Department of Physics, Indian Institute of Science Education and Research (IISER) Bhopal, Govindpura, Bhopal, 462 023, India.
Environ Sci Pollut Res Int. 2013 Mar;20(3):1617-31. doi: 10.1007/s11356-012-1053-3. Epub 2012 Jul 10.
This study characterizes over 5 years of high time resolution (5 min), airborne black carbon (BC) concentrations (July 2003 to December 2008) measured over Ahmedabad, an urban region in western India. The data were used to obtain different time averages of BC concentrations, and these averages were then used to assess the diurnal, seasonal, and annual variability of BC over the study region. Assessment of diurnal variations revealed a strong association between BC concentrations and vehicular traffic. Peaks in BC concentration were co-incident with the morning (0730 to 0830, LST) and late evening (1930 to 2030, LST) rush hour traffic. Additionally, diurnal variability in BC concentrations during major festivals (Diwali and Dushera during the months of October/November) revealed an increase in BC concentrations due to fireworks displays. Maximum half hourly BC concentrations during the festival days were as high as 79.8 μg m(-3). However, the high concentrations rapidly decayed suggesting that local meteorology during the festive season was favorable for aerosol dispersion. A multiple linear regression (MLR) model with BC as the dependent variable and meteorological parameters as independent variables was fitted. The variability in temperature, humidity, wind speed, and wind direction accounted for about 49% of the variability in measured BC concentrations. Conditional probability function (CPF) analysis was used to identify the geographical location of local source regions contributing to the effective BC measured (at 880 nm) at the receptor site. The east north-east (ENE) direction to the receptor was identified as a major source region. National highway (NH8) and two coal-fired thermal power stations (at Gandhinagar and Sabarmati) were located in the identified direction, suggesting that local traffic and power plant emissions were likely contributors to the measured BC.
本研究描述了超过 5 年的高时间分辨率（5 分钟），在印度西部城市艾哈迈达巴德上空测量的黑碳（BC）浓度（2003 年 7 月至 2008 年 12 月）。这些数据用于获得不同时间的 BC 浓度平均值，然后使用这些平均值评估研究区域内 BC 的日变化、季节变化和年变化。日变化评估显示，BC 浓度与交通车辆之间存在很强的关联。BC 浓度峰值与早晚高峰（当地时间 0730 至 0830 和 1930 至 2030）的交通高峰同时出现。此外，在主要节日（10/11 月的排灯节和杜尔加节）期间，BC 浓度的日变化显示，由于烟花表演，BC 浓度增加。节日期间最高的半小时 BC 浓度高达 79.8μg m(-3)。然而，这些高浓度迅速衰减，表明节日期间当地的气象条件有利于气溶胶扩散。用 BC 作为因变量，气象参数作为自变量，建立了多元线性回归（MLR）模型。温度、湿度、风速和风向的变化解释了测量的 BC 浓度变化的约 49%。条件概率函数（CPF）分析用于识别导致在受体点测量的有效 BC（在 880nm 处）的本地源区的地理位置。受体的东北偏东（ENE）方向被确定为主要源区。国家高速公路（NH8）和两个燃煤火力发电站（位于甘地讷格尔和萨巴尔马蒂）位于所确定的方向，表明当地交通和电厂排放可能是测量的 BC 的来源。
