- Precipitation – 02
- MEDITERRANEAN CLIMATE
A DRY, WARM SUMMER WITH OFF-SHORE TRADES
- RAINFALL IN WINTER WITH ON-SHORE WESTERLIES
LOCAL WINDS OF THE MEDITERRANEAN CLIMATE
- NATURAL VEGETATION IN THE MEDITERRANEAN CLIMATE
Precipitation – 02
- 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).
- Mean annual precipitation ranges from 35 – 90 cm.
- Temperature of warmest month greater than or equal to 10⁰ C.
- Temperature of coldest month is less than 18⁰ C but greater than –3⁰ C
- Climate is not extreme because of cooling from water bodies.
- 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.
- 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.
- Many local winds, some hot, others cold are common around the Mediterranean Sea.
- 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 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.
- 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.