Kinetic equation of concurrent nucleation and chemical aging of an ensemble of aqueous organic aerosols

TL;DR

This paper derives a new kinetic equation based on classical nucleation theory to model the size and composition evolution of aqueous organic aerosols undergoing nucleation and chemical aging, with implications for climate modeling.

Contribution

It introduces a novel second-order partial differential equation for aerosol distribution, incorporating chemical aging and gas depletion effects, advancing kinetic theory of phase transitions.

Findings

The kinetic equation can be solved via separation of variables.

It accounts for chemical reactions and gas absorption effects.

Potential to improve climate model accuracy.

Abstract

Using the formalism of the classical nucleation theory, we derive a novel kinetic equation for the size and composition distribution of an ensemble of aqueous organic aerosols, evolving via nucleation and concomitant chemical aging. This distribution can be drastically affected by the enthalpy of heterogeneous chemical reactions and the depletion of organic trace gases absorbed by aerosols. A partial differential equation of second order for the temporal evolution of this distribution is obtained from the discrete equation of balance via Taylor series expansions. Once reduced to the canonical form of the multidimensional Fokker-Planck equation, this kinetic equation can be solved via the method of complete separation of variables. The new kinetic equation opens a new direction in the development of the kinetic theory of first-order phase transitions, while its applications to the formation and evolution of atmospheric organic aerosols may drastically improve the accuracy of global climate models.