THE MECHANISM OF ATMOSPHERIC ICE FORMATION, I: THE CHEMICAL COMPOSITION OF NUCLEATING AGENTS

Abstract

A careful study has been made of the nucleating ability of various chemicals. The nuclei were prepared in a nitrogen atmosphere, rather than air, to prevent a reaction at the hot filament with atmospheric oxygen. With use of these carefully controlled conditions, numerous materials previously reported as effective were found to be poor nucleating agents. The discrepancies among the various sets of data were found to be due to reaction at the filament of the solid material and oxygen in previous investigations. The results are examined to determine how they support prevailing theories on ice-crystal formation.