A Comparison of the Warm Fog Clearing Capabilities of Some Hygroscopic Materials

Abstract

The chemical properties of hygroscopic materials are evaluated to determine the desirable characteristics of in effective warm fog seeding agent. A numerical model is used to determine the relative fog clearing capabilities of the potentially effective chemicals. In general, the results show that the hydroxides and chlorides, when dispensed as dry material, are most effective, while high solubility materials, such as NH4NO3, are most effective when dispensed as saturated solution droplets. Many of the more effective materials are either corrosive or caustic and therefore not practical seeding agents. Of all the chemicals examined, urea and ammonium nitrate are the most practical materials since they are neither corrosive nor caustic and are relatively inexpensive.