Question

Write an essay on Thunderstorm

Answer 1

Explanation:

Rain fall in thunderstorms, unlike tropical cyclones, is in the form of heavy downpour with greatest intensity of all other forms of precipitation but is of short duration because of two factors viz.:

(i) the air rises abruptly with great force due to which there is quick condensation and cloud formation, and

(ii) there is abundant absolute humidity due to high rate of evaporation consequent upon very high temperature during summer season.

The rainfall of thunderstorm is closely related to its numerous cells. There is maxi­mum rainfall in the centre and minimum at the periph­ery of each convective cell. Fully developed cell yields rainfall for about an hour whereas weak cell dies out within few minutes.

(ii) Hailstorms:

When condensation occurs be­low freezing point, ice particles are formed which range from the size of a pea to large ball. Hail is not associated with every thunderstorm. Not only this, hail is confined to only certain cells of a thunderstorm. Hails fall down on the ground surface when the rising convection currents become weak and feeble. The sudden fail of hails inflicts great damage to human health and wealth, birds and animals and standing agricultural crops.

(iii) Lightning:

Electrical discharge centres are developed in a mature thunderstorm. The centres of positive and negative electrical charges develop in the upper and lower portions of the clouds respectively with discharge values ranging between 20 to 30 cou­lombs. Lightning is produced when the electrical po­tential gradient between the electrical positive and negative charges becomes very steep.

According to another view lightning is produced due to splitting of large water drops. Each water drop has positive and negative electrical charges which remain in neutral state when they are evenly balanced. This balance is disturbed due to splitting of these drops resulting into difference in positive and negative charges.