ARB Research Seminar

This page updated June 19, 2013

Advanced Receptor Modeling for Source Identification and Apportionment

Philip K. Hopke, Ph.D., The Bayard D. Clarkson Distinguished Professor, Department of Chemical Engineering, Clarkson University, Potsdam, New York

March 20, 2002
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA



Over the past several years, there have been new approaches to receptor modeling including advanced factor analysis (UNMIX and PMF) and application of trajectory ensemble methods (PSCF and RTA). In this presentation, the background to the receptor-modeling problem will be presented. The factor analysis approach, Positive Matrix Factorization (PMF) that uses an explicit least-squares formalism will be described. This method then permits better treatment of the errors in the data, below-detection-limit and missing values, and permits easier imposition of constraints. In this seminar, PMF will be illustrated with its application to data from Underhill, Vermont. The factors provide an idea of the types of sources that can be identified but does not provide any spatial information on where the likely sources are located. The use of Potential Source Contribution Function (PSCF) analysis will be outlined and again applied to the data from Underhill, Vermont. Finally, new ways to expand the factor analysis model will be presented along with its application to simulated data created several years ago by the Environmental Protection Agency will be described.

Speaker Biography

Dr. Philip K. Hopke is the Bayard D. Clarkson Distinguished Professor in the Departments of Chemical Engineering and Chemistry at Clarkson University in Potsdam, New York. Dr. Hopke has been involved in sampling, analysis, and interpretation of data on airborne particulate matter for over 30 years. He has been a leader in the development of multivariate data analysis methods for source identification and apportionment. He is currently the Chair of the Environmental Protection Agency's Clean Air Scientific Advisory Committee and its Subcommittee on Particulate Matter Monitoring. Professor Hopke is also a member of the National Research Council's Committee on Research Priorities for Airborne Particulate Matter and the NRC Committee on Air Quality Management in the United States. He received his BS in Chemistry from Trinity College, Hartford, Connecticut and his MS and Ph.D. in Chemistry from Princeton University. He was a post-doctoral associate at M.I.T. and has held faculty positions at SUNY-Fredonia and the University of Illinois at Urbana-Champaign before joining Clarkson University in 1989. He has published over 275 papers, has written one book and edited five others. He is currently a visiting professor in chemical engineering at the University of California at Los Angeles.

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