Binary homogeneous nucleation: Temperature and relative humidity fluctuations and non-linearity.

摘要

This report discusses binary homogeneous nucleation involving H(sub 2)SO(sub 4) and water vapor is thought to be the primary mechanism for new particle formation in the marine boundary layer. Temperature, relative humidity, and partial pressure of H(sub 2)SO(sub 4) vapor are the most important parameters in fixing the binary homogeneous nucleation rate in the H(sub 2)SO(sub 4)/H(sub 2)O system. The combination of thermodynamic calculations and laboratory experiments indicates that this rate varies roughly as the tenth power of the saturation ratio of H(sub 2)SO(sub 4) vapor. Furthermore, the vapor pressure of H(sub 2)SO(sub 4) is a function of temperature, and similar dependencies of the binary homogeneous nucleation rate on relative humidity can be noted as well. These factors thus introduce strong non-linearities into the system, and fluctuations of temperature, relative humidity, and H(sub 2)SO(sub 4) vapor concentrations about mean values may strongly influence the nucleation rate measured in the atmosphere.