Atmospheric Pollution Research 6 (2015) 511‐520 © Author(s) 2015. This work is distributed under the Creative Commons Attribution 3.0 License. A Atm spheric P Pollution R Research www.atmospolres.com Celebration-induced air quality over a tropical urban station, Pune, India Panuganti C. S. Devara 1 , Katta Vijayakumar 2 , Pramod D. Safai 2 , Made P. Raju 2 , Pasumarti S. P. Rao 2 1 Amity Centre for Ocean‐Atmospheric Science and Technology (ACOAST), Amity University Haryana, Gurgaon (Manesar) 122 413, India 2 Indian Institute of Tropical Meteorology, Dr. Homi Bhabha Road, Pune 411 008, India ABSTRACT In this paper, we studied the regional aerosol and air quality over an urban location, Pune, India during the period from 8 to 18 November 2012, encompassing a major Indian celebration, namely, Diwali Festival (12–14 November 2012) and also a clean (control) day (9 November 2012). A suit of ground–based measurements, employing solar radiometers (Microtops II and Cimel Sun–sky radiometer), Nephelometer, and satellite observations carried out over the study region have been applied for these investigations. The study revealed many interesting results which include (i) almost four–fold enhancement in AOD and fine mode dominated aerosol size distribution (ASD) during Diwali compared to clean day conditions; (ii) higher columnar water vapor (H2O), nitrogen dioxide (NO2), and lower ozone (O3) during Diwali period; (iii) higher cooling at bottom (–117 W m –2 ) and top of the atmosphere (–33 W m –2 ) and warming (+82 W m –2 ) in the atmosphere during the festival period, (iv) abundance of fine mode anthropogenic scattering particles associated with greater real part and smaller imaginary part of refractive index, and higher single scattering albedo, (v) higher backscattering coefficient revealing intrusion of more aerosol particles, higher depolarization ratio indicating particles of non–spherical nature, presence of water–phase particles, more polluted smoke and dust particles, (vi) greater attenuation and poor horizontal/vertical visibility, and (vii) dominance of urban industrial/biomass burning aerosols among other aerosol types. These results have been compared with concurrent satellite products and found to be consistent. The results have been further explained with local meteorology, back–trajectory analysis and satellite rapid response images. Keywords: Aerosols and gases, air quality, celebrations, radiative forcing, visibility Corresponding Author: Panuganti C. S. Devara  : +91‐124‐2337637  : +91‐124‐2337016  : pcsdevara@ggn.amity.edu Article History: Received: 25 July 2014 Revised: 10 December 2014 Accepted: 11 December 2014 doi: 10.5094/APR.2015.057 1. Introduction Fireworks are an integral part of celebrations ranging from smaller scale local events such as birthdays or weddings, up to nationwide celebrations, often commemorating specific historical events, all over the world. Generally, two kinds of fireworks are used; one which can be exploded on ground, and the other one in the air. Nevertheless, the fine particulate matter generated by outdoor pyrotechnic display affects regional air quality, health, weather and climate. A variety of pyrotechnics employed in these works produce various visual, light, sound, gas and smoke effects. Such activities on diverse occasions in every country perturb the earth–atmosphere radiation balance due to additional anthro‐ pogenic activities in different ways. These celebrations can cause acute short–term air quality degradation (e.g., Drewnick et al., 2006) and long–term negative effects to human health (Bach et al., 1975; Vijayakumar and Devara, 2012a; Simha et al., 2013). Burning of fireworks release gaseous pollutants such as ozone, sulfur dioxide, nitrogen oxides (Attri et al., 2001; Ravindra et al., 2003) and suspended particulates with trace metals and organic compounds (Babu and Moorthy, 2001; Steinhauser et al., 2008; Vecchi et al., 2008; Barman et al., 2009; Thakur et al., 2010; Betha and Balasubramanian, 2013; Chatterjee et al., 2013) and reduction in visibility (Clark, 1997). The impacts of fireworks on aerosol size distribution (PM10) and associated barium (Ba), which has direct bearing on human health (muscle cramps, heartbeat, asthma etc.), particle radiative and toxicological effects have been reported by Khaparde et al. (2012). Their results indicate that the Ba mass–size distribution depends on the intensity of the fireworks and distance between the burning of firecrackers from the monitoring site and hence suggest minimizing human exposure through public aware‐ ness programs. The results, so far, available in the literature were mostly obtained from either point monitors or direct measuring equipment (samplers). Measurement of fireworks aerosols and precursor gases with high time resolution, using satellite and ground–based passive and/or active remote sensing techniques are very sparse. In this paper, we describe the simultaneous measurements of columnar aerosol optical, microphysical, radiative properties, ozone, nitrogen dioxide, water vapor from several ground–based, satellite remote sensing and in–situ techniques, and discuss the results with the help of local surface– level meteorological parameters, multi–level HYbrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) back–trajectory air mass analysis and satellite images. 2. About the Celebration Diwali is one of the most fabulous festivals celebrated in India with joy and happiness. It is also known as “Festival of Lights”, and is one of the popular cultural and religious festival during which millions of people light traditional lamps and ignite fireworks. Hand–held, ground–based, and airborne fireworks are performed during this occasion. It is usually celebrated in the month of October/November in every year. Diwali Festival is normally cele‐ brated over a span of 5 days. The festive fever starts a few days prior to Diwali with people igniting fireworks, shopping for the celebrations and visiting each other and reaches a crescendo on the day of Diwali. A huge amount of crackers and sparklers are burnt mainly on the day of festival (Diwali day) and also on the day