Q7.Briefly mention the alignment of major mountain ranges of the world and explain their impact on local weather conditions, with examples.

Mountain ranges are pivotal geographical features that significantly influence regional and local weather patterns due to their elevation and global alignment.

Globally, mountain ranges exhibit distinct alignments. The Circum-Pacific Belt (e.g., Rockies, Andes) runs predominantly North-South. The Alpine-Himalayan Belt (e.g., Alps, Himalayas) extends East-West across Eurasia.

Orographic Lift and Rain Shadow

Mountains act as barriers, forcing moist air to rise (orographic lift). This leads to cooling, condensation, and heavy precipitation on the windward side. The leeward side then experiences a 'rain shadow' due to dry, descending air, resulting in arid conditions. Examples include the Western Ghats causing heavy rainfall on their western slopes and a rain shadow in the Deccan, and similar effects east of the Rockies/Andes.

Temperature and Air Mass Influence

Mountains create altitudinal temperature gradients. They also block or channel air masses. The Himalayas, for instance, block cold Siberian winds from entering India, moderating winter temperatures, and significantly influence the Indian monsoon's distribution.

Local Winds

Adiabatic heating of descending air on the leeward side generates warm, dry local winds like Foehn (Alps) or Chinook (Rockies), impacting local temperatures and snowmelt.

Therefore, the alignment and physical presence of mountain ranges are fundamental determinants of regional climate, shaping precipitation, temperature regimes, and local wind systems globally.