Tropical savanna climate

A tropical savanna climate is a specific type of weather pattern found in the tropics. Scientists often call it a tropical wet and dry climate. It is defined by two distinct periods of weather. One period brings heavy rainfall, while the other brings very little rain. Under the Köppen climate classification system, these areas are labeled as Aw or As. The Aw label refers to a climate with a dry winter. The As label refers to a climate with a dry summer.

This climate works through a cycle of moisture and dryness. In the wet season, the region receives most of its annual precipitation. In the dry season, the rainfall drops significantly. The driest month must have less than 60 mm of precipitation. It must also have less than 100 mm of precipitation. This cycle is different from a tropical monsoon climate. A monsoon climate has a much wetter period. In a savanna climate, the dry season can become very severe. This often leads to drought conditions during the year.

There are four main versions of this climate based on how rain falls. The first version has wet and dry seasons of roughly equal length. Most of the rain happens in the wet season, and very little falls in the dry season. The second version features a long dry season. This version has seven or more dry months and five or fewer wet months. One extreme of this type is very dry and sits near semi-arid regions. You can find this in India, Northern Australia, Brazil, and the African Sahel. The other extreme has a very short but extremely rainy wet season.

A third version has a long, moderately wet season. This version has seven or more wet months and five or fewer dry months. It is similar to a monsoon climate but does not get enough rain to be called one. This type is often found near the edges of the tropical zone. The fourth version has a dry season with some rain followed by a rainy wet season. This pattern mimics a monsoon climate. However, it lacks the total amount of yearly rainfall needed for that classification. These patterns shape how the land looks and how plants grow.

Geography plays a huge role in where these climates appear. Most savanna climates are located at the outer margins of the tropical zone. However, some are found deep within the tropics, such as in San Marcos, Colombia. These climates are common in Africa, Asia, Central America, and South America. They also exist in parts of northern Australia and the Pacific Islands. You can even find them in south Florida and the Caribbean.

In some places, like Hawaii or parts of Brazil, the dry season occurs in the summer. This is labeled as an As climate. In most other places, the dry season happens during the time of lower sun.

The landscape of a savanna is often defined by its vegetation. Because the land is quite dry, you often see tree-studded grasslands. These are called savannas, which is where the climate gets its name. The area is usually covered in tall, coarse grass. This grass grows because there is not enough constant rain for a thick jungle. It is actually quite rare to find a "pure" savanna that has no trees at all.

Understanding these climates helps us see how the Earth's systems connect. The shifting of the Intertropical Convergence Zone causes the change in seasons. This zone moves based on which hemisphere a location sits in. This movement changes the convection, which affects how much rain falls. By studying these patterns, we see how sun position and wind patterns create different worlds. From the Orinoco river llanos to the coasts of India, the savanna cycle dictates life.