Studies of Atmospheric Aerosol’s Parameters during Pre-Diwali to Post–Diwali festival period over Indian Semi Arid Station i.e., Udaipur

B M Vyas,Vimal Saraswat

doi:10.5539/apr.v4n2p40

Abstract

The paper describes day to day changes observed in atmospheric aerosol’s parameters namely AI300, AOD550, , TWC,  and MC from their background reference day value over Udaipur during Pre to Post-Diwali period from 2002 to 2007. Before Diwali to Diwali, daily variations in such aerosol’s parameters values show the substantial increase order of 30- 60% from their respective background. Afterward Diwali, such change in AI300 shows the decreasing behavior, in sharp contrast to this, daily variations in AOD550,  and MC exhibit either lower value or attain the same peak value depending upon the corresponding level of TWC and rainfall activity of that particular year. These variations are not instantly but with certain delay in the same period. A considerable amount of implication in aerosols loading is observed in terms of reduction in SHWRF from 20-30% during the enhancement period of aerosol’s parameters. However, DSWRF does not show any appreciable change. The main possible causes of increase in aerosol's loadings within above period are discussed in views of inter mixed effect of local emission activity and long range transport of aerosols from heavy polluted IGP site and in reduction of PBL height and wind speed.

Highlights

The paper describes day to day changes observed in atmospheric aerosol’s parameters namely AI300, AOD550, Total Water Vapour Column Content (TWC), and Mass Concentration (MC) from their background reference day value over Udaipur during Pre to Post-Diwali period from 2002 to 2007
From the close look to nature in variation of AI300 and AOD550 along with TWC, the value of both AI300 and AOD550 parameters increase with the increase in TWC during the preceding Diwali days with certain delay
The following main facts are summarized below: 1) During Pre-Diwali period, significant changes in peak value of 20% to 50% in several aerosols loading parameters like AOD550, MC, β and AI300 are observed from Pre-Diwali to Diwali days depending on the extent of nature of variation in TWC and position of the source region of air mass backward wind trajectories in that particular year

Summary

Introducation

Atmospheric aerosols are microscopic solid and liquid particles of several chemical species suspended in the Earth’s atmosphere (Albrecht, 1989; Charlson et al, 1992). The effects of firework activities on short term perturbation in air pollutant levels and its chemical compositions were carried out by several researchers during past years of Indian festival Diwali, New-Year and other celebrations over India and other parts of the globe (Attri et al, 2001; Ravindra et al, 2003; Barman et al, 2008; Thakur et al, 2010) Their main findings suggested that in such occasions, exceptionally high emission levels of several air pollutants (i.e., different trace toxic metals present in various sizes of Suspended Particulate Matters), air toxic gases and chemical matters were observed above the prescribed limit of their National Ambient Air Quality Standard levels. The data sets of PBL, Wind-Speed, Sensible Heat Radiation Flux Density (SHRFD, W/m2), Downward Short Waves Radiation Fluxes Density (DSWRFD, W/m2) are taken from the NCEP/NCAR and re-analysis by using a NOAA website for a period from 2005 to 2009 (References there in)

Data Analysis

Results and Discussions

Conclusions