Grantee Research Project Results

Mathematical Models of the Transport and Fate of Airborne Organics

EPA Grant Number: R824970C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R824970
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: HSRC (1989) - Northeast HSRC
Center Director: Sidhu, Sukh S.
Title: Mathematical Models of the Transport and Fate of Airborne Organics
Investigators: McRae, Gregory J.
Institution: Massachusetts Institute of Technology
EPA Project Officer: Hahn, Intaek
Project Period: January 1, 1992 through June 30, 1997
Project Amount: Refer to main center abstract for funding details.
RFA: Center on Airborne Organics (1993) Recipients Lists
Research Category: Targeted Research

Objective:

The goal of this research is to develop a new mathematical and computational framework for the systematic sensitivity and uncertainty analysis of the complex transport and transformation processes that control the concentration dynamics of airborne organics. A particular focus is the implementation of numerical procedures that are much more computationally efficient than even the best Monte Carlo sampling strategies. Once the tools have been developed, the approach is to carry out a detailed investigation of the photochemical oxidation mechanisms for airborne organics.

Approach:

In this research a new approach termed the Deterministically Equivalent Modeling Method (DEMM) has been developed. Uncertain parameters are treated as random variables that are in turn approximated using orthogonal basis function expansions in the probability space. For example, if the uncertain inputs are independent and Gaussian-distributed, the expansion is based on standard Hermite polynomials. A complete description of the method is contained in Tatang (1994).

Rationale:

One of the consequences of using models to describe the formation and transport of photochemical air pollution is that some approximations are involved. In addition there are also measurement errors in the data used to develop inputs and kinetic parameters for the reaction mechanisms. The key issue is not that uncertainties are involved, they will always be present, but to identify which of the inputs contributes most to the uncertainty in predictions. The present set of tools available to the research community are simply computationally intractable for the complex reaction schemes needed to describe the photochemistry of airborne organics.

Supplemental Keywords:

mathematics, organics, model, air., RFA, Scientific Discipline, Air, Waste, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Mathematics, Environmental Chemistry, Fate & Transport, Atmospheric Sciences, particulates, fate and transport, mathematical model, air quality models, ambient measurement methods, airborne organics, atmospheric transformation, air pollution, deterministically equivalent modeling method, atmospheric transport, particle transport

Progress and Final Reports:

Main Center Abstract and Reports:

R824970 HSRC (1989) - Northeast HSRC

Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R824970C001 Chemical Kinetic Modeling of Formation of Products of Incomplete Combustion from Spark-ignition Engines
R824970C002 Combustion Chamber Deposit Effects on Engine Hydrocarbon Emissions
R824970C003 Atmospheric Transformation of Volatile Organic Compounds: Gas-Phase Photooxidation and Gas-to-Particle Conversion
R824970C004 Mathematical Models of the Transport and Fate of Airborne Organics
R824970C005 Elementary Reaction Mechanism and Pathways for Atmospheric Reactions of Aromatics - Benzene and Toluene
R824970C006 Simultaneous Removal of Soot and NOx from the Exhaust of Diesel Powered Vehicles
R824970C007 Modeling Gas-Phase Chemistry and Heterogeneous Reaction of Polycyclic Aromatic Compounds
R824970C008 Fundamental Study on High Temperature Chemistry of Oxygenated Hydrocarbons as Alternate Motor Fuels and Additives
R824970C009 Markers for Emissions from Combustion Sources
R824970C010 Experimental Investigation of the Evolution of the Size and Composition Distribution of Atmospheric Organic Aerosols
R824970C011 Microengineered Mass Spectrometer for in-situ Measurement of Airborne Contaminants

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