Co chairs

• Co chairs: Katerina Sindelarova, Lin Du, Garima Shukla (ECR), Julieta Juncosa (ECR)

The Earth's atmosphere is experiencing profound changes, undergoing complex interactions between the ocean and terrestrial systems. Explaining these interactions is pivotal for predicting future atmospheric changes, climate feedbacks, and environmental impacts. This session invites contributions covering the physical, chemical, and biogeochemical processes involved in atmosphere-ocean-ice-land interactions. Specific topics include air-sea (including snow/ice) exchange of aerosols, gases and oxidants; transport of pollutants and interactions of the atmosphere with biosphere and marine emissions; impacts of land-use/land cover changes and sea-surface state on atmospheric composition and aerosol-cloud interactions; observations and modeling of biomass burning; ocean biogeochemical cycling of nutrients from terrestrial wildfire and mineral dust; novel observational and modeling approaches quantifying interactions and feedbacks. Interdisciplinary studies relevant to SOLAS (Surface Ocean – Lower Atmosphere Study) and iLEAPS (Integrated Land Ecosystem–Atmosphere Processes Study) projects are also welcomed.

Co chairs

• Co chairs: Nicolas Huneeus, Sergey Nizkorodov, Maria Angelaki (ECR), Sachin Kumar Mishra (ECR)

A deep understanding of the fundamental chemical and physical processes in the atmosphere is essential to accurately describe and predict its evolving composition and impacts. This session welcomes contributions that advance our knowledge of key atmospheric processes through curiosity-driven, foundational research. We invite abstracts focusing on the atmospheric chemistry mechanisms governing gas-phase, multiphase, and heterogeneous processes involved in formation and evolution of gaseous and particulate matter constituents. Submissions exploring novel experimental, analytical, theoretical, and numerical approaches—including the development of new chemical mechanisms and process-level modeling—are especially encouraged. The molecular-scale studies of regional and global impacts, emphasizing how small-scale processes shape large-scale changes in the atmosphere, and the submissions that quantify the uncertainties in chemical mechanisms, perform sensitivity analysis, or investigate how key processes respond to evolving environmental conditions, are also welcomed.

Co chairs

• Co chairs: Néstor Rojas, Liya E. Yu, Martin Ramacher (ECR), Flossie Brown (ECR)

This session explores the diverse origins of emissions, from natural processes to anthropogenic activities, and their impacts on health, environmental justice and policy at different temporal and spatial scales. The session covers a wide range of advanced studies, including indoor and urban air pollution, estimation of airborne pollutant emissions, understanding of air quality status and trends, dynamic gas-aerosol transformation in diverse atmospheric environments, and characterization of emerging airborne pollutants (such as per- and polyfluoroalkyl substances (PFASs) and airborne nano-plastics). We welcome studies of far-reaching impacts of air pollution on human health, ecosystems, and climate, alongside strategies for mitigation and adaptation.

Co chairs

• Co chairs: Ruth Doherty, Stuart Piketh, Shahid Uz Zaman (ECR), Cybelli Barbosa (ECR)

Atmospheric composition and air quality are strongly influenced by underlying meteorological conditions which may be modified by climate change. In turn, atmospheric composition affects climate through radiative forcing. Understanding these connections is crucial for both improving air quality and reducing climate impacts. This session will focus on recent research from observational and modelling studies on the interplay between atmospheric composition and weather and climate. We welcome submissions exploring: how weather and climate patterns affect air pollution transport, atmospheric chemistry and air quality; the influence of extreme weather events, such as heatwaves, and short-term climate variability on atmospheric composition and air quality; how future changes in atmospheric composition (including through climate-sensitive emissions) impact air quality and/or climate; and climate and air quality co- benefits.

Co chairs

• Co chairs: Rebecca Garland, Evelyne Touré, Karn Vohra (ECR), William Apondo (ECR)

Advances and diversifying approaches in observational methods, analyses of large data sets (e.g., through AI), and modeling are pushing forward atmospheric chemistry research progress worldwide across various spatial and temporal scales. This session invites contributions showcasing novel strategies in measurement, data integration, and modeling, as well as integrated approaches that provide new methodologies in atmospheric chemistry research. Studies articulating the innovation in these approaches are welcome and could include those leveraging cutting-edge instrumentation, remote sensing platforms, sensor networks, innovative in situ or laboratory methods, new modeling frameworks, and machine learning applications. Studies integrating approaches in an innovative manner are also welcome, as are those that focus on applying techniques in a novel way in data-scarce regions. By highlighting creative, integrated, and next-generation approaches, this session aims to foster discussion on how emerging tools and approaches can deepen our understanding of atmospheric composition, chemistry-climate interactions, and air quality from local to global scale, ultimately informing science-based policy and sustainable solutions.

Panelists/Conveners: Mingjin Tang; Maria Kanakidou, Nikos Mihalopoulos and Sarkawt
Lateef (ECR)