Gujarat BoardEnglish MediumSTD 11 ArtsGeographyWinds5 Marks
Question
What is wind? Give information about permanent winds by stating the types of winds.
✓
Answer
Wind is the wind that moves in the direction of the horizon.
The types of wind are as follows.
$(1)$ Permanent winds.
$(1)$ East winds $(2)$ Westerly winds $(3)$ Polar winds.
$(2)$ Seasonal winds.
$(1)$ Summer seasonal winds $(2)$ Winter seasonal winds $(3)$ Local winds.
Sea and land waves $(2)$ Mountain and valley waves $(3)$ Chinook and Foen $(4)$ Heat and Norvester $(5)$ Mistral and Bora $(6)$ Sirocco and Hermeton.
$1.$ Permanent winds:
This wind is known as permanent wind as it blows continuously from one direction for many months.
These winds cover many large areas of the earth, moving from the high pressure belt to the light pressure belt.
It is also called planetary wind.
There are three types of winds.
$(1)$ East winds:
These winds are blow in the tropics from the equatorial high pressure belt to the equatorial low pressure belt in both the hemispheres.
The east wind is constantly blowing in one direction at a steady speed.
These winds blow from the east with a slight twist due to the rotational speed of the earth.
Hence these winds are called east winds.
These winds have been used for sea trade in the past as they are moving at a steady pace. Hence they are known as “commercial winds”.
According to Feral's law, the wind blows to its right in the northern hemisphere. It is seen coming from the northeast corner.
That is why he calls it "northeast commercial winds".
In the Southern Hemisphere, it is known as a fiery trade wind because it blows from the angle of fire.
As these winds get warmer towards warmer regions, they increase their moisture storage capacity, but decrease their rainfall capacity.
$(2)$ Westerly winds:
These winds are in both hemispheres from the equatorial high pressure belt to the polar low pressure belt in the temperate zone regions.
These winds blow from southwest in the northern hemisphere, north-east and northwest in the southern hemisphere to the south-east.
So in the northern hemisphere it is called southwest westerly wind and in the southern hemisphere it is called northwest westerly wind.
It is called "counter-trade wind" as the direction of westerly winds is opposite to the direction of commercial winds.
The winds blow from the warmer regions to the colder regions and bring perennial rains to the western regions of Europe, Canada, Chile, etc. on the west coast of the continents.
$(3)$ Polar winds:
These winds are y in both hemispheres from polar high pressure belt to polar low grid belt.
Thus the wind from the poles is known as the polar wind.
Polar winds blow from northeast to southwest in the northern hemisphere and from northeast to southwest in the southern hemisphere.
These winds coming from the poles are extremely cold.
As a result, the cold wave recedes in the regions through which it passes.
The ability to retain moisture in these cold winds is not special so these winds do not give rain.
Cyclonic and counter-cyclonic conditions are created when cold winds from the poles converge with warm winds relative to the temperate zone.
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