Tiwari S, Pipal A S, Hopke Philip K, Bisht D S, Srivastava A K, Tiwari Shani, Saxena P N, Khan A H, Pervez S
Indian Institute of Tropical Meteorology, New Delhi, India, 110060.
Environ Sci Pollut Res Int. 2015 Jul;22(14):10744-57. doi: 10.1007/s11356-015-4272-6. Epub 2015 Mar 11.
Because of high emissions of anthropogenic as well as natural particles over the Indo-Gangetic Plains (IGP), it is important to study the characteristics of fine (PM2.5) and inhalable particles (PM10), including their morphology, physical and chemical characteristics, etc., in Delhi during winter 2013. The mean mass concentrations of fine (PM2.5) and inhalable (PM10) (continuous) was 117.6 ± 79.1 and 191.0 ± 127.6 μg m(-3), respectively, whereas the coarse mode (PM10-2.5) particle PM mass was 73.38 ± 28.5 μg m(-3). During the same period, offline gravimetric monitoring of PM2.5 was conducted for morphological analysis, and its concentration was 37 % higher compared to the continuous measurement. Carbonaceous PM such as organic carbon (OC) and elemental carbon (EC) were analyzed on the collected filters, and their mean concentration was respectively 33.8 and 4.0 μg m(-3) during the daytime, while at night it was 41.2 and 10.1 μg m(-3), respectively. The average OC/EC ratio was 8.97 and 3.96 during the day and night, respectively, indicating the formation of secondary organic aerosols during daytime. Effective carbon ratio was studied to see the effect of aerosols on climate, and its mean value was 0.52 and 1.79 during night and day, indicating the dominance of absorbing and scattering types of aerosols respectively into the atmosphere over the study region. Elemental analysis of individual particles indicates that Si is the most abundant element (37-90 %), followed by O (oxide) and Al. Circularity and aspect ratio was studied, which indicates that particles are not perfectly spherical and not elongated in any direction. Trajectory analysis indicated that in the months of February and March, air masses appear to be transported from the Middle Eastern part along with neighboring countries and over Thar Desert region, while in January it was from the northeast direction which resulted in high concentrations of fine particles.
由于印度 - 恒河平原（IGP）上人为和自然颗粒物的高排放，研究2013年冬季德里细颗粒物（PM2.5）和可吸入颗粒物（PM10）的特征，包括其形态、物理和化学特性等非常重要。细颗粒物（PM2.5）和可吸入颗粒物（PM10）（连续）的平均质量浓度分别为117.6±79.1和191.0±127.6μg m(-3)，而粗模态（PM10 - 2.5）颗粒物的PM质量为73.38±28.5μg m(-3)。在同一时期，对PM2.5进行了离线重量监测以进行形态分析，其浓度比连续测量高出约37%。对收集的滤膜上的碳质颗粒物如有机碳（OC）和元素碳（EC）进行了分析，白天它们的平均浓度分别为33.8和4.0μg m(-3)，而夜间分别为41.2和10.1μg m(-3)。白天和夜间的平均OC/EC比分别为8.97和3.96，表明白天形成了二次有机气溶胶。研究了有效碳比以观察气溶胶对气候的影响，其在夜间和白天的平均值分别为0.52和1.79，表明在研究区域上空的大气中分别以吸收型和气溶胶散射型为主。单个颗粒的元素分析表明，硅是最丰富的元素（约37% - 90%），其次是氧（氧化物）和铝。研究了颗粒的圆形度和长宽比，这表明颗粒不是完美球形且在任何方向上都不拉长。轨迹分析表明，在2月和3月，气团似乎是从中东地区以及邻国和塔尔沙漠地区输送过来的，而在1月气团来自东北方向，这导致了细颗粒物的高浓度。
