Final Report Summary - ALP-AIR (Atmospheric flux-measurements of precursor-gases for air-quality and climate research)
The main goal of this proposal was to develop an experimental framework for innovative novel experimental techniques allowing to quantify the chemical composition of the atmosphere, with a particular focus on surface- atmosphere exchange. The issue of surface – atmosphere exchange turns out to be quite complex, and despite significant advances in the field of atmospheric sciences, research is needed to reduce uncertainties in the quantitative understanding of chemical drivers influencing climate and air quality (US National Acadamy of Science, 2016).
Key activities for AlpAIR included the development of a comprehensive research program allowing the investigation of the exchange of reactive (e.g. NMVOC (non-methane volatile organic compounds), NOx (nitrogen oxides)) and non-reactive (H2O, CO2) trace constituents at the surface-atmosphere interface based on novel time-of-flight mass spectrometry, coupled to chemical ionization, in combination with conventional absorption spectroscopy. The first phase of the proposal included testing of a novel Proton-transfer-reaction time of flight mass spectrometer (PTR-qITOFMS), and coupling it to parallel micrometeorological observations of heat, water and carbon dioxide at an Alpine location. We were able to achieve an unprecedented limit of detection for atmospheric flux measurements of NMVOCs using PTR-qITOFMS, and these results were presented at the 7th International Conference on Proton-transfer-reaction mass spectrometry and it’s Applications (Graus et al., 2016). In addition, it was possible to combine these measurements with fast in-situ techniques for the detection of nitrogen oxides, in particular a chemiluminescence method for NO and NOx, and a cavity ring down spectrometer suitable for fast NO2 measurements. Results from these activities have been the subject of several Bachelor, Master and one Phd thesis.
During the second phase of AlpAir the observational capacity was devoted to a comprehensive research campaign, the Innsbruck Air quality study (INNAQS), which was organized at the Institute for Atmospheric and Cryospheric Sciences in 2015, and focused particularly on atmosphere-surface exchange measurements above an urban location. The campaign included comprehensive measurements of reactive and not reactive trace gases (NMVOC, NOx, CO, CO2, O3, CH4, H2O) as well as aerosols and submicron aerosol fluxes, conducted as part of a collaborative effort with the University of Bayreuth and the University of Münster. First results from INNAQS have recently been accepted for publication in Nature Scientific Reports (Karl et al., 2017). The scientific motivation of the study was that there is growing concern about NOx pollution becoming a primary environmental problem across Europe, indicating substantial uncertainty in our quantitative understanding of the anthropogenic perturbation of the nitrogen cycle. Based on a unique set of eddy covariance measurements of NOx, CO, CO2 and NMVOC, we are able to put quantitative and scalable top-down constraints on urban atmospheric NOx fluxes for the first time, and examine impacts on atmospheric chemistry. Our results show substantially larger fluxes of traffic related NOx emissions (up to a factor of 4) compared to projections in current atmospheric chemistry and climate models. We were able to rationalize these results in context of the large penetration of Diesel operated vehicles in Austria. Based on these observations we were also able to investigate the impact of imposed future regulatory actions on perturbations of the local ozone forming potential in a real-world scenario based on the weekend effect. As such these findings have ramifications for many other parts of the world suffering from NOx pollution. These results also have high societal relevance as current trends across European air quality networks show that regulatory thresholds of NO2 are violated at many stations and policy decisions are being discussed that would limit the proliferation of Diesel cars throughout Europe.
The performed activities will make an important contribution to a better understanding of air quality and climate interactions in an Alpine region and help the local Air quality management group in their continued effort to improve decision making supported by scientific advance through providing updated emission inventories for the state of Tyrol. These results though are not only relevant for local air quality issues. For example, the United States environmental protection agency’s (US EPA) notice of violation of the Clean Air Act to a German automaker regarding Diesel engines has sparked a number of new real world driving (RDE) emission tests across Europe, which show significant manufacturer and vehicle specific variability. Given the projected dramatic increase of Diesel fuels (including renewable bio-diesel) worldwide, and potential growth markets across Asia, our tested methodology for obtaining top-down constraints on the actual atmospheric flux of trace gases and aerosols should therefore be of interest to a wide scientific audience in atmospheric and environmental sciences, and of immediate relevance to the air quality and policy making community. Based on activities conducted as part of the AlpAir project it was possible to leverage additional funding, and establish a new urban observatory, the Innsbruck Atmospheric Observatory (IAO), which is currently in the initial phase and augment observational facilities allowing to study urban micrometeorological and air quality related science questions in an Alpine environment.
Key activities for AlpAIR included the development of a comprehensive research program allowing the investigation of the exchange of reactive (e.g. NMVOC (non-methane volatile organic compounds), NOx (nitrogen oxides)) and non-reactive (H2O, CO2) trace constituents at the surface-atmosphere interface based on novel time-of-flight mass spectrometry, coupled to chemical ionization, in combination with conventional absorption spectroscopy. The first phase of the proposal included testing of a novel Proton-transfer-reaction time of flight mass spectrometer (PTR-qITOFMS), and coupling it to parallel micrometeorological observations of heat, water and carbon dioxide at an Alpine location. We were able to achieve an unprecedented limit of detection for atmospheric flux measurements of NMVOCs using PTR-qITOFMS, and these results were presented at the 7th International Conference on Proton-transfer-reaction mass spectrometry and it’s Applications (Graus et al., 2016). In addition, it was possible to combine these measurements with fast in-situ techniques for the detection of nitrogen oxides, in particular a chemiluminescence method for NO and NOx, and a cavity ring down spectrometer suitable for fast NO2 measurements. Results from these activities have been the subject of several Bachelor, Master and one Phd thesis.
During the second phase of AlpAir the observational capacity was devoted to a comprehensive research campaign, the Innsbruck Air quality study (INNAQS), which was organized at the Institute for Atmospheric and Cryospheric Sciences in 2015, and focused particularly on atmosphere-surface exchange measurements above an urban location. The campaign included comprehensive measurements of reactive and not reactive trace gases (NMVOC, NOx, CO, CO2, O3, CH4, H2O) as well as aerosols and submicron aerosol fluxes, conducted as part of a collaborative effort with the University of Bayreuth and the University of Münster. First results from INNAQS have recently been accepted for publication in Nature Scientific Reports (Karl et al., 2017). The scientific motivation of the study was that there is growing concern about NOx pollution becoming a primary environmental problem across Europe, indicating substantial uncertainty in our quantitative understanding of the anthropogenic perturbation of the nitrogen cycle. Based on a unique set of eddy covariance measurements of NOx, CO, CO2 and NMVOC, we are able to put quantitative and scalable top-down constraints on urban atmospheric NOx fluxes for the first time, and examine impacts on atmospheric chemistry. Our results show substantially larger fluxes of traffic related NOx emissions (up to a factor of 4) compared to projections in current atmospheric chemistry and climate models. We were able to rationalize these results in context of the large penetration of Diesel operated vehicles in Austria. Based on these observations we were also able to investigate the impact of imposed future regulatory actions on perturbations of the local ozone forming potential in a real-world scenario based on the weekend effect. As such these findings have ramifications for many other parts of the world suffering from NOx pollution. These results also have high societal relevance as current trends across European air quality networks show that regulatory thresholds of NO2 are violated at many stations and policy decisions are being discussed that would limit the proliferation of Diesel cars throughout Europe.
The performed activities will make an important contribution to a better understanding of air quality and climate interactions in an Alpine region and help the local Air quality management group in their continued effort to improve decision making supported by scientific advance through providing updated emission inventories for the state of Tyrol. These results though are not only relevant for local air quality issues. For example, the United States environmental protection agency’s (US EPA) notice of violation of the Clean Air Act to a German automaker regarding Diesel engines has sparked a number of new real world driving (RDE) emission tests across Europe, which show significant manufacturer and vehicle specific variability. Given the projected dramatic increase of Diesel fuels (including renewable bio-diesel) worldwide, and potential growth markets across Asia, our tested methodology for obtaining top-down constraints on the actual atmospheric flux of trace gases and aerosols should therefore be of interest to a wide scientific audience in atmospheric and environmental sciences, and of immediate relevance to the air quality and policy making community. Based on activities conducted as part of the AlpAir project it was possible to leverage additional funding, and establish a new urban observatory, the Innsbruck Atmospheric Observatory (IAO), which is currently in the initial phase and augment observational facilities allowing to study urban micrometeorological and air quality related science questions in an Alpine environment.