What is a Cyclone
Cyclone, atmospheric pressure distribution in which there is a low central
pressure relative to the surrounding pressure. The resulting pressure gradient,
combined with the Cariolis
effect, causes air to circulate about the core of lowest pressure
in a anticlockwise direction in the Northern Hemisphere and in a clockwise
direction in the Southern Hemisphere. Near the surface of the earth, the
frictional drag on the air moving over land or water causes it to spiral
gradually inwardw toward lower pressures. This inward movement of air is
compensated for by rising currents near the center, which are cooled by
expansion when they reach the lower pressures of higher altitudes. The cooling,
in turn, greatly increases the relative humidity of the air, so that "lows"
are generally characterized by cloudiness and high humidity; they are thus
often referred to simply as storms.
pressure relative to the surrounding pressure. The resulting pressure gradient,
combined with the Cariolis
effect, causes air to circulate about the core of lowest pressure
in a anticlockwise direction in the Northern Hemisphere and in a clockwise
direction in the Southern Hemisphere. Near the surface of the earth, the
frictional drag on the air moving over land or water causes it to spiral
gradually inwardw toward lower pressures. This inward movement of air is
compensated for by rising currents near the center, which are cooled by
expansion when they reach the lower pressures of higher altitudes. The cooling,
in turn, greatly increases the relative humidity of the air, so that "lows"
are generally characterized by cloudiness and high humidity; they are thus
often referred to simply as storms.
Different Types of Cyclones
A tropical cyclone is the generic term for a non-frontal synoptic scale low-pressure system over tropical or sub-tropical waters with organized convection and definite cyclonic surface wind circulation
A sub-tropical cyclone is a low-pressure system existing in the tropical or subtropical latitudes (anywhere from the equator to about 50°N) that has characteristics of both tropical cyclones and mid-latitude (or extratropical) cyclones. Therefore, many of these cyclones exist in a weak to moderate horizontal temperature gradient region (like mid-latitude cyclones), but also receive much of their energy from convective clouds (like tropical cyclones). Often, these storms have a radius of maximum winds which is farther out (on the order of 100-200 km [60-125 miles] from the center) than what is observed for purely "tropical" systems. Additionally, the maximum sustained winds for sub-tropical cyclones have not been observed to be stronger than about 33 m/s
An extra-tropical cyclone is a storm system that primarily gets its energy from the horizontal temperature contrasts that exist in the atmosphere. Extra-tropical cyclones (also known as mid-latitude or baroclinic storms) are low pressure systems with associated cold fronts, warm fronts, and occluded fronts.
How do you measure a Cyclone
Cyclones are measured by wind speeds. Whether or not they are classified as a cyclone is also determined by barometric pressure.
How are Cyclones Formed
A tropical cyclone needs two main ingredients: a cluster of thunderstorms and a
warm body of water – at least 27ºC – from which the storm gathers its energy.
The warm, tropical ocean under a developing storm evaporates then condenses to
form clouds, releasing heat throughout the process.
warm body of water – at least 27ºC – from which the storm gathers its energy.
The warm, tropical ocean under a developing storm evaporates then condenses to
form clouds, releasing heat throughout the process.
The heat energy combined with the rotation of the Earth, gets the cyclone
spinning and propels it forward. While the cyclone looks savage from the
outside, its low-pressure centre, commonly known as the eye, is deceptively
calm. This belies the danger of the dense wall of cloud that surrounds it, which
is the deadliest part of a cyclone.
spinning and propels it forward. While the cyclone looks savage from the
outside, its low-pressure centre, commonly known as the eye, is deceptively
calm. This belies the danger of the dense wall of cloud that surrounds it, which
is the deadliest part of a cyclone.
Cyclone Categories
CATEGORY 1
Strongest winds: Gales, 90 - 125 km/h
Negligible house damage. Damage to some crops, trees and caravans. Boats may drag moorings.
Strongest winds: Gales, 90 - 125 km/h
Negligible house damage. Damage to some crops, trees and caravans. Boats may drag moorings.
CATEGORY 2
Strongest winds: Destructive, 125 - 164 km/h
Minor house damage. Significant damage to signs, trees and caravans. Heavy damage to some crops. Risk of power failure. Small boats may break moorings.
Strongest winds: Destructive, 125 - 164 km/h
Minor house damage. Significant damage to signs, trees and caravans. Heavy damage to some crops. Risk of power failure. Small boats may break moorings.
CATEGORY 3
Strongest winds: Very destructive,165 - 224 km/h
Some roof and structural damage. Some caravans destroyed. Power failures likely.
Strongest winds: Very destructive,165 - 224 km/h
Some roof and structural damage. Some caravans destroyed. Power failures likely.
CATEGORY 4
Strongest winds: Very destructive, 225 - 279 km/h
Significant roofing loss and structural damage. Many caravans destroyed and blown away. Dangerous airborne debris. Widespread power failures.
Strongest winds: Very destructive, 225 - 279 km/h
Significant roofing loss and structural damage. Many caravans destroyed and blown away. Dangerous airborne debris. Widespread power failures.
CATEGORY 5
Strongest winds: Very destructive, more than 290 km/h
Extremely dangerous with widespread destruction.
Strongest winds: Very destructive, more than 290 km/h
Extremely dangerous with widespread destruction.
Interesting Facts on Cyclones
Cyclones are also known as hurricanes and typhoons.