10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Exploring the Chemical Composition of Gas and Aerosol Phase Measurements from FIGAERO-ToF-CIMS in Beijing Using Positive Matrix Factorisation
ARCHIT MEHRA, Manjula Canagaratna, Stephen Worrall, Asan Bacak, Thomas Bannan, Michael Priestley, James Lee, Freya Squires, James Hopkins, Rachel Dunmore, Jacqueline F. Hamilton, Eloise Slater, Lisa Whalley, Yele Sun, Pingqing Fu, James Allan, Carl Percival, John Jayne, Douglas Worsnop, Hugh Coe, University of Manchester
Abstract Number: 529 Working Group: Air Quality in Megacities: from Sources to Control
Abstract Globally, air quality in megacities such as Beijing is of increasing interest due to its impact upon health. With a complex mixture of emission sources, it is challenging to understand the key drivers of the pollution; however it is vital to do so for effective and relevant policy implementation. The Air Pollution and Human Health Beijing (APHH-Beijing) project is a joint UK-China collaboration which aims to identify both the concentrations and sources of urban pollution in Beijing and people’s exposure to this pollution in order to further understand its impact upon health. Within this project, AIRPOLL-Beijing aims to identify sources and emissions of air pollutants while AIRPRO focuses on air pollution processes in Beijing. Two intensive periods of measurement in Beijing were carried out in November-December 2016 and May-June 2017. A wide range of instrumentation was deployed at the Institute of Atmospheric Physics, an urban measurement site in North Beijing between the third and fourth ring roads. Here we present observations from the FIGAERO-ToF-CIMS which enables simultaneous detection of the molecular composition of the gas and particle phases through use of a Filter Inlet for Gases and AEROsols (FIGAERO) coupled to a time of flight chemical ionisation mass spectrometer (TOF-CIMS). Observed species are detected as adducts with the reagent ion, Iodide, which is highly sensitive and selective for multifunctional oxidised organic molecules. Positive Matrix Factorisation (PMF) is applied to this data to probe the relative contributions of different sources and processes to the pollution in Beijing and how these source profiles vary temporally during the campaigns. The analysis has been able to identify factors with varying volatility in the aerosol phase, alongside factors potentially relating to biomass burning, vehicular emissions and secondary processes.