The USEPA has embarked on the Advanced Air Quality Model System (AAQMS) project to enable modeling of air quality from global to regional to local scales. The system will have three configurations: 1. Global meteorology with seamless mesh refinement and online (coupled) atmospheric chemistry; 2. Regional (limited area) online meteorology and chemistry; and 3. Offline (sequential) regional meteorology and chemistry. A team of scientists in the Atmospheric & Environmental Systems Modeling Division in the Office of Research and Development is developing a global online configuration which includes the Model for Prediction Across Scales – Atmosphere (MPAS-A), developed at the National Center for Atmospheric Research (NCAR), coupled with the latest version of the Community Multiscale Air Quality (CMAQv5.3) model developed at the U.S. EPA. This multiyear development and evaluation effort offer many opportunities for postgraduate fellows to learn new skills and gain valuable research experience collaborating with a team of experienced atmospheric modeling scientists.  

The objective of this research opportunity is to advance air quality modeling in any of several areas of meteorological, chemical, and physical process modeling, or in advancing numerical and computational modeling techniques for the next generation system. Possible research topics in the AAQMS project include:

Atmosphere-surface interactions: Coupled meteorology and air quality model systems require comprehensive land models that include numerical simulation of many biosphere processes including vegetation evapotranspiration and seasonal variations of growth, leaf area and soil moisture in multiple layers. Both meteorology and air quality depend on many air-surface processes. For meteorology key processes include surface fluxes of heat, moisture, and momentum. Air quality modeling requires realistic simulation of dry deposition of gasses and aerosols as well as emissions of biogenic VOCs, windblown dust, and seasalt. Some air quality species such as ammonia exhibit bi-directional flux behavior. At the EPA we have developed the PX-LSM that is used in WRF and MPAS and dry deposition model used in CMAQ. We also developed a bi-directional ammonia flux model that involves coupling of EPIC-WRF-CMAQ. All of these process model components should be further developed for global application in the MPAS-CMAQ system.

Another focus could be on application of a variety of satellite data for assimilation and evaluation. For example, vertical column concentrations of NO2 and Formaldehyde from TROPOMI and the upcoming TEMPO satellites can be used for evaluation of the model simulations and potentially for adjustment of emissions particularly in parts of the world where bottom-up emission inventories are not well developed. Also, the coupled global meteorology-air quality model would benefit the incorporation of advanced high-resolution earth surface characterization data such as land-use, vegetation types, LAI, coverage, and soil related parameters such as texture and soil moisture. Air quality model evaluation over the entire globe using remote and in-situ measurements of gaseous and particulate air pollutants is an important area of research

 

References

Skamarock WC, Klemp JB, Duda MG, Fowler LD, Park S, Ringler TD: A Multiscale Nonhydrostatic Atmospheric Model Using Centroidal Voronoi Tesselations and C-Grid Staggering. Monthly Weather Review 140: 3090-3105, 2012. https://doi.org/10. 175/MWR-D-11-00215.1

Pleim, J., D. Wong, R. Gilliam, J. Herwehe, R. Bullock, C. Hogrefe, G. Pouliot, L. Ran, B. Murphy, D. Kang, W. Appel, R. Mathur, and E. Hubal, Hubal, The New Generation of Air Quality Modeling Systems. Environmental Manager, October 2018.

Gilliam, R. C., Herwehe, J. A., Bullock, Jr, O. R., Pleim, J. E., Ran, L., Campbell, P. C., & Foroutan, H. (2021). Establishing the suitability of the model for prediction across scales for global retrospective air quality modeling. Journal of Geophysical Research: Atmospheres, 126, e2020JD033588. https://doi.org/10.1029/2020JD033588

 

Keywords:

Air quality modeling; Cloud processes; Atmosphere-biosphere interactions; Atmospheric chemistry; CMAQ; MPAS;

Citizenship:  Open to U.S. citizens and permanent residents

Level:  Open to Postdoctoral and Senior applicants