this presentation is all about different kinds of winds and wind system.. hope this will help you a lot in your studies :)

1. WINDS
AND
WIND SYSTEM
S

2. WIND
 is simply defined as air in motion.
 are horizontal flows of air; winds
blow from areas of high pressure
to areas of low pressure (nature
tries to equalise pressure)

3. Factors Affecting The Winds
Pressure Gradient Force
Coriolis Effect
Friction

4. Strong winds also
occur in low latitudes
due to stronger
heating and steeper
pressure gradients.
Hurricanes and
tornadoes are both
tropical phenomena.
Hurricane in Florida Tornado in USA
Wind strength
depends on
the difference
in pressure
between the
high and low
pressure
systems, and
the distance
between
them.
This is called the
PRESSURE
GRADIENT; it is
the spacing of the
isobars which
indicates the
pressure changes
occurring over a
given distance.
ISOBARS are line
connecting places of
equal pressure.

5. CORIOLIS EFFECT
HIGH
LOW
Theoretical wind
which would
result solely from
pressure gradient
Actual wind
which blows, as
diverted by
Coriolis Force
�The earth’s rotation
diverts this wind direction
laterally.This force is
called the CORIOLIS
FORCE.
� The Coriolis force diverts
wind the right in the
northern hemisphere; to
the left in the south.
� The effect is stronger at
high altitude where
ground level friction is less
significant.
HIGH
In the north, winds
blow clockwise out
from a high
pressure. (In the
south, they blow
anti-clockwise).
LOW
In the north, winds
blow anti-clockwise
into a low pressure
system. In the south,
they blow clockwise.

6. Strong polar winds due
to low friction
Beach windbreaks reduce
wind speed by increasing
friction

7. TWO GENERAL TYPES OF
WINDS
 Local Winds
 Prevailing Winds
 Periodic Winds

8. Local Winds
 winds we frequently encounter and
these blow in any direction.
 produced on a local scale by
processes of heating and cooling of
lower air.

9. Two Categories of Local Winds
 Katabatic Wind
 a category includes local winds in hilly
or mountainous regions, where on clear
and clam nights, heat is rapidly lost by
ground radiation.
 This produces a layer of cold.
Katabatic Wind usually felt
on the great ice caps of
Greenland and Antarctica

10.  Convection Wind
 a category that includes land
and sea breezes.
 land and sea breezes are limited to
periods of generally warm, clear weather
when regional wind flows is weak, but
they form an important element of the
summer climate along coasts.

11. Prevailing Winds
 winds that blow from the same
direction and most often travel long
distances.
 also known as PERMANENT WINDS
or PLANETARY WINDS.
 it is sub divided in to the trade
winds, anti trade winds, and polar
winds.

12. Two factors That Affect the
Direction Of Prevailing
Winds
Unequal heating of the
earth’s surface
Earth’s rotation

13. Periodic Winds
 are also known as seasonal
winds or monsoons.
 they blow from water bodies to
land.

14. EARTH’S
SURFACE
WIND SYSTEMS

15. Categories of Wind Systems
 DOLDRUMS
 long known as the equatorial belt of
variable winds and calms.
 this zone is located on a belt of
low pressure.
 it has no strong
pressure gradients to induce persistent
flow of wind.

16.  TRADE WIND BELTS
 these winds are the result of a
pressure gradient
 thus the prevailing wind is from the
northeast and the winds are
termed northeast trade winds
 in the Southern hemisphere, deflection
of moving air towards left
causes the southeast trades

17.  WESTERLIES
 also known as prevailing westerly winds.
 in these belts, storm winds are common
cloudy days with continued precipitation
are frequent.
 weather is highly changeable.
 in Southern hemisphere the westerlies
gain great strength and persistence.

18.  POLAR EASTERLIES
 characteristic wind systems of the Arctic
and Antarctic latitudes is described
as polar easterlies.
 polar easterlies show an
outward spiraling flow.
 radial winds would spiral
counterclockwise, producing a system of
southeasterly winds.

19.  WINDS OF HORSE LATITUDES
 long known as subtropical belts
of variable winds or horse latitude.
 these are not continuous belts
 most of the world’s great deserts lie
in this zone and in the adjacent trade-
wind belt

20. Polar Easterlies
Westerlies
N0rtheast Trades
Southeast Trades
Westerlies
Polar Easterlies