CPO’s Atmospheric Chemistry, Carbon Cycle and Climate (AC4) Program supported a new scientific study that measured Particulate Matter (PM) from New York City (NYC) during the summer of 2022 as part of the NYC-METS (New York City metropolitan Measurements of Emissions and TransformationS) field campaign. AC4 funded this project through two different grants awarded to Yale University and Aerodyne Research Inc. focused on understanding the chemical composition of urban atmospheres. This work contributed to a large-scale coordinated measurement effort, as part of the NOAA-led AEROMMA field campaign, and its interagency umbrella, AGES+ (AEROMMA+CUPiDS, GOTHAAM, EPCAPE, STAQS). Atmospheric aerosols, specifically particulate matter with a diameter of 2.5 μm or less (PM2.5), are significant air pollutants with adverse implications for human health and climate. This study emphasizes the importance of understanding the sources and factors influencing aerosol concentrations, as the composition poses challenges for air quality policies in NYC.
The results, published in ACS ES&T Air, show a notable shift in the composition of summertime particle pollutants in NYC from inorganic to organic (80-83%). The researchers found that most of these organic pollutants come from secondary sources, or in other words, they are created through chemical transformations in the atmosphere rather than emitted directly from a source. Primary sources, such as cooking-related emissions, constitute a smaller proportion of the organic pool. Secondary pollutants show a strong temperature sensitivity, posing a risk of exacerbating air quality issues in the context of warming temperatures and heat events in NYC. Despite improvements in PM2.5 concentrations over the 21st century, the persistence of these secondary organic aerosols and the possibility for intensification underscores the need for ongoing monitoring and policy adjustments to address evolving air quality issues in densely populated urban areas like NYC.
For more information, contact Clara Deck.
Image credit: Drew Gentner, Yale University