Local winds

Seasonal temperature changes (as well as daily variations) is greatest over the centre of large land masses. This leads to the seasonal winds, called monsoon blowing from the sea to dry land in the summer and outwards from land to sea in winter. India, Asia and China have distinct monsoon effects. Tornado, the origin of which is unclear, are instances of high wind speeds occur. They vortices, several hundred meters in diameter, which move in a clearly defined path. They can happen all over the world, but, fortunately, there are only in certain areas. Their life is short but fierce. Wind speeds of 480 km h-1 or more likely, and the pressure in their heart reached as low as about 800 mm RT century (The lowest atmospheric pressure recorded in the United Kingdom is 925 mbar and higher 1055 mbar. In London values 950 mbar and 1049 mbar, respectively.)

At high altitudes, the relative absence of dust particles and reduce the amount of water vapor in the atmosphere means that radiated out to space is less inhibited the night. The consequence is that the surface of the earth on a hill cools faster at night than at lower altitudes. The air in contact with the colder surface becomes chilled (and therefore denser) and slides down from the mountain side of the low places where this is how a light wind, called the katabatic wind and gravity. Examples are General and typical case Mistral, katabatic wind in the Mediterranean sea from the high plateau of southern and Eastern France.

Other local winds as a result of the passage of air before advancing depression, through the hot desertthe Sahara, for example, which gives the dry wind along the coast of North Africa. (The same wind changes its character in crossing the Mediterranean, becoming warm moist winds in the southern Europe.)

There is another local wind, which results from the process of adiabatic expansion and cooling of the air rises. The air attack on the windward side of the rising slopes expands, rises, cooling arising between the. Temperature below the dew point is reached, clouds form and in due time to come down. The same air, then passes on the highest point of the slope and the rain falls on the leeward side, suffering adiabatic compression and increase in temperature, as it does so. It appears as a dry, warm wind on the leeward side of the earth. An example of this is a Chinook wind blowing down the Eastern slopes of the Rocky mountains.

The last instance of a local wind importance occurs in West Africa during the winter in the Northern hemisphere. The Sahara desert significantly cool at night in the winter causes a progressive reduction of the air temperature, as the season advances. This cold, dry air flows to the West African coast, displacing the warmer and brighter coastal atmosphere..