The Harmattan winds are hot and dry winds which originate from the Sahara Desert and blow towards the Guinea coast of Africa. As these winds arrive on the western coast of Africa, the weather turns into pleasant dry weather with low relative humidity, thus bringing great relief to the people. Due to this reason, they are also known as doctor winds.

Dust particles are generally found in the lower layers of the atmosphere. They are found in the form of sand, smoke-soot, oceanic salt, ash, pollen, etc. Higher concentration of dust particles is found in the sub tropical and temperate regions due to dry winds.Water Vapour is formed in the atmosphere due to evaporation from surface water bodies. It is the source of all kinds of precipitation. It acts as a blanket, allowing the earth to neither become too hot or too cold. Amount of water vapour decreases with altitude.

The Thermosphere is located between 80 and 400 km above the mesopause. It contains electrically charged particles known as ions. It is therefore known as Ionosphere. The temperature here starts increasing with heights. Radio waves transmitted from the earth are reflected back to the earth by this layer. The International Space Station and other satellites orbit in this layer. Auroras are observed in the lower parts of this layer.

The amount of insolation received varies from latitude to latitude. The Regions within the equator and 40° N and S latitudes are energy surplus regions because they receive abundant sunlight and hence more heat will be gained than lost.The Regions beyond 40° N and S latitudes are energy deficit regions because they lose more heat than that gained from sunlight.

Dust particles are generally found in the lower layers of the atmosphere. They are found in the form of sand, smoke-soot, oceanic salt, ash, pollen, etc. Higher concentration of dust particles is found in the sub tropical and temperate regions due to dry winds.

The Stratosphere is the layer of the Earth’s atmosphere which lies beyond the troposphere. It extends up to an altitude of 50 kilometres from the earth’s surface. This layer is almost free from clouds and associated weather phenomenon. It therefore makes conditions most ideal for flying aeroplanes.

The boundary zone when two different type of air masses meet is called a Front. The process of its formation is known as frontogenesis. Differences in terms of tem­perature, humidity, precipitation, cloudiness, and wind direction are experienced along different fronts. Since fronts are formed due to convergence of two air masses of contrasting temperatures and hence contrasting weather conditions are found from north to south or south to north.  Occluded front is formed when cold front over­takes warm front and warm air is completely displaced from the ground surface

Frontal precipitation occurs when a front or boundary line is formed between two air masses of contrasting temperature. Along the fronts, the warm air rises above the denser cold air. The mid-latitude regions experiencing the convergence of warm tropical and cold polar air masses are important areas receiving frontal precipitation.

Albedo is the proportion of insolation that is reflected back by the surface. It depends upon the nature of the surface upon which the solar radiation is incident and the angle of incidence of the solar beam.

Temperature of a place depends primarily on the amount of insolation received. The important factors which affect the atmospheric temperature include:Cloud coverDistribution of land and SeaElevationAspect