1. Particularity of climate characteristics
The Mediterranean climate is characterized by westerlies in winter, frequent frontal cyclones, mild climate, the lowest monthly average temperature of 4 ~ 10℃ and abundant precipitation. Summer is controlled by subtropical high, the airflow sinks, the climate is hot and dry, the clouds are sparse, and the sunshine is sufficient. The annual precipitation is 300 ~ 1000mm, accounting for 60% ~ 70% in winter and only 30% ~ 40% in summer. The climate characteristics of rainy winter and dry summer are unique among various climate types in the world.
2. Typical climatic reasons
The Mediterranean climate is mainly caused by the westerlies in winter, with frequent frontal cyclones. In summer, controlled by the subtropical high pressure belt, the airflow sinks. Among more than ten climate types in the world, the climate types controlled alternately by pressure belts and wind belts throughout the year include tropical grassland climate (controlled alternately by equatorial low pressure belts and trade winds) and tropical desert climate (controlled alternately by trade winds and subtropical high pressure belts) in addition to the Mediterranean climate. The climate controlled by westerlies throughout the year is temperate maritime climate. From the analysis, it can be seen that the investigation of the causes of Mediterranean climate not only examines the students' mastery of the distribution of subtropical high (the maximum influence latitude is 20-40 degrees north and south latitude) and westerly belt (the maximum influence latitude is 30-60 degrees north and south latitude), but also examines the movement of pressure belt and wind belt. It can be said that if students can accurately understand the causes of the Mediterranean climate, it should be easy to understand other climates.
3. Widespread climate distribution
The Mediterranean climate distribution law is located on the west coast of the mainland between 30-40 degrees north and south latitude. Mediterranean climate is the only climate type that exists on all continents except Antarctica. Among the distribution areas of Mediterranean climate, the Mediterranean coast is the most obvious. Other areas such as California coast in North America, central Chile in South America, Cape of Good Hope at the southern tip of Africa and the southwest coast of Australia. Most of its distribution areas are economically developed and are also hot spots in the world.
The Mediterranean climate is also called subtropical summer dry climate. Cs belongs to the climate classification of Keben. It is distributed on the west coast of the mainland between 30 and 40 north latitude. Mainly distributed in the Mediterranean coast, California coast, Chile coast in South America, South Africa and Southwest Australia. The cause is the alternate control of subtropical high and westerly belt. In summer in the northern hemisphere, the planetary wind belt moves northward, and under the control of subtropical high, downward flow prevails, which is hot and dry. In winter, the planetary wind belt moves south, controlled by the westerly wind belt, and the front and cyclone activities are frequent, mild and rainy. The basic characteristics of the Mediterranean climate affected by it are mild and rainy in winter and hot and dry in summer. The average temperature in the hottest month is above 22℃, the average temperature in Leng Yue is about 4 ~ 10℃, and the annual precipitation is 300 ~1000 mm. The seasonal distribution of precipitation is uneven and concentrated in winter. This climate is most typical in the Mediterranean region. Because the Mediterranean is located on the west coast of the mainland. The Mediterranean region is surrounded by mountains, with a vast sea area in the middle, and peninsulas and islands crisscross. The Mediterranean Sea is connected with the Atlantic Ocean through the Strait of Gibraltar. As a result, the west wind can directly drive the Mediterranean coast and be deeply influenced by it. In the high temperature and rainy climate, the natural vegetation is mainly evergreen shrubs with hard leaves.
The origin of south subtropical monsoon climate lies between the largest continent and the largest ocean, and the thermal properties of land and ocean are significantly different. In summer, the Eurasian continental depression is connected, the ocean subtropical high extends westward and advances northward, and the southeast monsoon from the subtropical high in the North Pacific brings abundant precipitation. In winter, the northerly wind from the powerful Mongolian high pressure affects the local area. Because the wind shear meets the requirements of monsoon, it is a monsoon climate.
trait
Summer is hot and rainy: in summer, the sun is high and the temperature is high, and the southeast monsoon blowing from the tropical ocean surface brings abundant precipitation.
Mild and little rain in winter: the average temperature in Leng Yue is above 0 degrees Celsius, and the winter is mild. The reasons are: the local latitude is low, affected by Kuroshio, far away from the source of winter wind, and the topographic relief weakens the winter wind.