Res., 99, pp. 10341-10345. [5] Nakajima, T., Tonna, G. and Rao, R. et al., 1996. Use of sky brightness measurements from ground for remote sensing of particlulate polydispersions, Appl. Opt., 35, pp. 2672-2686. [6] Highwood, E.J., Kinnersley, R.P., 2006.When smoke gets in our eyes: The multiple impacts of atmospheric black carbon on climate, air quality and health. Environment International, 32, 560-566. [7] Reddy, M.S., Venkataraman, C., 2000. Atmospheric optical and radiative effects of anthropogenic aerosol constituents from India. Atmos. Environ. 34, 4511-4523. [8] Babu and Moorthy, 2001. S.S. Babu and K.K. Moorthy, Anthropogenic impact on aerosol black carbon mass concentration at a tropical coastal station: a case study. Curr. Sci. 81 9 (2001), pp. 1208-1214. [9] Latha, K.M., Badrinath, K.V.S., 2005.Seasonal variation of black carbon aerosols and total aerosol mass concentrations over urban environment in India. Atmospheric Environment 39, 4129-4141.