1Head and Associate Professor (Principal Investigator of Project), Centre for Environmental Sciences, Central University of Jharkhand, Brambe, Ranchi-835 205, Jharkhand, India
2Project Fellow, Birla Institute of Technology, Mesra, Ranchi
*Corresponding author Email id: manoj.kumar@cuj.ac.in
Online published on 24 November, 2014.
Spectral aerosol optical depth (AOD) measurements, estimated from a hand-held, microprocessorbased sun photometers [MICROTOPS-II (version 2.43)] over Ranchi, India were analyzed from March 2012 to February 2013 (a total of 190 days of clear-sky observations). The results showed seasonal variation with high values in summer and low values in winter. The summer increase is found to be due to the high wind speed producing larger amounts of wind-driven dust particles. The winter AOD values decrease more at higher wavelengths, indicating a general reduction in the number of bigger particles. The amplitude of the observed high AOD values in summer is higher (low during winter) for longer wavelengths, which shows that coarse particles contribute more to the observed variation as compared to sub-micron particles. To characterize the aerosol optical depths, the Angstrom parameters α and β were used.
Aerosols, AOD, Sunphotometer, Back trajectory, Aethalometer, BC
