Characteristics in Tropical Climates
- hot ae the sun is overhead and lots of solar radiation reaches the surface
- wet as they are affected by the ITCZ - the low pressure zone of risng air, which cools adn condenses forming frequent heavy rainstorms. Also due to travelling low pressure systems such as subtropical cyclones - they move to the equator, bringing cooler air, winds and rain
...occur in lowland areas within 5-10 latitude of the equator
There is little variation in the length of daylight hours, leads to a small temperature annual range of 3dc - mean monthly temperatures are 26-28dc:
- high humidty and constant temperatures
- daytime temperatures rise to 35dc
- night temperatures fall to 18dc
low pressure throughout the year means close to the equator , pressure gradients are small and winds are gentle. The trade winds converge here
Rainfall is high (2000mm per year) and is repetitive and predictable. The morning is hazy and this clears and condenses to form cumulonimus clouds. Heavy rain develops in the late afternoon and early evening. Rainfall totals double the normal maximum can occur when the sun is directly overhead at the equinox
Tropical Savannah Climates
...occurs within the central parts of large continents between 5-20d either side of the equator. As latitude increases, so does the length of the dry season.
Wet Season:- Temperatures rise above 26dc and there is heavy convectional rain. Totals are greater nearer the equator (1200mm) but can be as little as 500mm.
Dry Season:- (When high pressure dominates) - the peak in temperature coincides with the sun being directly overhead, which corresponds with offshore trade winds blowing across the area from a dry interior source. Winds are strong and steady. On a clear day, temperatures can reach 40dc - at night heat escapes rapidly in clear skies so temperatures can drop to 10dc
...coastal regions between 5-20d N/S between the ITCZ and subtropical high pressure
- Hot temperatures (18-30dc) varying upto 10dc between summer and winter as the sun is always overhead
- High rainfall (3000mm) mostly falls in the wet season
- Winds change directions with the seasons - in the wet season winds blow inland, in the dry season winds blow out to sea
Cool, Dry Season:
The ICZ moves south, Northern Hemisphere monsoon areas lie under high pressure so get little rain. The ITCS is over the ocean and high pressure is over the land. THis forces wind from land to sea. The land is cooler than the ocean so these NE winds are cool and bring lower temperatures.
Warm, Wet Season:
The ITCZ moves north, bringing low pressure and heavy rainfall to the areas in the Northern Hemisphere. The ITCZ over land and high pressure over the sea forces the winds from the ocean inland. The ocean is warmer than the land so the SE winds are warm and bring higher temperatures