International E-publication: Publish Projects, Dissertation, Theses, Books, Souvenir, Conference Proceeding with ISBN.  International E-Bulletin: Information/News regarding: Academics and Research

Diurnal and Monthly Variation of Aerosol Optical Depth and Angstrom’s Parameters in Kathmandu Valley, Nepal

    , , , ,

Author Affiliations

  • 1Institute of Engineering, Thapathali Campus, Tribhuvan University, Kathmandu, Nepal
  • 2Institute of Engineering, Tribhuvan University, Lalitpur, Nepal
  • 3Central Department of Physics, Tribhuvan University, Kathmandu, Nepal
  • 4Institute of Engineering, Tribhuvan University, Lalitpur, Nepal
  • 5Institute of Engineering, Tribhuvan University, Lalitpur, Nepal

Res.J.chem.sci., Volume 6, Issue (2), Pages 40-44, February,18 (2016)

Abstract

Aerosol optical depth (AOD) is measured at five optical channels by Microtops II Sunphotometer at Institute of Engineering, Pulchowk, Lalitpur, Nepal from November 2011 to March 2013 in clear non cloudy days. The Angstrom’s turbidity parameters, α and β, have been calculated from AOD measurements and their variation have been analyzed on daily and monthly basis. The result shows that value of α and β varies throughout the day because of the change in meteorological parameters. It is observed that during the measurement period, the monthly average minimum and maximum values of a are 0.24 and 1.27 in September 2011 and December 2012 respectively. Likewise the value of β is 0.16 in December 2012 and 0.43 in April 2012. The variation between the parameters a and β is observed in anti-correlation throughout the day during all months indicating continuous distribution of the fine and coarse particles.

References

  1. Putero D., Cristofanelli P., Marinoni A., Adhikari B.,Shrestha S.D., Verza G.P., Landi T.C., Calzolari F.,Busetto M., Agrillo G., Biancofiore F., DiCarlo P.,Panday A.K., Rupakheti M. and Bonasoni P. (2015), Seasonal variation of ozone and black carbon observed atPaknajol, an urban site in Kathmandu Valley, Nepal.Atmospheric Chemistry and Physics, 15, 13957-13971.
  2. UNEP and WMO (2011), Integrated Assessment ofBlack Carbon and Tropospheric Ozone, UNEP, Nairobi.
  3. Gobbi G.P., Angelini F., Bonasoni P., Verza G.P.,Marinoni A. and Barnaba F. (2010), Sunphotometery ofthe 2006-2007 Aerosol Optical/radiative Properties at theHimalayan Nepal Climate Observatory-Pyramid (5079 ma.s.l.), Atmospheric Chemistry and Physics, 10: 11209-11221.
  4. Salby M.L. (1996), Fundamentals of AtmosphericPhysics, Academic Press, USA, 258-264. ISBN-13: 978-0-12-615160-2.
  5. Ganesh K.E., Umesh T.K. and Narasimhamurthy B.(2011), Atmospheric Turbidity over a continental stationMysore, India. Indian Journal of Radio and SpacePhysics. 40, 85-94.
  6. Bhattarai B.K. (2007), Factors Affecting SolarUltraviolet Radiation based on Some Case: Studies inNorway and Nepal, Doctoral Thesis at NTNU. 2007:61Trondheim Norwegian University of Science andTechnology, Trondheim, Norway, ISBN978-82-471-1335-6.
  7. Angstrom A.K. (1961), Techniques of Determining theTurbidity of the Atmosphere, Tellus XIII: 214.
  8. Pandey A. and Prinn R.G. (2009), Duirnal cycle of airpollution in the Kathmandu Valley, Nepal: Observations. J.Geophys. Res. 114, D09305, doi:10.1029/2008JD009777,209.
  9. Sapkota B.K. (2002), Suspended Matter in the Urban Airof Kathmandu Valley, Better Air Quality in Asia andPacific Rim Cities (BAQ 2002), Hong Kong SAR, PS-24-1-PS-24-6.
  10. Shrestha P., Barros A.P. and Khlystov A. (2010), Chemical composition and aerosol size distribution of themiddle mountain range in the Hhimalayas during the2009 pre-monsoon season, Atmospheric Chemistry andPhysics, 10, 11605-11621.
  11. Shrestha R.M. and Rajbhandari S. (2010), Energy andenvironmental implications of carbon emission reductiontargets: Case of Kathmandu Valley, Nepal. Energ, Policy, 38, 4818-4827.
  12. Sharma R.K., Bhattarai B.K., Sapkota B.K., Gewali M.B.and Kjeldstad B. (2012), Black Carbon Aerosol Variationin Kathmandu Valley, Nepal. Atmos. Environ. 63, 282-288.
  13. User’s Guide: Microtops II Ozone Monitor andSunphotometer (version 2.43) (2001). Solar LightCompany, Inc.721 Oak Lane, PA 19126, Philadelpjiya,USA.
  14. Iqbal Muhammad (1983), An Introduction to SolarRadiation, Academic Press, Canada, pp 107-154. ISBN:0-12-373752-4 (pbk).
  15. Angstrom A.K. (1930), On the AtmosphericTransmission of Sun Radiation, II. Geogr. Ann. H 2 and3.
  16. Department of Hydrology and Meteorology (2013), Government of Nepal. Data Section, Meteorological Dataof Year 2011, 2012 and 2013.
  17. Mukherjee I. and Chakraborty N. (2012), Study oncorrelation of Angstrom Turbidity Coefficient (a) withAerosol Optical Depth (t) over a period of Two Years(2004-2006) for the Special Mangrove Ecosystem ofSundarbans, Journal of Air Pollution.1, 74-81.
  18. Rana S., Kant Y. and Dadhwal V.K. (2009), Diurnal andSeasonal Variation of Spectral Properties of Aerosolsover Dehradun, India. Aerosol and Air Quality Research,9(1), 32-49.
  19. Poudyal K.N., Bhattarai B.K., Sapkota B.K. andKjeldstad B. (2012), Estimation of Global SolarRadiation using Sunshine Duration in Himalayan Region, Res. J. Chem. Sci., 2(11), 20-25.
  20. Ranjan R.R., Joshi H.P. and Iyer K.N. (2007), SpectralVariation of Total Column Aerosol Optical Depth overRajkot: A Tropical Semi-arid Indian Station, Aerosol andAir Quality Research. 7(1), 33-45.