(i) Coastal zone is exposed to natural forces including cyclones and Tsunamis.
(ii) Cuddalore and Nagapattinam are situated on the Sea-Shore.
(iii) Cuddalore and Nagapattinam are vulnerable to storms.
(iv) During Summer Bay of Bengal subject to intense heat cause to raise the humid and unstable air masses that produce cyclone.

Auroras are cosmic glowing lights produced by a stream of electrons discharged from the Sun's surface due to magnetic storms that are seen as unique multicolored fire works hanging in the polar sky during mid night.

(i) Polar Easterlies blow form the high pressure areas of the Polar highs at the North and South Poles towards low pressure areas within westerlies at high altitudes.
(ii) When air moves near the poles, cold temperatures shrink the air. So Polar Easterlies are cold and dry.

Cyclones can be classified into
(i) Tropical cyclones
(ii) Temperate cyclones
(iii) Extra Tropical cyclones

(i) A visible mass of condensed water vapour floating in the air above the ground level is called is cloud.
(ii) Cool moisture laden air gets collected around particles like dust, salt content from the sea, smoke, etc, and forms clouds.
(iii) Sometimes mixing warmer and cooler air also produces clouds.

The amount of heat received from the sun in the form of short waves is called insulation (or) incoming Solar Radiation

(i) The blanket of air that surrounds the Earth is called the atmosphere.
(ii) It is held close to the earth by gravitational attraction.
(iii) Atmosphere plays on important role in predicting weather phenomenon.
(iv) It is a mixture of gases, water vapour and dust particles in different proportion.

(i) With little water and food left for humans, sailors used to throw the horses into the sea in order to make the vessels lighter.
(ii) Henceforth these belts (or) latitudes are called as "horse latitudes".

Sometimes drizzles are combined with fog and hence reduce visibility.

The equatorial low pressure belt is an area of calm because
(i) At the equator the earth gets heated by the vertical sun rays and in turn heats the air in contact with it.
(ii) The heated air expands and raises upwards resulting in a low pressure belt.
(iii) This belt is called doldrums due to virtual absence of surface winds.
(iv) Doldrums lies in the equatorial region with calms, light unpredictable winds and sudden cyclones.

It blows from the polar high pressure belt to the sub polar low pressure belt and they become weak.

According to their height, clouds are classified into the following types
(i) High clouds (6 - 20 km Height)
(ii) Middle clouds (2.5 km - 6 km Height)
(iii) Low clouds (ground surface to 25 km height)
These major types of clouds are further divided into different types on the basis of shape and structure.
High clouds
Cirrus: Detached clouds in the form of white delicate fibrous silky filaments formed at the high sky (8000 meters to 12000 meters) are called Cirrus clouds. These clouds are dry and do not give rainfall.
Cirro-cumulus: White patched, sheet or layer like clouds composed of ice crystals.
Cirro-stratus: Smooth milky transparent whitish clouds composed of tiny ice crystals,
Middle clouds
Alto-stratus: Thin sheets of grey or blue coloured clouds in uniform appearance, consisting of frozen water droplets.
Alto-cumulus: clouds fitted closely together in parallel bands, called as 'Sheep clouds' or wool pack clouds.
Nimbo stratus: These are clouds of dark colour very close to the ground surface associated with rain, snow or sleet.
Low clouds
Strato-cumulus: Grey or whitish layer of non-fibrous low clouds found in rounded patches at a height of 2500 to 3000 metres, associated with fair or clear weather.
Stratus: Dense, low lying fog-like clouds associated with rain or snow.
Cumulus: Dome-shaped with a flat base often resembling a cauliflower, associated with fair weather.
Cumulo-nimbus: Fluffy thick towering thunderstorm cloud capable of producing heavy rain, snow, hailstorm or tornadoes.

Atmosphere:
The blanket of air that surrounds the Earth is called the atmosphere. The five atmospheric layers are Troposphere, Stratosphere, Mesosphere, Thermosphere and Exosphere.
Troposphere: The lowest layer of the atmosphere is the troposphere. The Greek word 'tropos' means 'turn' or change. The layer extends up to 8 kms at the poles and up to 18 kms at the Equator. The temperature decreases with increasing height. Almost all weather phenomenon take place in this layer. Hence it is called weather making layer. The upper limit of the troposphere is called as tropopause.
Stratosphere: Stratosphere lies above the troposphere. It extends to a height of about 50 km above earth surface. Since this layer is a concentration of ozone molecules, it is also referred as ozonosphere.The temperature increases with increase in height in this layer, Large jet planes normally fly here. The upper limit of the stratosphere is called as stratopause.
Mesosphere: Mesosphere extends between 50km and 80km. The temperature increases with increasing height. Radio waves transmitted from earth are reflected back to earth from this layer: Most of the meteors nearing the earth, get burned here. The upper most limit of the mesosphere is the mesopause.
Thermosphere: Thermosphere exists above the mesosphere. It extends to about 600 km. The composition of gases in the lower thermosphere is more or less uniform, hence it is called "Homosphere". The upper portion of the thermosphere has uneven composition of gases and hence it is referred as "Heterosphere". Here the temperature increases with increasing height.Ionosphere is a layer of the thermosphere that contains Ions. and free electrons.
Exosphere: The uppermost layer of the atmosphere is called exosphere. This layer is extremely rarefied with gases and gradually merges with the outer space. This zone is characterized by aurora Australis and aurora borealis