Tropical monsoon climates have monthly mean temperatures above 18 °C (64 °F) in every month of the year and a dry season. Tropical monsoon climates is the intermediate climate between the wet (or tropical wet climate) and the drier (or tropical savanna climate).
Distribution of Tropical Monsoon Climate
- Occur within 5° to 30° N and S of the equator.
- On-shore [sea to land] tropical monsoons occur in the summer and off-shore [land to sea] dry monsoons in the winter.
- They are best developed in the Indian sub-continent, Burma, Thailand, Laos, Cambodia, parts of Vietnam and south China and northern Australia.
- In the summer, when the sun is overhead at the Tropic of Cancer, a low pressure is created in Central Asia.
- The seas, which warm up much slower, remain comparatively at high pressure.
- At the same time, the southern hemisphere experiences winter, and a region of high pressure is set up in the continental interior of Australia.
- Winds blow outwards as the South-East Monsoon, to Java, and after crossing the equator are drawn towards the continental low pressure area
reaching the Indian sub-continent as the South-West Monsoon (Coriolis force).
- In the winter, conditions are reversed.
- Monthly mean temperatures above 18 °C.
- Temperatures range from 30-45° C in summer. Mean summer temperature is about 30°C.
- In winters, temperature range is 15-30° C with mean temperature around 20-25° C.
- Annual mean rainfall ranges from 200-250 cm. In some regions it is around 350 cm.
- Places like Cherrapunji & Mawsynram receive an annual rainfallof about 1000 cm.
- They lie on the windward side of the Meghalaya hills, so the resulting orographic lift (orographic rainfall) enhancesprecipitation.
The Retreating Monsoon
- The amount and frequency of rain decreases towards the end of the rainy season.
- It retreats gradually southwards after mid-September until it leaves the continent altogether.
- The skies are clear again and the cool, dry season returns in October, with the out blowing North-East Monsoon.
- The role of monsoons in India is vital for its economy.
Tropical Monsoon Forests
- Drought-deciduous forest, dry forest, dry-deciduous forest, tropical deciduous forest.
- Broad-leaved hardwood trees. Well developed in southeast Asia.
- Trees are normally deciduous, because of the marked dry period, during which they shed their leaves to withstand the drought [They shed their
leaves to prevent loss water through transpiration].
- The forests are more open and less luxuriant than the equatorial jungle and there are far fewer species.
- This most early form of farming is widely practiced.
- Instead of rotating the crops in the same field to preserve fertility, the tribesmen move to a new clearing when their first field is exhausted.
- Maize, dry padi, sweet potatoes and some beans are the most common crops.
- Farming is entirely for subsistence i.e. everything is consumed bythe farmer’s family it is not traded or sold.
- As tropical soils are rapidly leached and easily exhausted, the first crop may be bountiful but the subsequent harvests deteriorate.
- Shifting cultivation is so widely practiced amongst indigenous peoples that different local names are used in different countries.
read more : World Climatic Patterns-I