2024 Program Topics

Our Technical Program Committee has developed several program topics for the 2024 ACM Conference. While the TPC is currently deciding initial speaker invitations, we will be opening abstract submissions for a podium or poster presentation in June.

Advances in understanding of tropospheric halogen chemistry

Session Chairs: Becky Alexander, University of Washington and Alfonso Saiz Lopez, Spanish National Research Council (CSIC)

Tropospheric reactive halogens (Cl, Br, I) impact the oxidation capacity of the atmosphere by acting as a sink for ozone and nitrogen oxides. Halogens alter the abundance of methane and the formation of secondary aerosols, all with potential implications for the radiative balance. Recent modeling, laboratory, and observational work highlight the importance of heterogeneous chemical reactions as both sources and sinks of halogens, but uncertainties remain in heterogeneous reaction mechanisms and rates. Heterogeneous chemistry occurs on both airborne aerosols as well as on the surface ocean and ice. In addition, iodine is known to be a source of new particles in the atmosphere but the exact molecular mechanisms are still uncertain. This session aims to explore our evolving mechanistic understanding of tropospheric reactive halogen chemistry in the gas and heterogeneous phases and highlight important mechanisms for controlling the budgets of reactive halogens and their impacts on the oxidative capacity of the atmosphere. We welcome modeling, field, and laboratory studies.

Atmospheric Chemistry in Public Health and Regulatory Applications

Session Chairs: Jim Kelly, US EPA and Emma D'Ambro, US EPA

Human health is greatly influenced by atmospheric pollutants such as ground level ozone (O3), particulate matter, and air toxics that can degrade lung function, cause cardiovascular disease, and are associated with other adverse health effects, including mortality. Chemical transport models (CTMs) and their chemical kinetic reaction mechanisms play a critical role in the development of abatement strategies for these pollutants. The development of these chemical mechanisms requires understanding of both emitted precursors and secondary products, and thus requires the compilation of knowledge from all areas of atmospheric chemistry: modeling at multiple scales, laboratory and field measurements, and computational calculations. The following session welcomes presentations on all aspects of atmospheric chemistry, and how they influence public health and regulatory applications.

BVOC multiphase chemistry - what do we know and what are we missing?

Session Chairs: Celia Faiola, UC Irvine and Domenico Taraborrelli, Forschungszentrum Jülich

Emissions of highly reactive biogenic volatile organic compounds (BVOCs) exceed those from anthropogenic sources on a global scale. Detailed gas-phase chemical mechanisms have been developed for a handful of representative species such as isoprene, DMS, and a few different monoterpenes, but it is unclear how well these mechanisms will predict this chemistry in a future climate where BVOC composition, emission rates, and the background environmental conditions will change. In particular, uncertainties remain about the chemistry of underrepresented compounds, unknown cross-reactions of complex BVOC mixtures, and novel mechanisms that emerge in less-studied environments or environmental contexts. This session will highlight recent advancements in multiphase oxidation of organics from biogenic sources centered on these major knowledge gaps.

Chemical Mechanism Development under Changing Regimes

Session Chairs: Luc Vereecken, Forschungszentrum Jülich and Rebecca Schwantes, NOAA Chemical Sciences Laboratory

Due to air pollution control and climate change mitigation strategies, chemical regimes are changing now and will continue to change in the future. These changing regimes include lower NOx conditions, which change the fate of peroxy radicals (RO2) such that RO2 isomerization and dimerization pathways become more competitive. Additionally, anthropogenic emissions are changing where certain understudied sources (e.g., biofuel-style molecules, personal care products, cooking, and amines) are becoming more important as emissions from mobile sources decline. This session welcomes contributions on advancements of gas and/or multi-phase chemical mechanisms under these or other expected changing regimes including new mechanistic information from experimental, computational, and structure-activity relationship approaches and/or synthesis of chemical information into mechanisms.

Chemical Mechanisms Important at Regional Scales, Across Diverse Regions

Session Chairs: Ilona Riipenen, Stockholm University and Anoop Mahajan, Indian Institute of Tropical Meteorology

A diverse range of complex atmospheric chemistry mechanisms can play an important role on regional scales. Similar chemicals can have very different impacts in different parts of the world. This is due to emissions of different chemicals, different meteorological conditions, and the presence of different kinetic environments on regional scales. This session will showcase some examples of regionally important mechanisms, without which the impacts of atmospheric chemistry would be misrepresented.

Chemistry Heterogeneity Within the Wildfire Smoke Plume

Session Chairs: Georgios Gkatzelis, Forschungszentrum Jülich and Rebecca Buchholz, National Center for Atmospheric Research

Wildfires release significant amounts of pollutants, posing challenges to air quality and public health. This session examines the diverse chemistry within wildfire smoke plumes, exploring factors such as plume rise dynamics, emissions variability (e.g., HONO), and the evolving nature of smoke chemistry from the periphery to the core, where darker chemistry may dominate. We welcome research on the complex interactions between gases and aerosols, aiming to understand the partitioning of key pollutants, the downwind formation of brown carbon and aging processes on aerosols, and the generation of secondary pollutants including ozone and PAN in wildfire-affected regions. Through these discussions, our session seeks to deepen our understanding of wildfire smoke chemistry and its implications for air quality and atmospheric dynamics.

Data-Driven Innovations in Atmospheric Chemistry: From Data to Discovery

Session Chairs: Makoto Kelp, Stanford University and Sam Silva, University of Southern California

Data-driven methods offer the potential to transform research in atmospheric chemistry. With the launch of new geostationary satellites, the deployment of low-cost sensors in previously unmonitored areas, and the measurement of chemical species never before included in regional-global models, we find ourselves in an era where data and scientific progress can outpace our modeling capabilities. This session aims to explore how modeling and algorithmic tools can enhance model predictions, deepen our understanding of atmospheric processes, and effectively use the vast amount of available data. We invite submissions that investigate the application of data-driven methods in atmospheric chemistry, including machine learning, statistical inference, data assimilation, and cloud computing. Contributions may involve the use of low-cost sensors, the integration of data with models, theoretical chemistry, and chamber work.

Fundamental Studies - Basic Processes Shaping the Atmosphere

Session Chairs: Matti Rissanen, University of Helsinki & Tampere University and Rebecca Caravan, Argonne National Laboratory

Atmospheric chemistry can be viewed as a highly complex network of individual chemical reactions that transform gas-phase species into increasingly oxidized molecules. Fundamental studies of the individual reactions in this network, and the overall chemical mechanisms, help to reveal the crucial interconnections and the important reaction pathways responsible for influencing and controlling chemical transformation in Earth’s atmosphere, impacting e.g., oxidant budgets and pollutant formation and removal. In this session, we welcome new findings from fundamental studies that are emerging from both laboratory and theoretical studies.

Instruments and Observations

Session Chairs: Fred Winiberg, NASA Jet Propulsion Laboratory

Instrumentation is fundamental to observing and understanding atmospheric chemistry, both in the field and in the laboratory. We invite presentations focused on current and future instrumentation for the study of gas, particle, and heterogeneous phase species and chemistry. Both in-situ methods (e.g., laser spectroscopy and mass-spectrometry) and remote sensing techniques (e.g., LIDAR and radiometry) will be considered for this session. Presentations focused on the development and characterization of new instrumentation or exciting new observations/laboratory results enabled by unique instrumentation are highly encouraged.

Nighttime Chemistry

Session Chairs: Claudia Mohr, Stockholm University and Carl Percival, NASA Jet Propulsion Laboratory

Night-time chemistry, driven primarily by the nitrate radical (NO3), has been increasingly recognized as being atmospherically important. NO3 plays a key role in controlling the atmospheric burden of non-methane volatile organic compounds (NMVOCs), sulfur-containing compounds, and the aerosol burden, through indirect production of aerosol nitrate and creation of less volatile oxidized organic compounds which can condense and add to secondary organic aerosol (SOA) mass. Nocturnal chemistry has been shown to having increasing importance on the formation of SOA and can shorten the lifetime of NOx. This session will highlight recent advancements in Nocturnal chemistry and its impact on air quality.