Chairs: Christine Wiedinmyer, Kim Oanh N.T.

Urbanization compounded by a soaring increase in energy consumption in the expanding urban population has caused impacts on the atmospheric chemistry. In particular, the demand in urban transportation has caused a rapid growth of traffic fleets, especially in the developing countries, which result in high levels of air pollution emissions in urban areas. Infrastructure development and the high emission of air pollutants from various sources in urban areas and surrounding rural areas change the chemical and physical processes in the urban atmosphere. This session aims to address these changes. Specifically the session will include anthropogenic and biogenic emission sources in urban and surrounding rural areas, urban/regional scale air quality studies addressing the urban air pollution in interaction with rural areas, indoor air quality and modeling, exposure and health effects, megacity chemistry and the impact of megacities on regional and global environments.

Chairs: Jennifer Murphy, Amos Tai

Ecosystems, including agroecosystems, play a key role in shaping atmospheric composition through various physical and biogeochemical pathways. The productivity of vegetation and crops is, on the other hand, strongly influenced by the changing chemistry of the atmosphere as a result of air pollution and climate change, with ramifications for social and economic systems. This session will be devoted to observational and modeling research on the interactions between ecosystems, agriculture and atmospheric chemistry. Topics may include but not limited to: impacts of land use and ecosystem changes on air quality, including deforestation, biomass burning, biofuel production, etc.; impacts of agricultural emissions and food production on air quality; impacts of air pollution on natural vegetation and agriculture; and feedbacks within the atmosphere-biosphere system.

Chairs: Claire Granier, Gabrielle Petron

Global energy consumption has almost doubled since the early 1980s. Non renewable energy sources represented 81% of the world energy consumption in 2013. For the past decades, energy systems have had a large impact on the atmosphere composition and properties. From production (conventional oil, gas and coal as well as shale gas and biofuel) to end use (commercial/ residential/industries, ground/ship/air transportation), the session will discuss local, regional and global impacts of past, current and projected energy related activities on atmospheric chemistry and climate. The impact of growth of energy-related activities in the Arctic will also be considered.

Chairs: Noureddine Yassa, Andrew Rickard

Fundamental studies of the composition and chemistry of the atmosphere, in the laboratory or in the field in conjunction with satellite data and computer models, are of key importance to understanding the complex interactions between the atmosphere and living organisms and ecosystems. This session will include wide ranging research on the chemical kinetics of the gaseous and aerosol phases, photochemical mechanisms, multiphase processes, gas/particle interactions and aerosol nucleation, chamber experiments, theoretical and computational chemistry, measurement technique development, health impacts and connections to observations.

Chairs: Hiroshi Tanimoto, Terry Keating

Driven largely by global economic development, atmospheric chemistry and climate together control the variability and distributions of trace gases and aerosols, with significant implications for society and ecosystems. Our understanding of these conjoined processes is informed by a suite of in situ and satellite observations, regional to global scale atmospheric models, and updated emissions inventories. This session will discuss our efforts to better understand these processes at the regional to global scale, including studies of global trends in emissions and atmospheric composition, regional to global scale transport of air pollutants, linkages and feedbacks between atmospheric chemistry and climate processes, and their global impacts on human health, ecosystems, and society.

Chairs: Jim Crawford, Michel Grutter

Continued expansion of atmospheric composition observations are needed to develop a deeper understanding of chemical and physical processes as well as secular change. Observations of short and long-term variability and trends of atmospheric composition are possible for an increasing number of constituents from multiple perspectives, including ground, aircraft, balloon, and satellite platforms. This session includes field observations spanning all scales and their interpretation through analysis and modeling. Additionally, contributions from technological developments of new methodologies and analytical algorithms to retrieve air pollutants, greenhouse gases and the chemical and physical composition of aerosols are welcome, as well as new findings from existing satellites and advances in upcoming satellite missions devoted to investigating the spatial and temporal variability of atmospheric constituents.