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

Model Answer: 

The alignment of major mountain ranges significantly influences local weather conditions across the globe. These ranges act as barriers to air movement, affecting precipitation patterns, temperature distributions, and wind systems.

Major mountain ranges and their alignments:

• Himalayas: East-West across South Asia
• Andes: North-South along western South America
• Rockies: Northwest-Southeast in North America
• Alps: East-West across central Europe
• Great Dividing Range: North-South along eastern Australia

Impact on local weather conditions:

1. Orographic precipitation: Mountains force air masses to rise, cool, and condense, resulting in increased rainfall on windward slopes. This effect is particularly pronounced in coastal ranges, creating lush, wet environments (e.g., Pacific Northwest, USA).

2. Rain shadow effect: As air descends on the leeward side of mountains, it warms and dries, creating arid regions. This phenomenon is responsible for many of the world’s deserts (e.g., Atacama Desert, Chile).

3. Temperature variations: Higher elevations experience cooler temperatures, creating vertical climate zones. This allows for diverse ecosystems within short distances (e.g., Mount Kilimanjaro’s varied biomes).

4. Wind patterns: Mountain ranges can channel or block wind flows, affecting local wind systems and creating unique weather phenomena (e.g., Santa Ana winds, California).

Examples of weather impacts:

• Himalayas: These mountains block cold Arctic air from reaching the Indian subcontinent, contributing to the region’s tropical climate. They also play a crucial role in the formation of the South Asian monsoon by forcing moist air to rise and precipitate.

• Andes: The north-south alignment of this range causes extreme aridity in the Atacama Desert on its leeward side. It also influences El Niño patterns, affecting weather across South America and beyond.

• Alps: These mountains create föhn winds, warm dry winds that descend leeward slopes, significantly impacting temperature and precipitation in surrounding regions (e.g., sudden temperature rises in winter).

Conclusion: Mountain range alignment profoundly shapes local weather patterns, influencing precipitation, temperature, and wind systems across diverse geographical regions.