Monitor for AeRosols and GAses - Fluxes of Inorganic and Organic compounds (MARGA-FIO)

点击翻译按钮获取中文摘要

Quantifying reactive gas and aerosol fluxes is vital to improve fundamental understanding of the Earth-System under multiple biogeochemical changes. To establish the next generation of models, it is necessary that we understand the interactions between chemical species. Emerging technology now provides the means to achieve this by building the first MARGA-FIO system. MARGA-FIO stands for "Monitor for AeRosols and GAses - Fluxes of Inorganic and Organic compounds". This new facility will integrate a two-channel two-column on-line ion chromatography system built around a recently launched instrument (2060 MARGA). The facility will be globally unique in incorporating two sampling channels and two environmental enclosures, to sample at two different heights, allowing flux determination of water soluble inorganic and organic atmospheric constituents.In flux-mode, MARGA-FIO will provide high resolution (hourly) concentration profiles so that the emission into the atmosphere or deposition to the surface can be measured. The trace gases measured cover ammonia (NH3), hydrochloric acid (HCl), nitric acid (HNO3), nitrous acid (HONO), sulphur dioxide (SO2), and the aerosol species ammonium (NH4+), sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), nitrate (NO3-) and sulphate (SO42-). The instrument will also have the capability to quantify fluxes of amines and organic acids (e.g. dicarboxylic acids), which will be a world first.In PM-mode, MARGA-FIO will measure online PM chemical composition at different size cut-offs (PM1, PM2.5 and PM10), in addition to the gas phase. This capability is unique as MARGA-FIO could chemically resolve >80% of the atmosphere-ecosystem exchange of PM and trace gases. Three examples of unique applications of the MARGA-FIO are:i) High resolution emission and deposition rates or "fluxes" of NH3 and HNO3, NH4+, NO3-, amines. This is important because nitrogen (N) pollution originating from agriculture (NH3) and transport/industry (nitrogen dioxide, NO2, HNO3) leads to complex atmospheric pollution impacting human health and damaging natural ecosystems. A low detection limit of MARGA-FIO will enable the study of pollutant deposition to our protected ecosystems. By measuring a range of key N compounds, the instrument will provide a holistic picture of the atmospheric impact of agriculture, transport and industry and detect where measures aimed at reducing the emission of one compound interacts with another (pollutant-swapping or co-benefits). ii) Fluxes of HCl and Cl : In recent studies of the NERC Air Pollution and Human Health research programmes in China and India, it became apparent that there is a gap in flux measurement capability for halogen species, particularly HCl and Cl- , both by UK and international research groups. High concentrations of chloride pollution are observed in Beijing and Delhi, which are associated to waste combustion processes. However, the sources and atmospheric pathways are poorly understood. MARGA-FIO would be the first instrument in the UK atmospheric research community which can quantify the fluxes of these important pollutants. It can also resolve concentration and fluxes of base cation (sodium, potassium, magnesium, calcium) which form part of the dust that troubles ODA countries (e.g. India, East Africa). iii) Organic pollutant fluxes: One of missing components in our understanding of the atmosphere is the rate of emission and deposition of organic PM constituents and gases, such as dicarboxylic acids. MARGA-FIO would offer a global step-change in quantitative measurement of previously un-measured processes at the surface-atmosphere interface. The data would complement existing capability with on-line Aerosol Mass Spectrometry available in the UK community, delivering much needed concentrations and emission rates / deposition velocities for constraining air quality and climate models.