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Atmospheric Modeling and Analysis Research

Research in Action

Air Quality Model Evaluation International Initiative (AQMEII)


Regional air quality modeling has undergone considerable development during the last three decades worldwide because of increased concern regarding the impact of air pollution on human health and ecosystems. Numerous air quality models have been developed by research groups in North America and Europe and are being widely used for designing emission control policies and forecasting air quality. However, unlike other geophysical sciences such as climatology, there has never been a coordinated international effort by American and European research groups to study and assess air quality model performance.


EPA atmospheric modeling scientists are co-leading an international research collaboration with the goal of building a common strategy for regional and global model development and evaluation. The Air Quality Model Evaluation International Initiative (AQMEII) is a joint project with the European Commission Joint Research Centre based in Brussels, Belgium. Participants include air quality modelers, atmospheric chemists, and meteorologists from the United States, Canada, Denmark, France, Finland, Greece, Germany, Norway and the Netherlands. Scientists involved in the initiative are working to answer the following questions:

  • Can current versions of coupled meteorology and air chemistry models developed in North America and Europe accurately simulate feedbacks between aerosol and radiation?
  • How important is interaction between regional and global-scale processes in air quality and climate change studies?
  • Are air quality/climate change interactions simulated by global models comparable to interactions simulated by regional models?
  • Can global models learn from regional-scale models and vice versa?

Scientists involved in the initiative are attempting to find ways to validate the many different models used to estimate air quality at local levels around the world. They are also looking at how these models might be used together, how lessons learned on the regional scale can help scientists involved in developing global-scale air quality models, and whether these models can be used to predict ways that climate change will affect air quality.

Results and Impacts

During Phase 1 of the initiative, scientists compared the performance and results of many models, and found a significant amount of variation in their predictions. Their research demonstrated how biases from different meteorological fields can affect ways models predict pollutant concentrations.

A database containing all observations and corresponding outputs from the Phase 1 modeling systems is available to the scientific community for developing and applying model evaluations.

Planning for the second phase of the initiative is underway. Phase 2 will involve conducting annual simulations for 2006 and 2010 using several coupled regional-scale models over North America and Europe. Scientists plan to use these findings to build more comprehensive and global air quality models that can help answer questions about relationships between air quality and climate change.

Related Publications
  • Alapaty, K. et al., 2012.  New Directions: Understanding interactions of air quality and climate change at regional scales, Atmospheric Environment, 49, 419-421

  • Galmarini, S., and Rao, S.T., 2011.The AQMEII two-continent regional air quality model evaluation study: fueling ideas with unprecedented data, Atmospheric Environment, 45, 2464.

  • Rao, S.T., Galmarini, S., Puckett, K., 2011. Air quality model evaluation international initiative (AQMEII). Bulletin of the American Meteorological Society 92, 23-30.

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