This paper validates the feasibility of aerosol cloud seeding operations in great detail, analyzing inputs such as air volume constraints, chemical concentration levels, particulate size, weight and size constraints of aircraft, number of aircraft employed, and the amount of time required to perform such as operation. Though not an exhaustive study, complex calculations are performed that lend credence to the argument that these aerosol programs, observed in the skies for many years, are quite possible.
An analysis of upper altitude relative humidity data (average relative humidity during this 21 day analysis was 37.5% with a sample standard deviation of 11.7%) in Santa Fe, New Mexico in 1999 refutes the argument that such upper atmospheric conditions should allow for persistent contrails and subsequent cloud formations. It is known at this time that relative humidity levels in the upper atmosphere well below 60% will generally produce clear to semi-clear skies, and normal contrails should dissipate quickly under these conditions. However, the series of pictures included in this paper show the spraying of trails becoming long duration persistent cloud formations that should not have been logically possible with such a low relative humidity on these days of testing.
Aerosols Photographed in Santa Fe, New Mexico by an Independent Photographer