(a) Differentiate between weather and climate (b) Name the instruments used in measuring the following weather elements: (i) pressure; (ii) sunshine; (iii) ...

Answer Details

(a) Difference between weather and climate:

Weather is the condition of the atmosphere of a place at a particular time or over a short period (a day or a few days), described in terms of temperature, rainfall, wind, pressure, humidity and sunshine; it changes from hour to hour and day to day. Climate is the average weather conditions of a place taken over a long period, usually not less than 35 years. In short, weather is short-term and changeable while climate is the long-term average.

(b) Instruments used to measure the weather elements:

(c) How wind speed is measured and recorded:

Wind speed is measured with a cup anemometer. It consists of three or four hollow hemispherical cups mounted on horizontal arms fixed to a vertical spindle. The wind catches the open faces of the cups and makes them rotate; the stronger the wind, the faster they spin. The rotating spindle is connected to a dial or counter which records the number of rotations. From the number of turns in a given time the wind speed is read off in kilometres per hour, metres per second or knots. The instrument is mounted on a mast in an open, exposed place, well clear of buildings and trees, so that the free flow of air is not obstructed. Readings are taken at regular intervals and entered in the weather register.