Numerical modeling and prediction of air pollution is complex and uncertain due to a number of factors including numerous non-linear physical and chemical processes involved, characteristic spatial and time scales that span orders of magnitude, incomplete understanding of all involved processes, and uncertain initial and boundary conditions and model parameters (including emissions). Four dimensional data assimilation combines modeling and observation information to improve predictions. In collaboration with colleagues at Texas A&M University and the National Center for Atmospheric Research, I have studied a monte-carlo data assimilation techniques (ensemble-based Kalman filtering) for improving air pollution predictions, numerical models, and observational networks.

• A.L. Stuart, A. Aksoy, F. Zhang, and J. W. Nielsen-Gammon, Ensemble-based data assimilation and targeted observation of chemical tracer in a sea breeze model, Atmospheric Environment, 41: 3082-3094, doi:10.1016/j.atmosenv.2006.11.046, 2007. [view]
  
• F. Zhang, N. Bei, J. W. Nielsen-Gamon, G. Li, R. Zhang, A. Stuart, and A. Aksoy. Impacts of meteorological uncertainties on ozone pollution predictability estimated through meteorological and photochemical ensemble forecasts. Journal of Geophysical Resarch-Atmospheres, 112, D04304, doi: 10.1029/2006JD007429, 2007. [view]
• A.L. Stuart, A. Aksoy, J. W. Nielsen-Gammon, F. Zhang. Ensemble Kalman filter data assimilation for improved chemical tracer forecasts in a 2-D sea breeze model. The 86th American Meteorological Society Annual Meeting, January, 2006.
• A.L. Stuart, A. Aksoy, F. Zhang, J. W. Nielsen-Gammon,. Data assimilation and targeted observation of chemical tracer concentrations in a sea breeze model forecast using an ensemble Kalman filter. Eos Trans. AGU, 86(52), Fall Meet. Suppl. Abstract A33F-04, December, 2005. [view]

Air pollution is an important environmental exposure with significant adverse human health effects. We study exposures of populations to air pollutants, focusing on improving estimates of spatial distributions of air quality and investigating effects on disadvantaged populations.

• A.L. Stuart, M. Zeager, N. Poor, S. Mudhasakul, W. Sriwatanapongse. Assessing environmental equity related to local air pollution in Tampa, FL. Extended Abstract for the Air & Waste Management Association Annual Conference and Exhibition, 2008.[view]
• M. Zeager, A.L. Stuart*. Nitrogen Dioxide Measurements in Neighborhoods in Hillsborough County. Abstract, USF Health Research Day. February, 2008.
• A.L. Stuart. Localized air pollution and environmental equity in Tampa, Florida. Abstract and Oral Presentation. AEESP Research and Education Conference, Blacksburg, Va., July, 2007.
• S. Mudhasakul, W. Sriwatanapongse, and A.L. Stuart*. Localized air quality and population disparities in Tampa, FL., EOH Public Health Seminar, USF, March 2007.
• A.L. Stuart, C. Braithwaite, F. Breckner. Investigation of health disparities due to localized air pollution exposures in Tampa, FL, American Public Health Association Annual Meeting, November, 2006. [view]
• F.B. Breckner and A.L. Stuart*, Health implications of diesel vehicle emissions in Jakarta. FL A&WMA 42nd Annual Conference, November, 2005.
• S. Hayes, A. Stuart, S. Pye, L. Levin, J. Killus, Assessing exposure to airborne particulate matter,  Proceedings of the 89th Annual Meeting of the Air and Waste Management Association.  June 1996.

Mercury contamination is an important global environmental problem that has led to very visible community health impacts. Although the detrimental effects of high mercury exposures have long been known, there remain many unknowns concerning the factors that lead to continued exposures. These include lack of adequate knowledge of its cycling in the environment and of the social (economical, political, and cultural) issues that affect its continued use, release, and consumption. In collaboration with colleagues Dr. Maya Trotz (CEE) and Dr. Fenda Akiwumi (Geography), we study the factors affecting mercury use, cycling, and exposures from a full system perspective.

• A.L. Stuart, M. Trotz, F. Akiwumi. An integrated student-centered study of mercury in the economy, society, and environment of the Tampa Bay area. Abstract (accepted), American Public Health Association Annual Meeting, 2008.
• T. Halfhide, J. Howard, R. Michael, C. Einmo, D. Dey, M. Trotz, F. Akiwumi, and A.L. Stuart*. Understanding mercury in Hillsborough River, Florida, using Sustainability Concepts. Abstract and Poster. USF Going Green Expo, April, 2008. (Poster won first prize in the student poster competition.)
• R. Michael, A.L. Stuart*, J. Howard, M. Trotz, N. Caesar, F. Akiwumi. Modeling of the environmental, economic, and socio-cultural dynamics of mercury. Abstract, USF Health Research Day. February, 2008.
• P. Borisuth, W. Sriwatanapongse, and A.L. Stuart*. Mercury atmospheric deposition study for Tampa Bay. Student Poster Session, AEESP Distinguished Lecture, University of Central Florida, March 2007.

Emergency releases of toxic chemicals and biological agents pose a significant hazard to human health. The extent of the potential hazard is affected by the physical, chemical, and biological processes involved in release, transport, and transformation of toxic species in the atmosphere. We have used modeling methods to investigate these processes, to understand their impact on the resultant hazards, and to explore mitigation strategies.

• D. Martin and A.L. Stuart*. Aerosolized microorganisms: survivability, infectivity detection and modeling: A literature review. FL A&WMA 43rd Annual Conference, October, 2006.
• Environmental Science & Technology, 39(8): 2736 - 2743, doi:10.1021/es048705e, 2005. [view]
• A.L. Stuart and D.A. Wilkening. Degradation of biological weapons agents in the environment and its implications for terrorism response. 6th Annual Meeting of the Consortium on Biodefense Researchers. June, 2005. [view]
• Chyba, C, M.F. Cuellar, L. Donohue, L. Eden, M. Lynn, M. May, E. Pate-Cornell, J. Pullen, T. Putnam, M. Race, and A. Stuart. Final Report: Top Officials 2 Full Scale Exercise. Center for International Security and Cooperation, Stanford University. June 2003.
• Crites, T, T. Putnam, F. Steinhausler, and A. Stuart. Report of the delegation from the Center for International Security and Cooperation (CISAC): TOPOFF-2 Planning Meeting for RDD Attack. Stanford University. October 2002.
• A.L. Stuart, S. Jain, and S.B. Libicki, The use of long-term meteorological information to predict impact probabilities resulting from toxic chemical releases.  Proceedings of the International Topical Meeting of Probabilistic Safety Assessment.  American Nuclear Society.  October 1996.

Cloud ice chemistry and microphysics:

Cloud systems containing ice have significant impacts on acid precipitation, air pollution, and climate change. Although many cloud-chemical processes have received extensive study, interactions of chemicals with the ice-phase are poorly understood. Our work has investigated chemical partitioning during freezing and riming of supercooled drops, in collaboration with colleagues at the National Center for Atmospheric Research.

• R. Michael, A.L. Stuart*, Investigation of the factors influencing volatile chemical fate during steady-state accretion on wet-growing hail. Abstract and Poster. Eos Trans. AGU, Fall Meet. Suppl. Abstract A53B-1156, Dec. 2007.
• R. Michael, A.L. Stuart*. Chemical fate during hail growth. College of Engineering Scholarship Day, USF, April 5, 2007.
• R. Michael, A.L. Stuart*, Investigation of the factors affecting chemical fate during ice accretion in the wet-growth regime. Abstract and Poster. FL A&WMA 44th Annual Conference, October, 2007.
• M.C. Barth, S.-W. Kim, W.C. Skamarock, A.L. Stuart, K.E. Pickering, and L.E. Ott. Simulations of the redistribution of formaldehyde, formic acid, and peroxides in the 10 July, 1996 Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone deep convection storm, Journal of Geophysical Research, 112, D13310, doi:10.1029/2006JD008046, 2007. [view]
• A.L. Stuart and M.Z. Jacobson. A numerical model of chemical partitioning during cloud drop freezing. Journal of Atmospheric Chemistry, 53: 13-42, doi:10.1007/s10874-006-0948-0, 2006. [view]
• A.L. Stuart and M.Z. Jacobson. Drop-scale numerical modeling of chemical partitioning during cloud hydrometeor freezing. Proceedings of the 14th International Conference on Clouds and Precipitation. International Association of Meteorology and Atmospheric Sciences. July 2004. [view]
• A.L. Stuart and M.Z. Jacobson. Chemical retention during dry-growth riming. Journal of Geophysical Research, 109, D07305, doi:10.1029/2003JD004197, 2004. [view]
• A.L. Stuart and M.Z. Jacobson. A timescale investigation of volatile chemical retention during hydrometeor freezing: Non-rime freezing and dry-growth riming without spreading. Journal of Geophysical Research, 108(D6), 4178, doi:10.1029/2001JD001408, 2003. [view]
• A.L. Stuart and M.Z. Jacobson. A theoretical and modeling study of volatile chemical partitioning during cloud hydrometeor freezing. Eos. Trans. AGU, 84(46). Fall Meet. Suppl., Abstract A12F-04. 2003. [view]
• A.L. Stuart. Volatile chemical partitioning during cloud hydrometeor freezing and its effects on tropospheric chemical distributions. Ph.D. Thesis, Stanford University. Stanford, California. September 2002. [view]
• M.C. Barth, A.L. Stuart, and W.C. Skamarock. Numerical simulation of the July 10 Stratospheric-Tropospheric Experiment: Radiation, Aerosols, and Ozone (STERAO) - Deep Convection experiment storm: Redistribution of soluble tracers. Journal of Geophysical Research. 106(D12): 12,381-12,400. June 27, 2001. [view]
• A.L. Stuart, M.Z. Jacobson, M.C. Barth, and W.C. Skamarock. Volatile chemical retention during hydrometeor freezing and its effects on tropospheric chemistry. Atmospheric Sciences Symposium. University of California at Berkeley. November 2001.
• A.L. Stuart, M.Z. Jacobson, M.C. Barth, and W.C. Skamarock. Chemical transfer to ice-containing cumulonimbus cloud hydrometeors and its effects on tropospheric chemical distributions. Millennium Symposium on Atmospheric Chemistry. American Meteorological Society. January 2001.
• A.L. Stuart and M.Z. Jacobson, Interactions between chemicals and ice-containing convective cloud hydrometeors and their effects on tropospheric chemical distributions. U.S. EPA STAR Fellowship Conference, Washington D.C., August 2001.
• A.L. Stuart, M.C. Barth, W.C. Skamarock, And M.Z. Jacobson. A three-dimensional modeling study of the effects of solid-phase hydrometeor-chemical interaction in cumulonimbus clouds on tropospheric chemical distributions. Proceedings of the 13th International Conference on Clouds and Precipitation. International Association of Meteorology and Atmospheric Sciences. pp. 932-935. August 2000. [view]
• M.C. Barth, A.L. Stuart, and W.C. Skamarock. The influence of cloud processes on the distribution of chemical species for the 10 July 1996 STERAO/Deep Convection storm. Proceedings of the 13th International Conference on Clouds and Precipitation. International Association of Meteorology and Atmospheric Sciences. pp. 960-963. August 2000. [view]
• A.L. Stuart, M.Z. Jacobson, M.C. Barth, and W.C. Skamarock. Effects of solid-phase cloud hydrometeors in convective clouds on chemical distributions and deposition. U.S. EPA STAR Fellowship Conference, Washington D.C., July 2000.
• A.L. Stuart, M.C. Barth, W.C. Skamarock, And M.Z. Jacobson. Solid microphysics and chemistry interactions in thunderstorm simulation using a three-dimensional cloud model. Eos Supplement, Transactions. American Geophysical Union Fall Meeting. 1998.
• Eos Supplement, Transactions. American Geophysical Union Fall Meeting. 1997.

• Ryan Michael, EOH PhD student, Systems modeling for mercury cycling and exposures
• Chris Einmo, CEE ME / EOH MSPH student, CMAQ modeling of air quality in Tampa
• Joe Graham, EOH MPH / CEE ME student, Passive aldehydes sampling and analysis
• Ryan Davis, EOH MPH / Anthro MA student GA, literature collection of elemental source profile data
• Watcharaphol Traisantikul, KMUTT ChE MS student, CALPUFF modeling of air quality in Tampa
• Tippawan Dethtada, KMUTT ChE MS student, urban growth modeling for air quality application
• Somkit Bunchitomongkhon, KMUTT ChE MS student, mass balance calculations for mercury cycling
• Alex Tapper, undergraduate honors student, dental facilities and mercury

• Ryan Michael, CEE MSES 2008 (Master's thesis), Fate of volatile chemicals during wet-growth riming in clouds
• Michelle Zeager, EOH MPH 2008 (Special Project), Passive sampling of NO2 levels and air quality equity in Tampa
• Brett Galbraith, CEE ME 2007 (GA), Temporal trends in mercury emissions in Florida
• Sarntharm Mudhasakul,ChE MS 2007 KMUTT (Master's thesis), Air quality and environmental equity
• Pakornkit Borrisuth, ChE MS 2007 KMUTT (Master's thesis), Mercury deposition to Tampa area
• Chantal Braithwaite, BS 2006 (Undergraduate Honors Thesis), Air quality health disparities in Tampa
• Fritz Breckner, EOH MPH 2006 (GA), Vehicular emissions and air quality in Jakarta
• Tanmaykumar Patel, EPI MPH 2006 (GA), Biostatistical analysis of air quality and respiratory and cardiovascular health
• Stacia Perry-Eaton, 2006 (RET Teacher), Air quality mapping and monitoring regulations analysis