CYCLONE
MICHAUNG - ENVIRONMENT
News:
How Cyclone Michaung
formed, intensified, rained and dissipated |
Explained
What's
in the news?
●
The India Meteorological Department (IMD)
has issued an “orange” alert for Tamil
Nadu and coastal and interior Andhra Pradesh due to the potential landfall
of cyclone Michaung.
Key
takeaways:
●
Tropical cyclones are engines that use warm sea surfaces as fuel to move heat
from the water to the upper atmosphere.
Cyclone:
●
It is a large-scale system of
air that rotates around the centre
of a low-pressure area.
●
It is usually accompanied by violent storms and bad
weather.
●
As per the National Disaster Management
Authority (NDMA), a cyclone is characterised
by inward spiralling
winds that rotate anticlockwise in the northern
hemisphere and clockwise in the southern hemisphere.
Types
of Cyclones:
1.
Tropical cyclones:
●
These develop in the regions between the Tropics of
Capricorn and Cancer.
●
They are the most
devastating storms on Earth.
●
The cyclones develop when thunderstorm
activity starts building close to the centre of circulation, and the
strongest winds and rain are no longer in a band far from the centre.
●
The storm's core turns warm, and the
cyclone gets most of its energy from the “latent
heat” released when water vapour that has evaporated from warm ocean
waters condenses into liquid water.
●
Warm fronts or cold fronts
are not associated with tropical cyclones.
●
Tropical cyclones have different
names depending on their location and strength.
Different
Names of Tropical Cyclones:
●
For instance, they are known as hurricanes in the Caribbean Sea,
the Gulf of Mexico, the North Atlantic Ocean and the eastern and central North
Pacific Ocean. In the western North Pacific, they are called typhoons.
Conditions
favourable for Tropical Cyclones:
The conditions favourable
for the formation and intensification of tropical storms are
●
Large sea surface with
a temperature higher than 27° C.
●
Presence of the Coriolis force.
●
Small variations in the vertical wind
speed.
●
A pre-existing weak low-pressure area or low-level-cyclonic
circulation.
●
Upper divergence above the sea level
system.
2.
Extratropical cyclones:
●
Also known as mid-latitude cyclones, extratropical cyclones occur outside
the tropics, i.e., beyond the areas that fall under the Tropic of Cancer
and the Tropic of Capricorn.
●
They have cold air at their
core and derive energy from releasing potential energy when cold
and warm air masses interact.
●
Such cyclones always have one or more
fronts connected to them.
●
A front is a weather system that
is the boundary between two kinds of air masses, where one
front is represented by warm air and the other by cold air.
●
Such cyclones can occur over land and
ocean.