OPEN ACCESS

Articles online

Characterisation of Absorbing Aerosols Using Ground and Satellite Data at an Urban Location, Hyderabad

Category: Urban Air Quality

Volume: 16 | Issue: 6 | Pages: 1427-1440
DOI: 10.4209/aaqr.2014.09.0220
PDF | RIS | BibTeX

Subin Jose1, Kaundala Niranjan2, Biswadip Gharai 1, Pamaraju Venkata Narasimha Rao1, Vijayakumar S. Nair3

  • 1 Atmospheric & Climate Sciences Group, ECSA, NRSC, Balanagar, Hyderabad, India
  • 2 Department of Physics, Andhra University, Andhra Pradesh, India
  • 3 Space Physics Laboratory (SPL), Vikram Sarabhai Space Centre, Trivandrum, India

Highlights

Predominant aerosol types are from fossils fuel, anthropogenic emissions.
BC showed a significant diurnal variation.
Biomass/dust aerosols in its pure form are not found.
Aerosols are confined within 2 km from the surface during winter.


Abstract

In the present study we have attempted to characterize aerosols using their optical properties over a tropical urban location of Hyderabad, India. We have analyzed three years of in-situ data on aerosol absorption from Aethalometer and scattering from Nephelometer measurements. Satellite based absorption measurements from ozone monitoring instrument, absorbing aerosol index are also analyzed to investigate the role of long range transport of dust. Further, the Cloud–Aerosol Lidar Pathfinder Satellite Observations (CALIPSO) data is used to study the vertical extent of aerosol particles as well as their sphericity using its particulate depolarization ratio. The study revealed that irrespective of seasonal variation, local anthropogenic fossil fuel aerosols form the predominant aerosol type over this site. Biomass/dust aerosols in their pure form are not present during the study period; however the spread of frequency distribution of scattering Angstrom exponent and absorption Angstrom exponent suggested their possible existence in mixed condition with local anthropogenic aerosols. The analysis of columnar aerosol absorption data during pre-monsoon period showed the dominance of UV absorbing dust aerosols in the study region. CALIPSO data analysis over study area showed that majority aerosols are confined within 2 km from the surface during winter while in pre-monsoon particles are distributed throughout the profile (~6 km) with extinction coefficient varying between 0.1–0.2 km–1. As the season shift from winter to pre-monsoon a change in sphericity of particle is observed. Cluster mean trajectory analysis revealed that during pre-monsoon majority of air mass movements (~68%) are from western side passing through dust source region like Persian Gulf and Thar Desert before entering into Indian region. During post-monsoon (~70%) and winter (~65%), majority of the air masses are coming from north-west and north-east side of the study area where biomass burning is quite frequent during this period.

Keywords

Absorption coefficient Angstrom exponent Black carbon Aerosol index and particulate depolarization ratio


Related Article

Optical Properties, Chemical Composition and the Toxicological Potential of Urban Particulate Matter

Máté Pintér, Noémi Utry, Tibor Ajtai , Gergely Kiss-Albert, Beatrix Jancsek-Turóczi, Kornélia Imre, Andrea Palágyi, László Manczinger, Csaba Vágvölgyi, Eszter Horváth, Nóra Kováts, András Gelencsér, Gábor Szabó, Zoltán Bozóki
Article In Press
DOI: 10.4209/aaqr.2016.09.0395
PDF