Potential Source Regions Contributing to Seasonal Variations of Black Carbon Aerosols over Anantapur in Southeast India

Abstract

Continuous measurements of black carbon (BC) mass concentration performed at Anantapur [14. 62°N, 77.65°E, 331 m asl], a suburban location in southeast India, using an Aethalometer from January to December, 2010, are analyzed and discussed here. The annual mean BC mass concentration ([BC]) was 3.03 ± 0.27 µg/m 3 for the above study period. The sharp morning (fumigation) peak occurs between 07:00 and 08:00 h almost an hour after the local sunrise while a broad evening (nocturnal) peak is at ~21:00 h with a minimum in noon hours (14:00-16:00 h). The seasonal mean values of [BC] are 5.05 ± 0.51 μg/m 3 in the winter, 3.77 ± 1.23, 1.55 ± 0.51, and 2.33 ± 0.82 µg/m 3 in the summer, monsoon and postmonsoon seasons, respectively. High BC values tend to occur when the wind is directed from the 180-225° sector, which may be well defined by the geographical location of the observation site. During the winter, the trajectory air mass pathways originated through north or central India with significant advection of continental aerosols arriving before the measurement region, results in an enhanced [BC]. Whereas in the monsoon season, the pristine marine air mass from the oceanic environment led to decrease in the concentration of BC. Comparison of monthly mean variations in AOD at 500 nm and black carbon aerosols is observed to be positive with poor correlation coefficient of 0.42. The ratio of BC/PM 2.5 varied from 1.3% to 7.2% with a mean value of 4.6% at Anantapur during the observation period and this ratio decreased with decreasing Ångström exponent (alpha).

Intra-seasonal variability of black carbon aerosols over a coal field area at Dhanbad, India

“…It is obvious as all the possible anthropogenic sources emitting BC are more pronounced over IGP region as well as urban atmospheres in cities with much higher industrial activities and vehicular emissions. At Darjeeling (Sarkar et al, 2014), Chandigarh (Chowdhury et al, 2007), Anantapur (Reddy et al, 2012), Bangalore (Aswathy et al, 2010), Pune (Safai et al, 2014), Kullu (Kuniyal, 2010), and Dehradun (Kant and Dadhwal, 2010), the BC concentration was~35% lower than the present study. The most interesting feature was seen at popular tourist spots in India, like Kullu and Darjeeling showing much higher BC, i.e.…”

Real-Time Performance of the microAeth® AE51 and the Effects of Aerosol Loading on Its Measurement Results at a Traffic Site

“…They have been used extensively to monitor environmental BC levels because of their ease of operation, and favorable time resolution (Watson et al, 2005;Park et al, 2006;Chow et al, 2009). Such online measurement instruments are critical to research studies that seek to characterize short-term and/or long-term variability in BC levels, such as by measuring source emissions that change rapidly, comparing time-varying outdoor/indoor air pollution levels, or observing dynamic trends in ambient air quality (Badarinath and Latha, 2006;Fruin et al, 2008;Rodríguez et al, 2008;Sandradewi et al, 2008;Dutkiewicz et al, 2009;Wang et al, 2009;Snyder et al, 2010;Boogaard et al, 2011;Hyvärinen et al, 2011;Reche et al, 2011;Viana et al, 2011;Wang et al, 2011;Reddy et al, 2012;Wang et al, 2012;Cheng et al, 2013). They also could be used to evaluate the light absorption coefficient of aerosol by measuring the attenuation of light through deposited aerosol (Lavanchy et al, 1999;Weingartner et al, 2003;Arnott et al, 2005;Fialho et al, 2005;Schmid et al, 2006).…”

Seasonal Characteristics of Black Carbon Aerosol and its Potential Source Regions in Baoji, China

“…The annual arithmetic mean (± standard deviation) concentration of BC was 2.9 ± 1.7 µg m -3 .The data in Table 1 indicate that the annual average BC mass concentration in Baoji was lower relative to those of some urban areas of China such as Beijing (6.3 µg m -3 (Zhao et al, 2013)), Guangzhou (4.7 µg m -3 ), Chengdu (10.8 µg m -3 ), Xi'an (14.7 µg m -3 (Cao et al, 2009)), Nanjing (4.2 µg m -3 (Zhuang et al, 2014)), and Xianghe (4.9 µg m -3 (Ran et al, 2016)), and that it was comparable to those of Shanghai (3.3 µg m -3 (Feng et al, 2014)) and Hefei (3.5 µg m -3 ). Compared with areas outside China, the annual mean BC mass concentration in Baoji was similar to or higher than the levels reported for Toulon, France (0.6 µg m -3 (Saha and Despiau, 2009)), Granada, Spain (3.0 µg m -3 (Lyamani et al, 2011)), Anantapur, India (3.0 µg m -3 (Reddy et al, 2012)), and Mexico City (0.9-3.1 µg m -3 (Retama et al, 2015)), but lower than those of Delhi, India (6.7 µg m -3 , (Tiwari et al, 2013)) and Kathmandu, Nepal (11.6 µg m -3 , (Putero et al, 2015)). The differences in the BC mass concentrations can be attributed to the distinct emission sources and meteorological conditions as well as the different methods and times of year applied for BC measurement.…”

“…Diurnal variations of BC can effectively reflect the role of local anthropogenic activities and mesoscale atmospheric processes (Reddy et al, 2012). Fig.…”