Hailstones and Snowflakes

Hailstones and Snowflakes Hailstones Not all the ice crystals in a precipitation cloud fall down onto the earth in the form of raindrops. If these drops pass through a layer of very cold air on their way down, their outer surface freezes. They then change into little...

The Mechanics of Rain Formation

The Mechanics of Rain Formation When water evaporates from the earth’s surface, it is carried into the atmosphere as invisible vapour. Mainly because the vapour-laden air cools as it rises, a point is reached when the air is no longer able to hold water in the...

The Clouds

The Clouds Meteorologists classify clouds by their structure. The first classification of clouds is due to Luke Howard, who in 1803, introduced the Latin names Cirrus, Cumulus, Nimabus and Stratus for different clouds. The International Cloud Atlas published by the...

Withdrawal of the Monsoon

Withdrawal of the Monsoon The change from a summer to winter type of circulation with the retreat of the sun to the south of the equator is of shorter duration than the reversal from winter to summer. It is much more gradual than the abrupt changes associated with the...

The Story of a Raindrop

The Story of a Raindrop One of the major constituents of the atmosphere is water. But, water is found in several different forms. It comes down as liquid drops of rain, or in a frozen state in the form of snow crystals. It exists in a gaseous form as water vapour and...

Condensation Nuclei

Condensation Nuclei Condensation nuclei have an important role to play in the conversion of vapour to liquid water. These are the aerosols which are found floating in the atmosphere. They act as embryos on which the first drops of water form. It is possible to...