AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Modeling Smog Chamber Experiments: Forward and Inverse
NASER G. A. MAHFOUZ, Neil Donahue, Carnegie Mellon University
Abstract Number: 825 Working Group: Aerosol Physics
Abstract In environmental smog chambers, it is possible to isolate and study atmospheric particle chemistry and microphysics to illuminate how pollution contributes to the formation and growth of atmospheric aerosol particles. Oxidation of gas-phase precursors results in low-volatility products that condense onto growing aerosol particles. If the concentration of the formed low-volatility products is sufficiently high, they can also nucleate to form aerosol particles. Moreover, low-volatility products can be deposited onto the walls; likewise, suspended particles can be deposited onto the walls. Suspended particles coagulate inside the chamber resulting in bigger particles. Within a chamber, the dynamics of nucleation, condensation, coagulation, and deposition are all coupled; the purpose of this work is to separate these coupled processes to better model chamber dynamics, both forwardly simulating particle population changes and inversely determining the dynamics from available measurements. Where other models rely on ordinary differential equation (ODE) solvers, this work employs partial differential equation (PDE) solvers, since the underlying general dynamic equation (GDE) is a first-order hyperbolic PDE. Moreover, this work expands the space of uncertain parameters to account for more physical phenomena and measurements.