title: Ambient particulate matter and carbon monoxide at an urban site of India: Influence of anthropogenic emissions and dust storms.
abstract: Continuous measurements of PM2.5, PM10and CO were conducted at an urban site of Udaipur in India from April 2011 to March 2012. The annual mean concentrations of PM2.5,PM10and CO were 42 ± 17 μg m-3, 114 ± 31 μg m-3and 343 ± 136 ppbv, respectively. Concentrations of both particulate and CO showed high values during winter/pre-monsoon (dry) period and lowest in the monsoon season (wet). Local anthropogenic emission and long-range transport from open biomass burning sources along with favourable synoptic meteorology led to elevated levels of pollutants in the dry season. However, higher values of PM10/PM2.5ratio during pre-monsoon season were caused by the episodes of dust storm. In the monsoon season, flow of cleaner air, rainfall and negligible emissions from biomass burning resulted in the lowest levels of pollutants. The concentrations of PM2.5, PM10and CO showed highest values during morning and evening rush hours, while lowest in the afternoon hours. In winter season, reductions of PM2.5,CO and PM10during weekends were highest of 15%, 13% and 9%, respectively. In each season, the highest PM2.5/PM10ratio coincided with the highest concentrations of pollutants (CO and NOX) indicating predominant emissions from anthropogenic sources. Exceptionally high concentrations of PM10during the episode of dust storm were due to transport from the Arabian Peninsula and Thar Desert. Up to ∼32% enhancements of PM10were observed during strong dust storms. Relatively low levels of O3and NOxduring the storm periods indicate the role of heterogeneous removal.
authors.affiliation: Physical Research Laboratory, Ahmedabad, 380009, India. Electronic address: yadavravi38@gmail.com.
authors.forename: Ravi
authors.initials: R
authors.lastname: Yadav
authors.affiliation: Physical Research Laboratory, Ahmedabad, 380009, India.
authors.forename: L K
authors.initials: LK
authors.lastname: Sahu
authors.affiliation: Indian Institute of Tropical Meteorology, Pune, 411008, India.
authors.forename: G
authors.initials: G
authors.lastname: Beig
authors.affiliation: Physical Research Laboratory, Ahmedabad, 380009, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Tripathi
authors.affiliation: Department of Physics, Mohanlal Sukhadia University, Udaipur, 313001, India.
authors.forename: S N A
authors.initials: SNA
authors.lastname: Jaaffrey
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring; D007194:India; D052638:Particulate Matter / Q000032:analysis*; D012621:Seasons; D001335:Vehicle Emissions / Q000032:analysis
chemical_list: D000393:Air Pollutants; D004391:Dust; D052638:Particulate Matter; D001335:Vehicle Emissions; D002248:Carbon Monoxide
keywords: Biomass burning; Carbon monoxide; Dust storm; India; Particulate matters