Clouds drop generation

For a cloud to generate precipitation, some drops need to grow to precipitable size around 1mm. Growth of droplets can proceed via a series of mechanisms (1) water vapor condensation, (2) droplet coalescence, and (3) ice processes. 

Pressure drop of bed Specific converting power also net transport defined by Eq. (4-7) also dimensionless heat generated or rejected in Figs. 90-91 Flow rate of gas in gas cloud phase... 

Another important aspect of cloud formation is the generation of ice particles at temperatures below the freezing point of water. The spontaneous glaciation of liquid water drops in clouds is a fairly rare event unless the... 

The occurrence of clouds shows dramatic geographical variation and is generally restricted to the lowest 4-6 km of the troposphere. Clouds form and evaporate repeatedly. Only a small fraction (around 10%) of the clouds that form actually generate precipitation. Thus nine out of ten clouds evaporate without ever generating rain droplets. Even in cases where precipitation develops, the raindrops often evaporate on their way falling through the cloud-free air, so the drops never reach the surface. 

This may be a very small dust particle in the atmosphere, a chemical particle generated in a cloud-seeding operation in the atmosphere, or a very small impurity particle present in gas or liquid. Such particles quickly form equivalent bubbles or drops by adsorbing molecules of the water on their solid surfaces, so that they become artificial drops or artificial bubbles of practically constant size. 

CLOUD CHAMBER EFFECT. The cloud chamber effect refers to a mist of tiny water droplets or condensation cloud that is temporarily formed around the fireball generated by a nuclear weapon explosion. This effect is produced by the expansion of air in the negative-pressure phase of the blast wave (a nuclear detonation produces a negative-pressure phase, followed by a positive-pressure phase, which is experienced as the shock wave). The drop in pressure brings about an equivalent drop in temperature, and as a consequence, any water vapor present condenses. See also BHANGMETER. 

---