Nevertheless, the height to which the cloud rises depends upon air temperature and turbulence. These determine how much cooler, ambient air is pulled into the hot cloud and, hence, determine its rate of cooling. The buildup of the agent's concentration is influenced by both the amount and speed of agent release and by existing meteorological conditions. Shortly after release, the agent cloud assumes the temperature of the surrounding air and and moves along its direction and at its speed. The air's turbulence tend to elongate the chemical cloud, tear it apart, and dilute it. The heavier the agent, the longer the cloud retains its integrity. Little decrease in agent vapor concentration is encountered under conditions of low turbulence, and the chemical cloud may travel long distances while with increased turbulence the agent cloud dilutes or dissipates faster.

Click here or image above for reference table of chemical agents.

Aerosols - Aerosols are finely divided liquid and/or solid substances suspended in the atmosphere. Sometimes dissolved gases are also present in the liquids in the aerosols. Chemical agent aerosol clouds can be generated by thermal munitions and aerosols spray devices or as by-products of liquid spray devices and bursting munitions. Airborne aerosols behave in much the same manner as vaporized agents. Initially, aerosol clouds formed from thermal generators have a higher temperature than clouds formed from other types of munitions. This may cause some initial rise of the cloud at the release point. Aerosol-generated clouds are heavier than vapor clouds hence they are less influenced by turbulence, they tend to retain their forms and settle back to earth. However, gravity settles down the larger, heavier parts as the clouds travel downwind. Many particles stick to leaves and other vegetative surfaces they contact.

Franco Dell'Oro except the pages that do not carry this notice. Free for educational and personal use. Cannot be reproduced in print for commercial purposes.