WIND :- Wind is the air in motion. It is a horizontal movement of air. When the air is at rest compared to surrounding objects, we are scarcely aware of its presence, but when it is in motion we readily recognise it. The chief cause of wind is the unequal heating of the atmosphere by the sun resulting in differences in the pressure between places. Winds always blow from areas of higher press...

FACTORS EFFECTING ATMOSPHERIC PRESSURE :- Atmospheric pressure depends on three main factors :- 1. Altitude: As you go higher up the pressure of the air decreases. Generally speaking, this decrease in pressure is at a rate. of 1 cm for every 110 meters of ascent. At 5500 meters it is about half that figure and at a height of 48 km it is one-thousand the pressure at sea-level. This is because...

WORLD DISTRIBUTION OF TEMPERATURE :- Isotherms: There is a convenient method of showing the distribution of temperature over the earth or over large areas of the earth. This is done by means of maps employing isotherms. The word "isotherm" means equal heat. Isotherms are imaginary lines drawn on a map, joining places having the same average temperature for a specified period, supposing them to...

NATURE OF THE ATMOSPHERE :- The atmosphere is as much a part of the earth as land or water, although we may not feel, it, except when it moves as wind, it is not as dense as either land or water, but it has weight and exerts pressure. The atmosphere is mobile, elastic and both compressible and expansible. Held to the earth by gravitational attraction, this envelope is densest at sea level and thin...

Karst Topography :- Karst topography is a landscape shaped by the dissolution of a layer or layers of soluble bedrock, usually carbonate rock such as limestone or dolomite. Due to subterranean drainage, there may be very limited surface water, even to the absence of all rivers and lakes. Many karst regions display distinctive surface features, with sinkholes or do-lines being the most common. H...