The Paris 2024 Olympic Games will not only be a spectacle of athletic prowess, but also a hub for cutting-edge meteorological research. This ambitious research demonstration project brings together meteorological services and universities from around the world, including France, Austria, Australia, Canada, China, Sweden, the United Kingdom, and the United States. This project, endorsed by the World Meteorological Organization’s World Weather Research Program and Global Atmospheric Watch Urban Research Meteorology and Environment project, aims to revolutionize weather forecasting in urban areas.
Forecasting for the Games: A Crucial Task
Weather is a critical factor in the success of any major sporting event, especially the Olympics. Accurate and reliable forecasts of temperature, humidity, visibility, and wind extremes are essential for event scheduling, athletic performance, and course conditions. Moreover, these forecasts ensure the safety of athletes, support staff, spectators, and transit operations.
The Focus: Weather in Urban Environments
The research project is being run in parallel with Meteo-France’s regular forecast and meteorological services for the duration of the Olympic Games. It encompasses all the Olympic sites, both in Paris and the coastal areas of Marseille, to further meteorological research on the “future Weather Forecasting systems at 100m (or finer) resolution for urban areas.” The project will particularly focus on extreme events in summer cities, such as thunderstorms and urban heat islands, and their consequences.
The Challenges of Urban Meteorology
Dense urban areas, characterized by high-rise buildings and concrete infrastructure, pose challenges for high-resolution numerical weather prediction. They also face numerous environmental risks due to air pollution, weather hazards, and climate change. With about 3.5 billion people living in urban areas, a figure that is continuously increasing, the need for accurate urban meteorology is more crucial than ever. Urban meteorology encompasses not only simple weather observations and forecasts but also environmental parameters like temperature, aerosol concentration, and precipitation.
Building on Previous Research
While past Olympic research projects in Sydney (2000) and Beijing (2008) focused on nowcasting (forecasts for the minutes and hours ahead) and the predictability of thunderstorms, they did not utilize models at resolutions tailored for dense urban areas. Since then, significant advancements have been made in urban meteorology. For example, the recent Tokyo Metropolitan Area Convection Study for Extreme Weather Resilient Cities investigated extreme storm events using radars and other instruments.
The Paris 2024 Research Project: A Multi-pronged Approach
The Paris 2024 Olympics research demonstration project is structured around five key scientific questions:
- Nowcasting & Numerical Weather Prediction in cities at about 100m of resolution
- High-resolution thunderstorm nowcasting (probabilistic and deterministic) in the urban environment, Urban heat islands and cool areas, air quality, in cities
- Nowcasting and forecast in coastal cities (for the Marseilles site)
- Big data, non-conventional data, and their uses
- How to deliver tailored weather, climate, environmental information at infra-urban resolution?
Numerical Weather Prediction at Unprecedented Resolution
Numerical Weather Prediction (NWP) at 100m horizontal scales is crucial for accurately capturing small-scale atmospheric processes and features. At this scale, NWP models can better simulate the complex interactions between the atmosphere and the Earth’s surface, including urban areas, complex terrain, coastlines, and land-water interfaces. These interactions are vital for predicting small-scale weather events, such as thunderstorms, fog, urban heat islands, sea breezes, and mountain-induced precipitation.
Three Core Focus Areas
The project features three primary focus areas:
1. Air Quality Group
Air pollution is a major concern in urban areas, where concentrations of pollutants like nitrogen oxides and particulate matter are particularly high and spatially heterogeneous. Detailed modeling is necessary to estimate the health impacts of these concentrations. Chemistry and transport models are often used to simulate and predict background concentrations on a regional scale. However, these models cannot account for the local variations in concentrations.
As part of the Paris Olympics research project, two intercomparison exercises have been set up. The first concerns regional concentrations during summer heat episodes, when ozone concentrations are high. The second concerns local urban concentrations.
2. High-Resolution Modeling (Intercomparison)
Nearly real-time forecasts will be produced by seven different centers, with seven models operating at a hectometric (100m horizontal) resolution. These models will be analyzed in daily meetings during the Olympics and Paralympics, both in a pure forecast point of view and retrospectively, comparing them to observations. These meetings will identify the advantages and limitations of hectometric models for forecasting compared to well-known kilometric and global scale models.
3. Social Science Study
This study aims to strengthen the understanding of forecasts for large sporting events, with the objective of comprehending how forecasters formulate their advice to decision-makers. It will interact with the “Heat and Health in Cities” project, which characterizes the hazards associated with heat exposure, its impacts on morbidity and mortality, and the provision of information to stakeholders.
Conclusion
The Paris 2024 Olympics research demonstration project represents a significant leap forward in urban meteorology. By bringing together international expertise and cutting-edge technology, the project will revolutionize weather forecasting in urban areas, ensuring the safety and success of the Olympic Games while also advancing scientific understanding of the complex interplay between weather, climate, and urban environments. The research will also have broader implications for cities worldwide, contributing to the development of more resilient and sustainable urban futures.
