Send Your Query

 

                         

   

   

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

Mediterranean Climate - Western Margin Climate - 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
  1. California (around San Francisco),
  2. the south-western tip of Africa (around Cape Town),
  3. 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

Mediterranean Climate graph

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].

mistral - central massif - alps

  • 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.

Local winds -Mediterranean

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.

Natural Vegetation-Mediterranean Climate

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.