Study notes on "Clouds and its types" (part 1)

CLOUD

A cloud is a visible mass of liquid droplets or frozen crystals made of water and/or various chemicals suspended in the atmosphere above the surface of a planetary body.

In general, clouds form when rising air is cooled to its dew point (the temperature at which

the air becomes saturated). Water vapour normally begins to condense on condensation

nuclei such as dust, ice, and salt in order to form clouds. If sufficient condensation particles are

not present, the air will become supersaturated and the formation of cloud or fog will be inhibited The cloud formation is generally due to adiabatic cooling.

Sources of water vapour 

The main sources from which water vapour is added to the air are: 

• wind convergence over water or moist ground into areas of upward motion, 
• precipitation, 
• daytime heating leading to evaporation of water from the surface of oceans, 
• water bodies or wet land and
• transpiration from plants Significance of clouds

Clouds are very significant because:

•  They cause all forms of precipitation.
•  They play a major role in the heat budget of the earth.
•  They reflect, absorb some part of incoming solar radiation as well as some part of long-wave terrestrial radiation reradiated by the earth

Types of CLOUDS:

1. Cirrus clouds: These clouds form above 20,000 feet (6,000 meters) and since the temperatures are extremely low at such high elevations, these clouds are primarily composed of ice crystals. High-level cloud are typically thin and white in appearance, but can appear in a magnificent array of colours when the sun is low on the horizon.

2. Cirro-cumulus: These clouds appear as small, rounded white puffs. The small ripples in the cirrocumulus sometimes resemble the scales of a fish. A sky with cirrocumulus clouds is sometimes referred to as a "mackerel sky."

3. Cirro-stratus: These clouds are thin, sheetlike high clouds that often cover the entire sky. They are so thin that the sun and the moon can be seen through them.

TO BE CONTINUED