Summer rain
T.S. Karthik, Chennai
During summer, the sun being overhead, there is intense heating of the land and the air above as compared to the surroundings. The air. on being heated, becomes lighter and rises.
As the specific heat of water is higher than that of the land, it takes more time to heat the water, whereas the land gets heated up quickly. This causes air to rise, creating an intense low-pressure condition on the surface. As the air rises, it expands and loses heat.
The warm, moist air on cooling thus, reaches a point called the condensation level, where the water vapour condenses and turns back into a liquid. This process of condensation leads to the formation of clouds in the atmosphere. As the clouds continue to grow and when they cannot bear the weight of water droplets, it leads to precipitation.
This process of rising air is called convection and the type of rainfall which occurs during peak summer is called convectional rainfall.
This process also leads to the formation of Cumulonimbus clouds (formed due to intense low pressure or atmospheric instability), which causes heavy rainfall, but for a short duration accompanied by thunderstorms.
P.S.S. Maheswari,
Hyderabad
This week’s questions
Is it true that everything came from Big Bang including space and time? If it so then why do energy and matter released with the Big Bang occupy space? - T. Narasimman, CHENNAI
How will a reducing sparrow population affect ecological balance? - T.S. Karthik, Chennai
Why does a solar halo occur? - M. Selvakumaran, Chennai
Why there is it necessary to place a desert cooler near an open window, and also to have to leave a door or window open opposite to the cooler? - Vijaypal Yadav, Nagaur, Rajasthan
