Measurements of the partitioning of hydrogen peroxide in a stratiform cloud¹

1 Contribution number 621.

Abstract

Simultaneous measurements of hydrogen peroxide in cloud droplets and in the air in which the droplets were suspended are presented. In addition, a description of the new technique used to make the measurements is also presented. The ratio of the measured cloudwater concentration to the equilibrium cloudwater concentration predicted using Henry’s law and the measured gas-phase hydrogen peroxide was 0.64 (S.D = 0.32, n= 74). Analysis of both random and potential systematic errors indicate that while this ratio was statistically different from unity, the difference was not considered to be substantial. Henry’s law appeared to have been valid for hydrogen peroxide in the ambient cloud we studied.