Abstract: Regional to urban scale atmospheric models for integrated modeling criteria air pollutants (CAPs) (e.g., SO2, NO2, O3, CO, and PM) and greenhouse gases (GHGs) (e.g., CO2 and CH4) provide a powerful tool for the development of synergetic strategies and interventions to mitigate air pollution and climate change. Such integrated models, however, are lacking, due mainly to a historic separation of CAPs and GHGs modeling, few GHGs emissions datasets, and limited understanding of CAPs- GHGs interactions and their feedbacks into weather and climate system. In this work, an innovative integrated model system is developed to bridge the gaps based on Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) and the WRF Greenhouse Gas Model (WRF-GHG) (referred to as WRF-Chem-GHG). WRF-Chem-GHG can simultaneously simulate the atmospheric evolution of CAPs and GHGs and their interactions via meteorology, radiation, cloud, and chemistry. Multi-year and multi-scale simulations are performed using WRF-GHG and WRF-Chem-GHG over contiguous U.S. (36-km), northeastern U.S. (6-km), and Greater Boston (1-km). The results are evaluated using observations from the U.S. NOAA’s Meteorological Aerodrome Report (METAR) network for meteorology, the U.S. EPA’s surface networks for CAPs such as (e.g., the Aerometric Information Retrieval Now (AirNow) and the Aerometric Information Retrieval System– Air Quality System (AIRS-AQS)), and the tall towers datasets for CO2 from the NOAA’s Carbon Cycle Greenhouse Gases (CCGG) program. WRF-Chem-GHG’s ability in simulating both CAPs and GHGs, and their interactions in a changing climate is demonstrated.

Keywords: Intergrated modeling, criteria air pollutants, greenhouse gases, multi-scale, climate change