It has been mentioned before on this website repeatedly that aerosols serve as cloud condensation nuclei and thus have a substantial effect on cloud properties and their ability to produce rain.
Rain was forecast for Wednesday the 18th of September in Northland, which I was a bit annoyed about, as a friend and I had plans to take photos outdoors that day. However, Tuesday was a day of very heavy aerosol spraying activity and rain that was forecast did not eventuate on the Wednesday. Coincidence? It was a sunny day, without rain.
As well as reducing rainfall, aerosol researcher, Clifford Carnicom, who is based in New Mexico, has found that aerosol spraying is associated with relatively high levels of conductivity of the soil. Conductivity is a direct measure of the concentration of ions in solution. Reactive metal hydroxide salt forms, such as those that have now been documented at unexpectedly high levels in both the atmosphere and rainwater, are exactly the type of salt forms which will increase the conductivity (ion concentration) of the soil as well, he writes. More: The Salt of Our Soils. Increasing Salt Levels Affect Flora, Trees and Plant Life, (2005).
Here are some photos of the aerosol trails seen on Tuesday, the 17th of September. Photos are taken from Woodhill, Whangarei.