GOTHAAM: The Science

Greater New York Oxidant Trace gas Halogen and Aerosol Airborne Mission
Summer 2023

The New York City region is comprised of:

  • Biogenic/terrestrial (biogenic volatile organic compounds are dominant)
  • Urban/industrial (NOx, Volatile Consumer Products (VCPs), VOC from fossil fuels, potentially leading to high O3)
  • Marine (halogen emissions)

Each system has characteristic trace species emissions that uniquely impact chemistry.

1. Biogenic summertime emissions surrounding NYC are very large; temperate forest coverage of the surrounding regions (NY, NJ, CT, MA, PA) is greater than 20 million hectares.


2. Nighttime Cl2 in the marine layer can be very enriched in the NY region (black line) compared to the west coast (red line), leading to rapid oxidation at sunrise.

3. Summertime flow is often from the S-W quadrant; polluted quadrant for NY Metropolitan area (>20 million people impacted).

4. Urban plume (with high NOx, anthropogenic VOCs, VCPs, aerosol) mixes with Biogenic and Marine systems.

What makes GOTHAAM unique?

  • Biogenic precursors to SOA are among the highest outside SE US.

    oProposed diel study of night-into-day chemical mechanisms would be a first, especially with proposed instrumentation.

  • The NYC region is the most densely populated region in CONUS (>23 million).

  • There has not been a recent comprehensive airborne study of the atmospheric chemical processes focusing on this region.

  • GOTHAAM’s integrated state-of-the-art chemistry payload.


Recent VOC-centric aircraft campaigns* underscore the lack of information in the NE US (Chen et al., 2019). GOTHAAM  encompasses VOC studies.

*SOAS, NOMADDS cover the similar region as SENEX

Biogenic derived SOA (BSOA) in July 2013 illustrates the significant production in the GOTHAAM region. There is a large difference between the NYC region and the central/western US. (Carlton et al., 2018)

GOTHAAM Scientific Objectives

Objective 1. Quantify the relative contributions from the various volatile organic compound (VOC) sources (biogenic, fossil fuel, combustion, consumer products) and how they contribute to chemical reactivity.


Objective 2. Determine the relative potential contribution of each VOC class to secondary organic aerosol (SOA) as the anthropogenic plume evolves.

Objective 3. Quantify the relative importance of the various oxidation processes for both gas phase and aerosol species, and how the relative importance of these processes vary across the diel cycle and as a function of the chemical system (biogenic/urban/marine).

Objective 4. Investigate how nighttime chemical processes influence the subsequent day’s initial chemical composition.