Air is a mixture of gases that exerts pressure in all directions. Uneven heating of the Earth's surface causes wind currents as warm air rises and is replaced by cooler air. Convection currents occur due to rising warm air and sinking cool air and help distribute the Sun's heat globally. Thunderstorms develop from strong upward winds carrying water droplets that freeze and fall as rain or hail, along with changes in air pressure. Cyclones form due to these pressure changes and can cause severe damage to life and property from high winds. Effective safety measures include early warning systems, shelters, and preparing necessary supplies.

2.  Air is a mixure of gases
 It is everywhere
 Moving air is called wind

3.  Air exerts pressure upward,
downward and sideward .
 It is due this pressure banners or
flags flutter

4.  Difficult to ride a bicycle against the
direction of the wind.
 Easier to row a boat if the wind is
coming from behind.

5. Air pressure
 High speed winds are accompanied by reduced air
pressure.
Hold a narrow strip of paper near
your mouth and blow across the
top. The air moves faster above
than below, and the paper will rise.

6. AIR PRESSURE
 when high speed winds are blew over
the roofs of houses , if the roofs are
weak they could be lifted and blown
away

7. AIR EXPAND ON HEATING
 On heating the air expands and
occupies more space, when the same
thing occupies more space it becomes
lighter. The warm air is therefore
lighter than the cold air .That is the
reason the smoke goes up

8. AIR PRESSURE
 In nature there are several situations
when warm air rises at places .the air
pressure at that place is lowered. The
cold air from the surroundings rushes
in to fill the place .this set up
convection in air.

9. convection
 What is convection?
 "Convection" has several, related meanings in weather....but it always
involves rising air. It usually refers to "moist convection", where the excess
water vapor in rising air parcels condenses to form a cloud.
The heat released through this condensation can help to sustain the
convection by warming the air further and making it rise still higher, which
causes more water vapor to condense, so the process feeds on itself.
But convection can also be dry, as occurs on a sunny day over the desert, or in
more humid regions early in the day before the convection has become strong
enough to form clouds. The sun warms the ground, and convective air currents
help to remove the excess heat from the surface. Dry convection also occurs
during the day even when clouds are not forming...you just can't see
it.Interesting facts:MAKING THE EARTH LIVEABLE: Convection (both dry and
moist) help to make the Earth liveable by removing excess heat from the
surface, which is where most of the solar energy is abrobed by the Earth, and
transporting it high into the atmosphere. It has been calculated that, without
convection, the average surface air temperature on the earth would be about
125 deg. F, rather than the current 59 deg. F.WHAT GOES UP, MUST COME
DOWN: All of the air rising through convection must be balanced by an equal
amount of sinking air elsewhere. This, clouds represent vertical
circulation systems, involving rising air where the visible cloud forms, and
sinking air around the cloud.

10. WIND CURRENTS ARE GENERATED DUE TO
UNEVEN HEATING ON THE EARTH

11. WIND CURRENTS ARE GENERATED DUE TO
UNEVEN HEATING ON THE EARTH
 Regions close to equator get maximum
heat from the sun. the air in these regions
gets warm. The warm air rises and the
cooler air from the regions in the 0-30
degrees latitude belt either side of the
equator moves in. At the poles the air is
colder than that at latitudes about 60
degrees. The warm air at these latitudes
rises up and the cold wind from the polar
regions rushes in to take its place .in this
way wind circulation is set up from the
poles to warmer places.

12.  Thunderstorms develop in hot humid
tropical areas like India very frequently.
The rising temperatures produce strong
upward rising winds. these winds carry
water droplets upwards where they freeze
and fall down again. The swift movement of
the falling water droplets and along with
raising air create lightning and sound. It is
this event we call it as thunder storm.

14.  Before cloud formation water takes up heat from the
atmosphere to change into water vapour.when water
vapour changes back to liquid forms as rain drop lets
this heat is released to the atmosphere. The heat
released to the atmosphere warms the air around.
This air tend to raise and cause s a drop in pressure.
More air rushes to the centre of the storm. This cycle
is repeated. the chain of events ends with the
formation of very low pressure system with very high
speed winds revolving around it. It is this weather
condition that we call it as a cyclone.

16. FORMATION OF CYCLONES

17. DESTUCTION CAUSED BY CYCLONES
 High speed winds accompanying a
cyclone can cause damage to houses.

18.  Cyclone can damage communication
system
DESTUCTION CAUSED BY CYCLONES

19. DESTUCTION CAUSED BY CYCLONES
 CAUSE SEVERE DAMAGE TO LIFE
AND PROPERTY.

20. IF A STORM IS ACCAMPANIED BY LIGHTNING
WE MUST TAKE THE FOLLOWING
PRECAUTIONS.
 Open vehicles are not safe to travel
 Carrying an umbrella is not at all a
good idea
 If in forest take shelter under short
trees
 Stay away from poles and other
metal objects.

21. EFFECTIVE SAFETY MEASURES
 A cyclone forecast and warning
service

22.  Rapid communication of warnings to
the ports, fisher men ships and
general public
EFFECTIVE SAFETY MEASURES

23. EFFECTIVE SAFETY MEASURES
 Construction of cyclone shelters.

24. ACTION ON PART OF THE PEOPLE
 We should not ignore the warnings
issued by the meteorological
department through T.V. Radio

25. ACTION ON PART OF THE PEOPLE
 Make necessary arrangements to shift
the essential household goods
domestic animals and vehicles .

26. ACTION ON PART OF THE
PEOPLE
 Avoid driving on roads through floods

27. ACTION ON PART OF THE PEOPLE
 Do not drink water that could be
contaminated

28. ACTION ON PART OF THE PEOPLE
 Don't touch wet switches and fallen
power lines

29. ACTION ON PART OF THE PEOPLE
 Do not go out just for sake of fun

30. ACTION ON PART OF THE PEOPLE
 Do not pressurize the rescue force by
making undue demands.