Cities and urban environments are a key aspect of the United Nations (UN) Agenda for Sustainable Development, and include scientific and socio-economic perspectives. As urbanisation processes continue across the world, its representation and understanding needs to be further improved to fully assess its impact on weather, air quality, water quality, energy consumption/production and climate. These aspects are crucial both for advancing current knowledge and creating effective sustainable solutions. Key challenges in accomplishing this task vary according to the level of complexity and multi-scale dimension of diverse urban environments.

This session welcomes modelling and observational studies that aim to investigate different aspects of urbanization (e.g. urban heat island, air quality, vulnerability to extreme events, urban/peri-urban agriculture) and its feedback on weather and climate systems, with a particular focus on application for sustainable adaptation plans. Novel methods that aim to assess urban representation and/or to bridge the different scales of the diversity of topologies are encouraged. The impact of cities on weather, air quality, climate and/or their extremes (e.g. drought, precipitation, air pollution episodes), as well as on climate change and on population and adaptation will also be discussed in this session.

Topics may include:
• New urban parameterizations, methods to derive urban parameters for numerical models.
• Implementation of climate mitigations, adaptation strategies (e.g. blue-green infrastructures) and self-government policies in cities and urban context.
• Impact of the different urban parameterizations on the atmospheric dynamics at different scales.
• Impact of the urbanization including estate and industrial on weather and/or climate extremes.
• Field measurements of urban climate, e.g. precipitation, CO2 concentrations and flux, boundary layer characteristics.
• Population vulnerability to urban climate and climate change.
• Extreme events' (e.g. drought, rainfall events, heat wave) impacts on urban areas.
• Urban emissions of climate forcers, air pollutants and anthropogenic heat.
• Urban air quality and meteorological interactions.
• Meteorology or air pollution modelling of all scales with focus on urban areas.
• Coupling and downscaling of global, regional and urban scale modelling approaches to quantify climate and atmospheric composition impacts and feedbacks.
• Integrated monitoring, modelling and forecast systems for urban hazards.
• Urban transition to cleaner fuels and their meteorological or AQ impacts.
• Crowd sourced data/novel data sources in cities
• Successes, challenges and limits of AI approaches for urban research
• Assimilation of 4D data and machine learning applied for air quality simulation
• Social science analyses of cities

Organised jointly with:
World Meteorological Organization (WMO) Global Atmospheric Watch Project GAW Urban Research in Meteorology and Environment (GURME)
WMO World Weather Research Programme (WWRP)