The Effect of Persistence in Cloud Seeding Experiments

Abstract

A basic assumption made in the design of most cloud seeding experiments is that each seeded period is independent of those which preceded it, i.e., that no cumulative effects are present. It now appears that this assumption is not entirely, valid. An investigation is made of the effect of persistence in a typical cloud seeding experiment and it is shown that one consequence is an apparent reduction in the result of seeding with time, There is reason to believe that this has actually occurred in many cloud seeding experiments. A modified design of experiment is suggested which will indicate whether cumulative effects have occurred and will allow a more accurate assessment of the overall result of cloud seeding.