View of New York City skyline from the Manhattan field site located at The City College of New York (CUNY) Advanced Science Research Center (ASRC)
Pollution in urban centers has historically been dominated by combustion-related sources of emissions, like motor vehicles, but recent air quality research demonstrates that emissions from combustion-related sources are declining while non-combustion-related emissions are increasing from sources like volatile chemical products (VCPs). This trend is evident in data from certain types of volatile organic compounds (VOCs), which are emitted in vehicle exhaust as well as household products and commercial or industrial applications.
These complex non-combustion-related sources include chemicals used for construction materials, solvents, paints, consumer and hygiene products, and petroleum-derived products. They increasingly impact urban air quality as primary pollutants and as reactive precursors to secondary air pollution. In general, organic compounds and VOCs are precursors to secondary organic aerosol (SOA) and ozone, which are created in the atmosphere instead of being emitted directly. More studies on non-traditional pollutant sources are being conducted, and findings indicate that mitigating these sources is increasingly important for improvement of urban air quality.
To better understand these new sources, researchers from Yale University, Aerodyne Research Inc., University of Texas at Austin, University of Michigan, and College of William and Mary are conducting a field campaign in the Greater New York City Metropolitan Area, funded by CPO’s Atmospheric Chemistry, Carbon Cycle and Climate (AC4) program. They will gather data on real-world vehicular and non-vehicular VOC emissions, and the products of their chemical reactions in the atmosphere. Researchers from the University of Iowa with funding from other federal agencies are also a part of this measurement campaign.
For the campaign, a combination of state-of-the-art instruments using spectroscopy-, chromatography-, and mass spectrometry-based techniques are taking atmospheric measurements to characterize emissions and oxidative aging of various types of VOCs and greenhouse gases. The campaign comprises online measurements, which measure the air directly from a New York rooftop, and offline measurements, which return samples to a lab for more detailed analysis later.
Left: Researcher installing atmospheric measurement instruments at the Manhattan site. Right: Researchers and instrumentation at the downwind Yale Coastal Field Station in Connecticut.
Measurements will capture the composition and dynamics of non-traditional urban emissions, contributing to a growing body of research supported by the AC4 program to improve local and regional understanding of the urban atmosphere. In turn, these emission measurements will be integrated into regional chemistry and emission models to enhance air quality predictions and forecasting, and help locate the most effective targets for emissions reduction.
While the campaign was funded in fiscal year 2020, data collection was delayed to summer 2022 due to COVID-19 restrictions. Currently, there are two deployments, one in New York City, hosted at CUNY-ASRC, and another at a site downwind in Guilford, Connecticut. They operate from July 8, 2022 through August 7, 2022.
AC4 is a competitive research program that incorporates research on atmospheric chemistry and the carbon cycle. In collaboration with the NOAA Laboratories and the academic community, the AC4 program supports research to determine the processes governing atmospheric concentrations of trace gases and aerosols in the context of the Earth System. The program aims to contribute a process-level understanding of the Earth System through observation, modeling, analysis, and field studies to support the development and improvement of models, and to inform carbon and air pollution management efforts.