Vehicle Ammonia Emissions Measured in An Urban Environment in Sydney, Australia, Using Open Path Fourier Transform Infra-Red Spectroscopy
- Resource Type
- Authors
- David W. T. Griffith; Clare Paton-Walsh; Hugh I Forehead; Travis A Naylor; Frances Phillips; John Kirkwood
- Source
- Atmosphere
Volume 10
Issue 4
Atmosphere, Vol 10, Iss 4, p 208 (2019)
- Subject
- inorganic chemicals
Atmospheric Science
010504 meteorology & atmospheric sciences
Ammonium nitrate
lcsh:QC851-999
010501 environmental sciences
Environmental Science (miscellaneous)
ammonia
01 natural sciences
carbon monoxide
law.invention
Atmosphere
Ammonia
chemistry.chemical_compound
law
open path FTIR spectroscopy
parasitic diseases
NH3
Air quality index
NOx
0105 earth and related environmental sciences
particulate matter
emissions
Particulates
air quality
CO
chemistry
Environmental chemistry
vehicle
Carbon dioxide
Catalytic converter
Environmental science
lcsh:Meteorology. Climatology
urban
- Language
- ISSN
- 2073-4433
Airborne particulate matter (PM) is a major health risk in urban settings. Ammonia (NH3) from vehicle exhaust is an under-recognised ingredient in the formation of inorganic PM and there remains a shortage of data to properly quantify the role of NH3 from vehicles in PM formation. An Open-path Fourier transform infra-red (OP-FTIR) spectrometer measured atmospheric NH3, carbon monoxide (CO) and carbon dioxide (CO2) at high temporal resolution (5 min) in Western Sydney over 11 months. The oxides of nitrogen (NO2 and NO
NOx) and sulphur dioxide (SO2) were measured at an adjacent air quality monitoring station. NH3 levels were maxima in the morning and evening coincident with peak traffic. During peak traffic NH3:CO ratio ranged from 0.018 to 0.022 ppbv:ppbv. Results were compared with the Greater Metropolitan Region 2008 (GMR2008) emissions inventory. Measured NH3:CO was higher during peak traffic times than the GMR2008 emissions estimates, indicating an underestimation of vehicle NH3 emissions in the inventory. Measurements also indicated the urban atmosphere was NH3 rich for the formation of ammonium sulphate ((NH4)2SO4) particulate was SO2 limited while the formation of ammonium nitrate (NH4NO3) was NH3 limited. Any reduction in NOx emissions with improved catalytic converter efficiency will be accompanied by an increase in NH3 production and potentially with an increase in NH4NO3 particulate.