Advancing the Community Multiscale Air Quality (CMAQ) model's air-surface exchange involves the development of new algorithms, either replacing older science or incorporating new science, and the refinement of current algorithms to maintain them at the state of the science.

Research Projects

• Bi-Directional air surface exchange (mercury, ammonia, and nitrogen oxide)
• Unidirectional air-surface exchange
  Using data from recent field studies, EPA is working to improve in CMAQ the characterization of the processes that control the unidirectional exchange of pollutants between the atmosphere and Earth’s surface. 
• Mosaic
  Traditional CMAQ output contains deposition estimates based on average characteristics of a grid cell.  Since dry deposition varies with the underlying land surface, ecological applications often require more detailed estimates.  EPA's atmospheric modeling researchs have recently added the capability to CMAQ to calculate and output hourly land-use specific deposition values.
• Cloud deposition
  Sensitive ecosystems in high elevation areas are often impacted by deposition from clouds that impinge on the terrain.  Future CMAQ development will target this missing pathway from the total deposition budget.
• Agroecosytem modeling with the Economic Policy Integrated Climate (EPIC) capabilities including emissions
  The EPIC farm management and biogeochemical process model is being linked with the Community Multi-Scale Air Quality Model (CMAQ) to explore sustainability (environmental, economic and social) issues associated with the pollutantants ammonia, nitrous oxide, and nitric acid.. 
• Land use change capability including advanced LAI
  Natural and anthropogenic land use change effects ecosystem structure (for intance leaf area) and function (such as emissions) which, in turn, affects air quality.  New models and data sources will  improve the temporal and spatial characterization of these changes