Discuss the concept of air mass and explain its role in macro-climatic changes. (200 words)

An air mass is a large body of air with relatively uniform temperature and humidity acquired over a source region.

Concept

• Continental and maritime air masses differ in dryness; tropical, polar and arctic classes differ in temperature.
• Stability, fronts and uplift determine weather when air masses move from source regions.

Macro-climatic effects

• Interactions between contrasting air masses generate fronts, cyclones, precipitation and temperature transitions.
• Seasonal movement of tropical maritime and continental air masses influences monsoon, heat waves and cold waves.
• Jet streams and blocking can redirect air masses, modifying regional climate extremes.

Keywords: source region, continental, maritime, fronts, cyclones, monsoon, jet stream.