AEROMMA Goals

Objectives

Recent National Oceanic and Atmospheric Administration (NOAA) Chemical Sciences Laboratory (CSL) science foci are also current topics that have generated broad interest in the atmospheric science, air quality, and climate communities: changing emissions in urban areas, advances in marine and remote atmosphere chemistry, and satellite data assessment. Due to our position at the forefront of this research, NOAA CSL, its collaborators and stakeholders have an unparalleled opportunity to lead efforts to (1) understand the changing paradigms in emissions and the future of urban air quality, (2) refine our understanding of the marine atmosphere, and (3) validate remote sensing capabilities from satellites in urban and remote atmospheres.

To achieve these goals, NOAA CSL will conduct the Atmospheric Emissions and Reactions Observed from Megacities to Marine Areas (AEROMMA) mission, a multi-agency, multi-platform experiment planned for summer 2023 to provide new observations from megacities to marine environments. AEROMMA will bring together airborne, surface, and satellite observing systems, and state-of-the-art air quality and climate models. Major objectives of the AEROMMA project include:

  • Timely information to environmental managers and stakeholder groups on emissions that impact climate and air quality;
  • Improvement in the representation of emissions and chemical and physical processes in the next generation NOAA weather-chemistry models;
  • Reductions in global climate model uncertainties through provisions of improved observational constraints;
  • Quantification of the emissions of VCPs (Volatile Chemical Products), cooking, mobile and other trace gas sources in urban areas;
  • Accurate representation of chemistry and aerosol microphysics in the marine atmosphere;
  • First comprehensive aircraft observations of atmospheric composition when TEMPO (Tropospheric Emissions: Monitoring Pollution) is operational;
  • Value assessment and risk reduction for future satellite missions such as NOAA GeoXO (Geostationary Extended Observations).

Science Questions

Urban

AEROMMA will determine organic emissions and chemistry, including of understudied VCPs and cooking in the most populated urban areas in the United States, to better understand the impact on ozone and aerosol formation, and to study their relative importance on urban air quality compared to other sources of VOCs such as from energy-related, and biogenic sources.

  1. How well do current emission inventories quantify the flux of anthropogenic VOC emissions over North American cities, including VCPs, mobile sources, cooking, and industrial facilities?
  2. How does the relative distribution of VOC emissions vary by city and population density, influencing the ratio of VCP to mobile source emissions?
  3. What chemical tracers can be used to source apportion VOCs amongst VCPs, energy-related, cooking, and biogenic sources?
  4. How have emissions changed between AEROMMA and previous urban measurements (e.g., NEAQS 2002, ICARTT 2004, TEXAQS 2006, CalNex 2010, SENEX 2013, WINTER 2015, NYICE/LISTOS 2018, FIREX-AQ 2019, SUNVEx 2021, etc.)?
  5. What is the composition of gas- and aerosol phase organics in the urban atmosphere, including aromatics, alkanes, terpenes, cycloalkanes, oxygenated VOCs (including water-soluble organics such as alcohols, esters, glycols, and glycol ethers), and organic aerosol?
  6. How well do reduced chemical mechanisms used in models represent the current composition of gas- and aerosol phase organics in the urban atmosphere including oxygenated VOCs from VCPs?
  7. What is the relative role of anthropogenic (including VCPs and cooking) versus biogenic VOCs on ozone and SOA formation, and how does this vary between vegetated and non-vegetated regions?
  8. How do organics affect the evolution of particle size, number distribution, and aerosol optical properties (e.g., brown carbon) in urban outflow, and to what extent does urban outflow contribute to cloud condensation nuclei (CCN) formation?
  9. How well do models represent the oxidation chemistry of understudied oxygenated VOCs from VCPs and how does this impact simulated ozone and SOA formation in and downwind of urban regions?

AEROMMA will determine reactive nitrogen emissions and chemistry in major urban corridors (i.e., urban core to suburban and outlying rural areas) to understand the current importance of combustion and non-combustion sources, continue the trend analysis and determine changes in the reactive nitrogen cycle chemistry and its influence on ozone and aerosol formation.

  1. How well do current emission inventories quantify the flux of anthropogenic nitrogen oxides (NOx = NO + NO2) over North American cities, including from mobile sources, buildings, industrial facilities, and outlying agricultural regions and power generation?
  2. How have NOx emissions changed between AEROMMA and previous urban measurements (e.g., NEAQS 2002, ICARTT 2004, TEXAQS 2006, CalNex 2010, SENEX 2013, WINTER 2015, NYICE/LISTOS 2018, FIREX-AQ 2019, SUNVEx 2021, etc.)?
  3. What is the relative role of combustion (e.g., mobile sources) versus non-combustion sources (e.g., agricultural soils) of NOx, nitrous acid (HONO), ammonia (NH3), and VOCs on ozone and particulate formation?
  4. How do the formation rates of ozone and particulate matter in urban outflow evolve from high to low NOx regions? What is the spatial distribution of high or low NOx regimes?
  5. What is the speciation of oxidized reactive nitrogen in the continental background and in urban outflow in 2023 and how well is it represented in models?
  6. What is the lifetime of NOx, and what are its major loss processes in 2023? How does this relate to and inform diurnally resolved remote sensing measurements?
  7. How have changes in particulate matter composition, mass and surface area altered heterogeneous processes, particularly with respect to nitrogen oxides?
  8. What is the distribution of nitrogen oxides, VOCs and other short-lived primary pollutants in urban areas, and how does this relate to economic and racial disparities at urban scale?

AEROMMA will determine the co-benefits between managing air quality and the carbon cycle. Investigate urban and coastal meteorology, to better understand extreme heat on urban air quality. Assess how the emissions in U.S. urban areas recover after the COVID-19 outbreak.

  1. How well do current emission inventories quantify the flux of anthropogenic CO2 and CH4 emissions over North American cities, including from mobile sources, buildings, industrial facilities, natural gas infrastructure, and landfills?
  2. How does the flux of CO2 and CH4 emissions vary between North American cities, including as a function of population density and age of energy infrastructure?
  3. How does extreme heat affect urban and coastal meteorology, photochemistry, and ozone and aerosol formation?
  4. How does the urban canopy affect urban heat islands, land-sea breezes, and planetary boundary layer (PBL) dynamics?
  5. How have emissions recovered after the decrease in economic activities during COVID-19?
  6. Have the distribution and magnitude of VCP, mobile source, and industrial emissions changed; is there a new normal after COVID-19?
  7. Are there differences in chemistry leading to ozone and secondary PM2.5 compared to the lower emission and different VOC/NOx ratios measured during the NOAA COVID-AQS 2020 campaign?

Urban Marine Interface

AEROMMA will provide observations at the interface of the marine atmosphere and the urban airshed to quantify what impact marine emissions have on urban air quality and composition, and the impact of urban outflow on marine chemistry. Observations of SO2 and aerosol abundance will resolve the relative contributions to SO2, sulfate aerosols, and CCN from biogenic and anthropogenic sources.

  1. How does anthropogenic NOx impact oxidation of biogenic sulfur and the product distributions of secondary species in the marine atmosphere?
  2. What impacts do marine halogens have on the atmospheric oxidant budget in coastal urban reas through the key marine reactive species, e.g. ClNO2, Cl2, and BrO?
  3. Are marine gases important factors for ozone formation in coastal urban regions?
  4. How is the baseline continental O3 controlled by O3 imported from onshore flow?

Marine

AEROMMA will exploit the range and capabilities of the NASA DC-8 to sample the pristine marine atmosphere in regions with (1) limited to moderate impacts from anthropogenic sources, (2) high atmospheric burden from biogenic sulfur emissions, (3) stable meteorology, (4) a well-defined marine boundary layer, and (5) varying cloud fields. AEROMMA Marine science foci will include three primary themes.

Investigation of the emissions and chemistry in the remote marine atmosphere that drive the formation of secondary products and marine aerosols. Flux observations will be used to better quantify the air-sea exchange of VOCs, NOx, O3, and halogen species to better understand the atmospheric budget of gas-phase precursor species in the remote atmosphere.

  1. What are the sources of VOCs and volatile sulfur in the remote marine atmosphere?
  2. How well do we understand the net oceanic flux of biogenic sulfur?
  3. How do primary oceanic emissions of sea spray impact the marine aerosol burden, spatial distribution and properties?
  4. At what rates are atmospheric gases and aerosol deposited to the ocean's surface?
  5. How important is NOx that is emitted from the sea surface or generated in the marine boundary layer compared to transported NOx?
  6. What are the emissions, fluxes, chemistry and transport of organic and inorganic marine halogen species?

Observations to better characterize the marine sulfur oxidation cycle and secondary aerosol formation and dependencies on key parameters such as temperature, NOx, and background aerosol.

  1. Do we sufficiently understand oxidation of biogenic sulfur and VOCs in the remote marine atmosphere?
  2. What are the key details linking the oxidation of biogenic marine emissions to aerosol production and growth? Do biogenic species other than sulfuric acid generate new particles in the MBL or free troposphere?
  3. What are the processes that drive the removal of gases and aerosols throughout the marine boundary layer?

Observations to better characterize the marine sulfur oxidation cycle and secondary aerosol formation and dependencies on key parameters such as temperature, NOx, and background aerosol.

  1. What fraction of the organic aerosol is primary versus secondary at various time scales?
  2. How well do current models represent primary and secondary marine aerosols and their radiative properties, and what are the largest associated uncertainties?
  3. How do aerosol optical properties evolve due to secondary production and particle phase transitions?
  4. What are the sources of new particles in the remote troposphere, how rapidly do they grow to CCN-active sizes, and how well are these processes represented in CCMs?

Satellite

AEROMMA will provide observations for proving and reducing risk of TEMPO, JPSS, and GOES-R science and near real-time trace gas and aerosol products.

  1. How well does the diurnal cycle of geostationary trace gas (NO2, HCHO, O3) and aerosol (AOD and ALH) products correspond to observations from heavy-lift in-situ aircraft, airborne remote sensing, and ground-based observing networks (e.g., Pandonia and AERONET)?
  2. How does the NOx lifetime affect the interpretation of satellite retrievals of nitrogen dioxide (NO2) as a constraint on urban to rural NOx emission inventories?
  3. How well do TEMPO science and near real-time data products correspond to existing polar-orbiting and geostationary satellites, including Sentinel-5P/TROPOMI, NOAA-20/OMPS, NOAA-20/VIIRS and GOES-16/17 ABI over urban and marine areas?
  4. How well can TEMPO tropospheric ozone and aerosol layer height be derived over urban, coastal, and marine areas to improve vertical information of atmospheric composition?
  5. What is the value of extending NOAA JPSS and GeoXO spaceborne infrared remote sensing capabilities, along with a UV-VIS spectrometer, to include greenhouse gases and other reactive gas and aerosol precursors for monitoring emissions, air quality, and climate?

AEROMMA will provide field observations for evaluating NOAA’s next generation weather-chemistry models and chemical data assimilation of atmospheric composition satellite data.

  1. Does chemical data assimilation of TEMPO and GOES-R trace gas and aerosol products help improve near real-time emissions updating and air quality forecasting capabilities?
  2. How well do next generation NOAA weather-chemistry models using the FV3 dynamical core (e.g., RRFS-CMAQ) perform when evaluated with aircraft and geostationary/polar-orbiting satellite observations?
  3. How can NOAA field campaigns lead to more direct improvements of NOAA operational air quality models using tools such as MELODIES MONET?