Fog Modification with Long-Chain Alcohols

Abstract

The growth of water drops on condensation nuclei in a supersaturated environment can be greatly retarded by the presence of long-chain alcohols which form monomolecular layers on the liquid surface. The possibility that a fog could be significantly modified using this principle is examined quantitatively, and it is shown that by dispersing practicable amounts of long-chain alcohols it might be possible to produce useful changes of visibility in volumes of the order of 1 km3 Field trials are then described in which about 200 kg of a hexadecanol-octadecanol mixture was released as a finely divided smoke into a valley where fog was expected. In each case, the results were consistent with a modification of the fog throughout a larger volume than expected, but it cannot be claimed that this was not due to natural causes. Assessment of the value of the method is likely to be as difficult as with other forms of cloud seeding.