Equations for the sensitivity of the equilibrium mass concentration of organic particulate matter with respect to changes in ambient parameters: A technical note

Equations are developed for the expected changes in the equilibrium levels of organic particulate matter (OPM) and aerosol water as may be caused by changes in a range of system parameters that includes temperature T  , the governing gas/particle partitioning coefficients, the mean molecular weight of the absorbing PM phase MW¯ (g mol−1), the total gas + particle concentrations of one or more of the condensable organic species, and the gaseous water concentration. These equations will be useful when considering how PM levels may respond to changing system parameters. The equations are developed for organic + water systems assuming equilibrium gas/particle partitioning theory as developed previously [Pankow, J.F., 1994. An absorption model of gas/particle partitioning of organic compounds in the atmosphere. Atmospheric Environment 28, 185–188].