ABSTRACT
The climate is understood as the weather averaged over a long period of time, typically 30 years (recommended by the World Meteorological Organization (WMO)). The classification of the world climates relies on some climatic parameters, such as temperature and precipitation. As one of the most widely used climate classification systems, the Köppen climate classification divides the world climates into five major types: tropical climate, dry climate, temperate climate, continental climate and polar climate. It is interesting that the different climates are selected with close reference to native vegetation, which is the best reflection of local climate. Tropical climate, as reflected by its name, is the hot climate typical in the tropics. The general understanding is that the area within the Tropics of Cancer and Capricorn belongs to the tropical climatic zone (see Figure 1.1). However, latitude is not the only parameter which can govern the climatic boundary. Typical tropical climate can be found beyond 23°26´. The tropical climate is of very great importance. Occupying approximately 40 per cent of the land surface of the earth, the tropics are the home to almost half of the world’s population. Compared to the climate at mid-latitude, the tropical climate supports more lives and economic activities in the region. The four principal tropical areas include tropical Asia (India, Malaysia, Philippines, Indonesia, Singapore, northern Australia and so on), tropical Africa (the Congo Basin in West Africa, Mozambique, Angola and so on), tropical America (the Amazon Basin in Brazil, Argentina, Costa Rica and so on) and the tropical oceans and oceanic islands. But the climate is not uniform in the tropics. There are two broad climatic categories. One category is the warm and humid regions with excessive rainfall and considerable sunshine. It provides ideal growing conditions for luxuriant tropical plants and tropical rainforests. The other is hot and dry regions with extreme high temperature during daytime, little precipitation, low vapour pressure and low relative humidity. In these regions, deserts, semi-deserts, steppes and dry savannahs exist.
