The New York Metropolitan Area (NYMA) is home to more than 20 million people and experiences high levels of pollution. In the summer of 2021, 7 of 11 monitoring stations in the NYMA reported ozone levels in exceedance of the EPA National Ambient Air Quality Standard (last accessed 2022 June 2). Total PM2.5 loading has improved significantly in recent decades due to air quality regulations, but a growing contribution of organic matter to the total aerosol burden may have implications for particle toxicity and regulatory policy. Encompassing rural, urban, and marine environments, the NYMA is subject to a complex mixture of emissions, chemistry, and coastal meteorology that ultimately determine the production and fate of harmful pollutants.
The Greater New York Oxidant Trace Gas Halogen and Aerosol Airborne Mission (GOTHAAM) is an NSF-funded investigation of the detailed chemical processes controlling atmospheric composition in the NYMA. State-of-the-art in situ instrumentation will be deployed on the NCAR/NSF C-130 aircraft in July and August – rescheduled to 2025 – to address four related objectives.
GOTHAAM observations will improve understanding of formation of O3 and PM2.5 pollution in the NYMA. By sharing and disseminating results, GOTHAAM will help air quality agencies in the region and other similar mega cities take action to mitigate harmful pollution.
The NCAR/NSF C-130 payload is optimized to address GOTHAAM objectives. Multi-instrument VOC measurements will thoroughly characterize VOC sources and oxidation products in the high and intermediate volatility range (Objectives 1, 2, 3). Direct observations of key oxidants will constrain the lifetime of reactive carbon and nitrogen (Objective 3). Measurements of gas-phase aerosol precursors and aerosol composition will elucidate major pathways leading to secondary pollutants (Objectives 2, 3). Simultaneous observations of halogenated gases, sulfur-containing gases, and aerosol properties will illuminate how the marine atmosphere processes urban outflow (Objectives 3, 4). In combination, the GOTHAAM payload can yield a comprehensive picture of atmospheric chemistry in the NYMA.
|OH, HO2, RO2, H2SO4||NO3- CIMS||Lee Mauldin||CU Boulder|
|oVOCs, halogens, ClNO2, HONO, N2O5, etc||I- CIMS||Joel Thornton||U Washington|
|VOCs||PTR-TOF Vocus||Joel Thornton||U Washington|
|VOCs||Mini WAAS||Eric Apel||NCAR|
|Organic gases||TOGA-TOF||Eric Apel||NCAR ACOM|
|HCHO||ISAF||Reem Hannun / Glenn Wolfe||UMD / NASA|
|NOx, ∑NOy, O3||Chemiluminescence||Ale Franchin||NCAR ACOM|
|Speciated PANs||TD-CIMS||Frank Flocke||NCAR ACOM|
|GHG/CO/SO2||Picarro||Teresa Campos||NCAR ACOM|
|Individual particle composition, including sea salt||ATOF-MS||Kerri Pratt||U Michigan|
|SOA composition||AMS||Delphine Farmer||CSU|
|Aerosol impaction collector||TRAC||Daniel Knopf||Stony Brook|
|Aerosol size distributions||UHSAS, cloud probe||n/a||NCAR EOL|
|J-values||HARP actinic flux||Samuel Hall||NCAR ACOM|
All measurements are in situ. Gas-phase observations include speciated VOC, speciated and total reactive nitrogen, radicals (OH, HO2, RO2), greenhouse gases, sulfur and halogen-containing compounds, and more. Aerosol measurements include single-particle and bulk chemical composition, physical properties, and size distributions.
With 150 flight hours, GOTHAAM will generate a high-resolution 4-D portrait of atmospheric composition and processes in the NYMA during the peak ozone season. Flights will include a combination of Lagrangian and Eulerian strategies and focus on the same domain as the NEC-AQ-GHG Cessna research aircraft. Missed approaches at designated airports will provide full vertical profiles of short-lived reactive species and improve connections to ground monitoring networks. Flights will also exploit natural variability in near-surface wind patterns to probe the various chemical regimes both independently and in combination (e.g., urban plume outflow over land vs. over water). Multi-scale models, including F0AM, CMAQ, and GEOS-Chem, will support forecasting and analysis
The next-generation instrumentation on GOTHAAM will provide an unprecedented dataset detailing NYMA atmospheric composition. Analyses will reveal the controls on O3 and PM formation, informing air quality stakeholders in both NY and other megacities. Regional and global models struggle in coastal regions, and GOTHAAM observations can serve as a benchmark constraint for pinpointing model shortfalls and testing new parameterizations. Finally, with potential concurrent sampling under TEMPO, GOTHAAM data will serve as a ground-truth resource for validation of satellite retrievals and applications of satellite data to studies of emissions and chemistry.