Alignment of Major Mountain Ranges:
- Himalayas (Asia) – NW–SE
- Barrier between Indian subcontinent & Central Asia
- Arc-shaped convex southward
- Andes (S. America) – N–S
- Along western coast of South America
- Parallel to Pacific Ocean
- Rockies (N. America) – NW–SE
- From Alaska to New Mexico
- Western edge of North America
- Alps (Europe) – W–E
- Across Central Europe (France to Austria)
- Curved arc
- Urals (Russia) – N–S
- Divides Europe & Asia
- Linear mountain range
- Atlas (Africa) – SW–NE
- Along NW Africa (Morocco to Tunisia)
- Great Dividing Range (Australia) – N–S
- Along eastern Australia coast
Impact on Local Weather Conditions:
- Orographic Rainfall
- Example: Western Ghats (India) – Heavy rainfall on windward side (west), rain-shadow on leeward side (east)
- Example: Andes – Rainfall on eastern slopes, Atacama Desert on western side (rain-shadow)
- Barrier to Monsoons/Winds
- Himalayas block cold Siberian winds; retain monsoon winds over Indian subcontinent
- Rockies deflect westerlies, causing cyclonic weather in central USA
- Desert Formation
- Andes create Atacama Desert (world’s driest)
- Sierra Nevada blocks moisture, forms Great Basin Desert (USA)
- Climate Variation with Altitude
- Example: Alps – Alpine climate; supports varied vegetation zones
- Example: Himalayas – Glacial climate at top, subtropical at base
- Storm Track Modification
- Rockies influence path of jet streams and mid-latitude cyclones
- Himalayas modify Western Disturbances bringing winter rain to North India
Examples for Case Study Reference:
- Atacama Desert (Andes)
- Western Disturbances (Himalayas)
- Great Plains Tornado Belt (Rockies)
Conclusion:
Mountain ranges, by virtue of their orientation and altitude, significantly influence regional climates, precipitation patterns, and human activities across continents.
