Introduction: - Cyclone Gaja in Tamil Nadu
Drastic tropical cyclone
storm ‘Gaja’ brought the disaster in Tamil Nadu. The cyclone also
left hundreds of cattle dead all over Tamil Nadu; numerous crops have been
destroyed by the winds of the cyclone, causing irreparable loss of
livelihood to the farmers.
While no major health problems have been reported post storm, but for those presenting with injuries sustained while clearing the debris, the health department officials seemed on alert.
What are tropical
cyclones?
Tropical cyclones,
also called typhoon or hurricane, an intense circular storm that originates
over warm tropical oceans and is characterized by low atmospheric pressure,
high winds and heavy rain. Drawing energy from sea surface and maintaining its
strength if it remains over warm water.
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| Tropical Cyclone- Shape |
A tropical cyclone
is a rotating, organized system of clouds and thunderstorm. It rotates counter
clockwise in the northern hemisphere. A tropical cyclone generates winds may
exceed 119 km (74 miles) per hour and may surpass 320 km (200 miles) per hour. These
strong winds come with heavy rain and devastating phenomenon known as the storm
surge, and elevation of the sea surface that can reach 6 metered (20 feet)
above normal levels. Such as combination of high winds and water makes
cyclones a serious hazard for coastal areas in tropical and subtropical areas
of the world.
Types of Cyclones
Tropical depression: A tropical cyclone
with maximum sustained winds of 38 mph.
Tropical storm: A tropical cyclone
with maximum sustained winds of 39 to 73 mph.
Hurricane: A tropical cyclone
with maximum sustained winds of 74 mph or higher. In the western north pacific,
hurricanes are called typhoons; similar storms in the Indian Ocean and South
Pacific Ocean are called cyclones.
Major hurricane: A tropical cyclone
with maximum sustained winds of 111 mph or higher, corresponding to a category
3, 4 or 5 on the Saffir Simpson hurricane wind scale.
What are polar cyclones?
Cyclones that
occur in Polar Regions like Greenland, Siberia and Antarctica.
Unlike tropical cyclones, polar cyclones are unusually stronger in winter
months. These storms really do prefer the colder weather. They also occur in
area that aren’t very populated, so any damage they do is usually minimum.
What are mesocyclones?
Mesocyclones occur
when part of a thunderstorm cloud starts to spin, which may eventually lead to
tornado. “Meso means middle”, the mid -point between one type of storm
and the other. Tornadoes all come from thunderstorm clouds, but not all
thunderstorm cloud make tornadoes. This type of cyclone can be devastating as
the clouds are too dangerous as they spin and run along the ground.
Where and when it formed?
Every year during
the late summer months (July-September in the Northern Hemisphere and
January- march in the southern Hemisphere), cyclones strike regions as far
apart as the Gulf Coast of North America. North-western Australia, and eastern
India and Bangladesh.
Tropical cyclones
are known by various names in different parts of the World. In the North
Atlantic Ocean and eastern North Pacific, they are called Hurricanes, and in
the western North Pacific around the Philippines, Japan and China
the storms are referred to as typhoons. In the western South Pacific and Indian
Ocean. They are variously referred to as severe tropical cyclones,
tropical cyclones, or simply cyclones. All these different names refer to the
same type storm.
Impact of Cyclones
Cyclones are
dangerous because they produce destructive winds, heavy rain full of flooding
every year thousands of people died from such devastating events occurred in
several part of the world. The property number of billions gets destroyed every
year. Climate change is also a major reason of occurring such intensive
cyclones.
