Geography - Climatology - Mediterranean Climate (Western Margin Climate) December 23, 2018 Mediterranean Climate (Western Margin Climate) Mediterranean Climate or Warm Temperate Western Margin Climate or Warm Temperate West Coast Climate Distribution Entirely confined to the western portion of continental masses, between 30° and 45° north and south of the equator. The basic cause of this type of climate is the shifting of the wind belts. Mediterranean Sea has the greatest extent of this type of ‘winter rain climate’, and gives rise to the name Mediterranean Climate. The best developed form of this climatic type is found in central Chile. Other Mediterranean regions include California (around San Francisco), the south-western tip of Africa (around Cape Town), southern Australia, and south-west Australia (Swanland). Mediterranean Climate Clear skies and high temperatures; hot, dry summers and cool, wet winters. Mean annual precipitation ranges from 35 – 90 cm. Temperature of warmest month greater than or equal to 10° C. Temperature of coldest month is less than 18° C but greater than –3° C Climate is not extreme because of cooling from water bodies. A dry, warm summer with off-shore trades In summer when the sun is overhead at the Tropic of Cancer, the belt of influence of the Westerlies is shifted a little pole wards. Rain bearing winds are therefore not likely to reach the Mediterranean lands. The prevailing Trade Winds [tropical easterlies] are off-shore and there is practically no rain. Strong winds from inland desert regions pose the risk of wildfires. Rainfall in winter with on-shore Westerlies The Mediterranean lands receive most of their precipitation in winter when the Westerlies shift equator wards. In the northern hemisphere, the prevailing on-shore Westerlies bring much cyclonic rain from the Atlantic (Typical to Mediterranean Climate). The rain comes in heavy showers and only on a few days with bright sunny periods between them. This is another characteristic feature of the Mediterranean winter rain. Though the downpours are infrequent they are often very torrential and in mountainous districts, destructive floods occur. Climate Graphs Local winds of the Mediterranean Climate Many local winds, some hot, others cold are common around the Mediterranean Sea. Sirocco This is a hot, dry dusty wind which originates in the Sahara Desert. It is most frequent in spring and normally lasts for only a few days. The Sirocco blows outwards in a southerly direction (south to north) from the desert interiors into the cooler Mediterranean Sea. After crossing the Mediterranean Sea, the Sirocco is slightly cooled by the absorption of the water vapour. Its scorching heat withers [To dry up or shrivel from loss of moisture] vegetation and crops. This may be ‘blood rain’ because the wind is carrying the red dust of the Sahara Desert. Mistral Mistral is a cold wind from the north, rushing down the Rhone valley in violent gusts between 40 and 80 miles per hour. The velocity of the Mistral is intensified by the funneling effect in the valley between the Alps and the Central Massif [Plateau in France]. A similar type of cold north-easterly wind experienced along the Adriatic coast is called the Bora. Tramontane and Gregale are similar cold winds of the Mediterranean Sea. Natural Vegetation in the Mediterranean Climate Trees with small broad leaves are widely spaced and never very tall. The absence of shade is a distinct feature of Mediterranean lands. Plants are in a continuous struggle against heat, dry air, excessive evaporation and prolonged droughts. They are, in short xerophytic [drought tolerant], a word used to describe the drought-resistant plants in an environment deficient in moisture. Mediterranean evergreen forests These are open woodlands with evergreen oaks. They are found only in the climatically most favored regions. The trees are normally low, even stunted, with massive trunks, small leathery leaves and a wide-spreading root system in search of water. The cork oaks are specially valued for their thick barks, used for making wine-bottle corks and for export around the world. In Australia, the eucalyptus forests replace the evergreen oak. The giant redwood is typical of the Californian trees. Evergreen coniferous trees These include the various kinds of pines, firs, cedars and cypresses which have evergreen, needle-shaped leaves and tall, straight trunks. Mediterranean bushes and shrubs This is perhaps the most predominant type of Mediterranean vegetation. Grass Conditions in the Mediterranean do not suit grass, because most of the rain comes in the cool season when growth is slow. Even if grasses do survive, they are so wiry [lean, tough] and bunchy that they are not suitable for animal farming. Cattle rearing is thus unimportant in the Mediterranean. Agriculture in the Mediterranean Climate Orchard farming The Mediterranean lands are also known as the world’s orchard lands. A wide range of citrus fruits such as oranges, lemons, limes, citrons and grapefruit are grown. The fruit trees have long roots to draw water from considerable depths during the long summer drought. The thick, leathery skin of the citrus fruits prevents excessive transpiration. The long, sunny summer enables the fruits to be ripened and harvested. The Mediterranean lands account for 70 per cent of the world’s exports of citrus fruits. The olive tree is probably the most typical of all Mediterranean cultivated vegetation. Olive oil extracted is a valuable source of cooking oil in a region deficient in animal fat. Besides olives, many nut trees like chestnuts, walnuts, hazelnuts and almonds are grown and the nuts picked as fruits or for the chocolate industry. Crop cultivation and sheep rearing Wheat is the leading food crop. Barley is the next most popular cereal. The mountain pastures, with their cooler climate, support a few sheep, goats and sometimes cattle. Transhumance is widely practiced (moving up and down the hills in search of pastures according to seasons). Wine production Viticulture is by tradition a Mediterranean occupation. Regions bordering the Mediterranean Sea account for three-quarters of the world’s production of wine. Some 85 per cent of grapes produced, go into wine. The long, sunny summer allows the grapes to ripen. Economy Net exporter of citric fruits and net importer of dairy products. Clear skies in summer and good landscapes encourage tourism [Lot of Indian Songs are shot here]. European Mediterranean has many ancient cities and are famous for their health and pleasure resorts, frequented by millions all-round the year.