Tropical Monsoon Climate: Winds, Rainfall and Economic Activities

The Tropical Monsoon climate, predominant in regions like the Indian subcontinent and parts of Southeast Asia, showcases a unique seasonal reversal of winds, impacting temperature variations and precipitation patterns. Characterized by distinct seasons and heavy rainfall during the monsoon period, it supports diverse vegetation and sustains agricultural practices crucial for local economies.

Tropical Monsoon: Characteristics and Economic Activities

• Distribution: The Tropical Monsoon climate, predominant in regions like the Indian subcontinent and parts of Southeast Asia, showcases a unique seasonal reversal of winds, impacting temperature variations and precipitation patterns. 
  • Characterized by distinct seasons and heavy rainfall during the monsoon period, it supports diverse vegetation and sustains agricultural practices crucial for local economies.
• The Monsoon Phenomenon: The region witnesses complete seasonal reversal of winds. 
  • Best developed in the Indian subcontinent, Burma, Thailand, Laos, Cambodia, parts of Vietnam and south China and northern Australia (50 to 300 N and S of the Equator).  
  • Trade winds after crossing the equator are drawn towards the continental low-pressure area reaching the Indian sub- continent as the South-West Monsoon.
• Climate 
  • Temperature: Average monthly temperature > 180C, Maximum temperature can reach 450C ; 
    • Average temperature in summer is around 300C and during winters is around 250C.
  • Seasons: Cool, dry season (October to February); 
    • The hot dry season (March to mid June); 
    • The rainy season (mid June to September).
  • Rainfall: Concentrated heavy rainfall in summers; 
    • Mean annual rainfall is about 150 cm but there are temporal and spatial variations.
    • Example: Cherrapunji and Mawsynram receive exceptionally high annual rainfall, around 1000 cm,

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• Vegetation
  • Dry–deciduous forests with broad-leaved hardwood trees. E.g., Teak.
  • Less luxuriant than tropical forests with fewer species
  • Broad-leaved Hardwood Trees: Found in Southeast Asia, adapt by shedding leaves during dry periods to save water.
  • In heavy rainfall regions like southern Burma, peninsular India, northern Australia, and coastal regions with a tropical marine climate, vegetation is lush. 
  • Scattered Trees and Tall Grass: As summer rainfall decreases, forests turn into thorny scrubland or savanna with scattered trees and tall grass. 
  • Some parts of the Indian subcontinent become semi-deserts due to low summer rainfall. 
  • Livelihoods: People in these regions depend on diverse vegetation for their livelihoods, including forests, thickets, savannas, and scrubland, supporting activities like farming and grazing.
• Economic activity
  • Supports high-population density.
  • Subsistence Farming: with intensive cultivation in regions with irrigation facilities.
  • Shifting cultivation: It is followed in North-East India and South-East countries.
    • Primitive farming method practiced widely.
    • Farmers move to new clearings when soil is exhausted.
    • Crops include maize, dry padi, sweet potatoes, and beans.
    • Farming is solely for subsistence.
    • Example: Jhum (North-east India), Taungya (Burma), Tamrai (Thailand), Caingin (Philippines), Humah (Java), Chena (Sri Lanka), Milpa (Africa and Central America)
  • Agriculture: wet paddy cultivation, lowland cash crops (sugarcane, jute, Indigo, cotton), Highland plantation crops (Tea, coffee, spices).
  • Plantation Crops: Europeans introduced plantation agriculture to cooler monsoonal highlands.
    • Tea and coffee are the main crops, primarily grown in Brazil, Central America, India, and Java.
  • Coffee: Originated in Ethiopia and Arabia.
    • Brazil leads global production, mainly on the eastern slopes of its plateau.
  • Tea: Originated in China, grown mainly in the Himalayan foothills, central Sri Lanka, and western Java.
  • Lumbering: Valuable timber, especially teak, is harvested in continental Southeast Asia.
  • Cattle and sheep rearing are prevalent.

Tropical Marine Climate

• Distribution: Climate is under the influence of the on-shore Trade Winds all the year-round. Experienced along the eastern coasts of tropical lands: Central America, West Indies, north-eastern Australia, Philippines, parts of East Africa, Madagascar, Guinea Coast and eastern Brazil.
• Climate 
• • Rainfall:  Rainfall (both orographic and convectional) is maximum in summer, but without any distinct dry period; Influence of onshore trade winds. 
  • Prone to severe tropical cyclones, hurricanes or typhoons.
• Vegetation: Rainforests, mangroves, and coastal vegetation; Constant moisture and warmth contribute to the growth of diverse plant species.

Conclusion

The Tropical Monsoon climate, found in regions like the Indian subcontinent and Southeast Asia, is characterized by seasonal winds, heavy rainfall, and distinct temperature changes. This climate sustains diverse vegetation, from lush forests to dry scrublands, supporting livelihoods through farming and grazing. Similarly, the Tropical Marine climate along eastern coasts experiences year-round influence from trade winds, fostering rich rainforests and coastal vegetation despite the threat of tropical cyclones.

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