Savanna Climate - Savanna Climate

It is found around the tropical rainforest climate and tropical monsoon climate, and is one of the tropical climates with a clear division between the rainy season (under the equatorial low pressure zone) and the dry season (under the mid-latitude high pressure zone). It is also called a tropical grassland climate. The annual temperature difference is small, less than 8°C, and the highest temperature is just before the rainy season. Due to the influence of the equatorial doldrums and the subtropical high pressure zone, the wind is weak throughout the year. It is distributed between the Tropic of Cancer (latitude 23°26' north and south) on either side of the equator, and the main savanna regions include the Brazilian Plateau (where campo trees grow), the Orinoco River basin (Llano Plain), the west coast of Central America, northern Australia, the Indochina Peninsula, the Deccan Plateau (where regur soil is distributed), and the Congo Basin. In the dry season, the ground becomes dry, the trees lose their leaves and go dormant, and the grass dies, but in the rainy season, the plants start to become active again.

[Yoshitaka Fukuoka]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

熱帯雨林気候と熱帯季節風気候の周辺にみられ、雨期（赤道低圧帯下）と乾期（中緯度高圧帯下）が明瞭(めいりょう)に区分される熱帯気候の一つ。熱帯草原気候ともいう。気温の年較差は8℃以下で小さく、雨期直前に最高気温となる。赤道無風帯および亜熱帯高気圧帯の影響もあり、年間通して風が弱い。赤道を挟む南北回帰線（南北とも緯度23度26分）の間に分布し、ブラジル高原（カンポが茂る）、オリノコ川流域（リャノ平原）、中央アメリカ西岸、オーストラリア北部、インドシナ半島、デカン高原（レグール土が分布）、コンゴ盆地などがおもなサバンナ地域として知られる。乾期は地面がからからになり、樹木は落葉し乾眠し、草は枯れるのに対し、雨期には植物もふたたび活動を開始する。

［福岡義隆］

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