Water in the Atmosphere Test - 3

When the temperature of an air mass containing a large quantity of water vapour falls all of a sudden, condensation takes place within itself on fine dust particles. So, the fog is a cloud with its base at or very near to the ground.

Water is present in the atmosphere in three forms namely – gaseous, liquid and solid. 

The air can only contain a certain amount of water vapour before it is saturated. This amount is dependent on the temperature of the air.

Sleet is frozen raindrops and refrozen melted snow water. When a layer of air with a temperature above freezing point overlies a subfreezing layer near the ground, precipitation takes place in the form of sleet.

The alto clouds are found at low, mid, and high levels.

The condition when the relative humidity is 100% is called saturation level. The temperature at which saturation occurs in a given sample of air is known as dew point.

The temperature at which the water starts evaporating is referred to as the latent heat of vapourisation.

In orographic rainfall, the windward slope of the mountain receives maximum rain and the leeward slope remains generally drier and is known as the rain shadow area. In orographic rainfall, the leeward side of the mountain gets heavy rainfall.

The temperate regions, which include both the westerlies and easterlies, can experience cyclonic rain, but it is most common in the westerlies due to the prevailing wind patterns and atmospheric conditions found in this area.

Condensation takes place: (i) when the temperature of the air is reduced to dew point with its volume remaining constant; (ii) when both the volume and the temperature are reduced; (iii) when moisture is added to the air through evaporation.