(a) Define climate. (b) Describe the three climatic belts recognized by the Greek system of climatic classification. (c) Outline three reasons why Koppen&rs...

(a) Definition of climate

Climate is the average weather conditions of a place recorded and generalised over a long period of time, usually not less than 35 years. It considers elements such as temperature, rainfall, pressure, humidity and wind.

(b) The three climatic belts of the Greek system

The ancient Greeks divided the earth into three temperature zones based on distance from the equator and the angle of the sun's rays:

• The Torrid (Tropical) Zone: Lying between the Tropic of Cancer (\(23\tfrac{1}{2}^\circ\)N) and the Tropic of Capricorn (\(23\tfrac{1}{2}^\circ\)S). The sun is overhead at some time of the year, so it is permanently hot.
• The Temperate Zones: Two belts lying between the tropics and the Arctic Circle (\(66\tfrac{1}{2}^\circ\)N) and Antarctic Circle (\(66\tfrac{1}{2}^\circ\)S). They receive slanting rays and experience moderate, seasonal temperatures.
• The Frigid (Polar) Zones: Two belts lying between the polar circles and the poles. The sun's rays are very oblique, so they are permanently cold.

(c) Three reasons why Koppen's system is the most widely accepted

• It is based on measurable, quantitative data (definite values of temperature and rainfall), so it is precise and can be applied objectively anywhere.
• It links climate closely with natural vegetation, making the classification meaningful and easy to relate to the real world.
• It uses a simple system of letter symbols (A, B, C, D, E, etc.) that is concise, easy to remember and allows detailed sub-division of climatic types.