In meteorology, a cyclone is a large scale air mass that rotates
around a strong center of low atmospheric pressure. Cyclones are
characterized by inward spiraling winds that rotate about a zone of
low pressure. The largest low-pressure systems are polar
vortices and extratropical cyclones of the largest scale (the synoptic
scale). Warm-core cyclones such as tropical cyclones and subtropical
cyclones also lie within the synoptic scale. Mesocyclones,
tornadoes and dust devils lie within the smaller mesoscale. Upper
level cyclones can exist without the presence of a surface low, and
can pinch off from the base of the tropical upper tropospheric trough
during the summer months in the Northern Hemisphere. Cyclones have
also been seen on extraterrestrial planets, such as
Cyclogenesis describes the process of cyclone formation
Extratropical cyclones begin as waves in large
regions of enhanced mid-latitude temperature contrasts called
baroclinic zones. These zones contract and form weather fronts as the
cyclonic circulation closes and intensifies. Later in their life
cycle, extratropical cyclones occlude as cold air masses undercut the
warmer air and become cold core systems. A cyclone's track is guided
over the course of its 2 to 6 day life cycle by the steering flow of
the subtropical jet stream.
Weather fronts mark the boundary between two masses of air of
different temperature, humidity, and densities, and are associated
with the most prominent meteorological phenomena. Strong cold fronts
typically feature narrow bands of thunderstorms and severe weather,
and may on occasion be preceded by squall lines or dry lines. Such
fronts form west of the circulation center and generally move from
west to east; warm fronts form east of the cyclone center and are
usually preceded by stratiform precipitation and fog. Warm fronts move
poleward ahead of the cyclone path. Occluded fronts form late in the
cyclone life cycle near the center of the cyclone and often wrap
around the storm center.
Tropical cyclogenesis describes the process of development of tropical
cyclones. Tropical cyclones form due to latent heat driven by
significant thunderstorm activity, and are warm core. Cyclones can
transition between extratropical, subtropical, and tropical phases.
Mesocyclones form as warm core cyclones over land, and can lead to
tornado formation. Waterspouts can also form from mesocyclones,
but more often develop from environments of high instability and low
vertical wind shear. In the Atlantic and the northeastern Pacific
oceans, a tropical cyclone is generally referred to as a hurricane
(from the name of the ancient Central American deity of wind,
Huracan), in the Indian and south Pacific oceans it is called a
cyclone, and in the northwestern Pacific it is called a typhoon.
4 Synoptic scale
4.1 Surface-based types
4.1.1 Extratropical cyclone
184.108.40.206 Polar low
4.2 Upper level types
4.2.1 Polar cyclone
4.2.2 TUTT cell
5.3 Dust devil
5.5 Steam devil
5.6 Fire whirl
6 Climate change
7 Other planets
9 External links
Henry Piddington published almost 40 papers dealing with tropical
storms from Calcutta between 1836 and 1855 in The Journal of the
Asiatic Society. He also coined the term cyclone, meaning the coil of
a snake. In 1842, he published his landmark thesis, Laws of the
Comparison between extratropical and tropical cyclones on surface
There are a number of structural characteristics common to all
cyclones. A cyclone is a low-pressure area. A cyclone's center
(often known in a mature tropical cyclone as the eye), is the area of
lowest atmospheric pressure in the region. Near the center, the
pressure gradient force (from the pressure in the center of the
cyclone compared to the pressure outside the cyclone) and the force
Coriolis effect must be in an approximate balance, or the
cyclone would collapse on itself as a result of the difference in
Because of the Coriolis effect, the wind flow around a large cyclone
is counterclockwise in the
Northern Hemisphere and clockwise in the
Southern Hemisphere. In the Northern Hemisphere, the fastest winds
relative to the surface of the Earth therefore occur on the eastern
side of a northward-moving cyclone and on the northern side of a
westward-moving one; the opposite occurs in the Southern
Hemisphere. In contrast to low pressure systems, the wind flow
around high pressure systems are clockwise (anticyclonic) in the
northern hemisphere, and counterclockwise in the southern hemisphere.
The initial extratropical low-pressure area forms at the location of
the red dot on the image. It is usually perpendicular (at a right
angle to) the leaf-like cloud formation seen on satellite during the
early stage of cyclogenesis. The location of the axis of the upper
level jet stream is in light blue.
Tropical cyclones form when the energy released by the condensation of
moisture in rising air causes a positive feedback loop over warm ocean
Cyclogenesis and Tropical cyclogenesis
Cyclogenesis is the development or strengthening of cyclonic
circulation in the atmosphere.
Cyclogenesis is an umbrella term for
several different processes that all result in the development of some
sort of cyclone. It can occur at various scales, from the microscale
to the synoptic scale.
Extratropical cyclones begin as waves along weather fronts before
occluding later in their life cycle as cold-core systems. However,
some intense extratropical cyclones can become warm-core systems when
a warm seclusion occurs.
Tropical cyclones form as a result of significant convective activity,
and are warm core.
Mesocyclones form as warm core cyclones over
land, and can lead to tornado formation. Waterspouts can also form
from mesocyclones, but more often develop from environments of high
instability and low vertical wind shear. Cyclolysis is the
opposite of cyclogenesis, and is the high-pressure system equivalent,
which deals with the formation of high-pressure
A surface low can form in a variety of ways. Topography can create a
surface low. Mesoscale convective systems can spawn surface lows that
are initially warm core. The disturbance can grow into a wave-like
formation along the front and the low is positioned at the crest.
Around the low, the flow becomes cyclonic. This rotational flow moves
polar air towards the equator on the west side of the low, while warm
air move towards the pole on the east side. A cold front appears on
the west side, while a warm front forms on the east side. Usually, the
cold front moves at a quicker pace than the warm front and "catches
up" with it due to the slow erosion of higher density air mass out
ahead of the cyclone. In addition, the higher density air mass
sweeping in behind the cyclone strengthens the higher pressure, denser
cold air mass. The cold front over takes the warm front, and reduces
the length of the warm front. At this point an occluded front
forms where the warm air mass is pushed upwards into a trough of warm
air aloft, which is also known as a trowal.
Tropical cyclogenesis is the term that describes the development and
strengthening of a tropical cyclone. The mechanisms by which
tropical cyclogenesis occurs are distinctly different from those that
produce mid-latitude cyclones. Tropical cyclogenesis, the development
of a warm-core cyclone, begins with significant convection in a
favorable atmospheric environment. There are six main requirements for
sufficiently warm sea surface temperatures,
high humidity in the lower to middle levels of the troposphere
Coriolis force to develop a low-pressure center
a preexisting low-level focus or disturbance
low vertical wind shear.
An average of 86 tropical cyclones of tropical storm intensity form
annually worldwide, with 47 reaching hurricane/typhoon strength, and
20 becoming intense tropical cyclones (at least Category 3
intensity on the Saffir–Simpson
A fictitious synoptic chart of an extratropical cyclone affecting the
UK and Ireland. The blue arrows between isobars indicate the direction
of the wind, while the "L" symbol denotes the centre of the "low".
Note the occluded, cold and warm frontal boundaries.
The following types of cyclones are identifiable in synoptic charts.
See also: Low-pressure area
There are three main types of surface-based cyclones: Extratropical
cyclones, Subtropical cyclones and Tropical cyclones
Main article: Extratropical cyclone
An extratropical cyclone is a synoptic scale of low-pressure weather
system that does not have tropical characteristics, as it is connected
with fronts and horizontal gradients (rather than vertical) in
temperature and dew point otherwise known as "baroclinic zones".
"Extratropical" is applied to cyclones outside the tropics, in the
middle latitudes. These systems may also be described as "mid-latitude
cyclones" due to their area of formation, or "post-tropical cyclones"
when a tropical cyclone has moved (extratropical transition) beyond
the tropics. They are often described as "depressions" or
"lows" by weather forecasters and the general public. These are the
everyday phenomena that, along with anti-cyclones, drive weather over
much of the Earth.
Although extratropical cyclones are almost always classified as
baroclinic since they form along zones of temperature and dewpoint
gradient within the westerlies, they can sometimes become barotropic
late in their life cycle when the temperature distribution around the
cyclone becomes fairly uniform with radius. An extratropical
cyclone can transform into a subtropical storm, and from there into a
tropical cyclone, if it dwells over warm waters sufficient to warm its
core, and as a result develops central convection. A particularly
intense type of extratropical cyclone that strikes during winter is
known colloquially as a nor'easter.
Main article: Polar low
A polar low over the
Sea of Japan
Sea of Japan in December 2009
A polar low is a small-scale, short-lived atmospheric low-pressure
system (depression) that is found over the ocean areas poleward of the
main polar front in both the Northern and Southern Hemispheres. Polar
lows were first identified on the meteorological satellite imagery
that became available in the 1960s, which revealed many small-scale
cloud vortices at high latitudes. The most active polar lows are found
over certain ice-free maritime areas in or near the Arctic during the
winter, such as the Norwegian Sea, Barents Sea, Labrador Sea and Gulf
of Alaska. Polar lows dissipate rapidly when they make landfall.
Antarctic systems tend to be weaker than their northern counterparts
since the air-sea temperature differences around the continent are
generally smaller. However, vigorous polar lows can
be found over the Southern Ocean. During winter, when cold-core lows
with temperatures in the mid-levels of the troposphere reach
−45 °C (−49 °F) move over open waters, deep convection
forms, which allows polar low development to become possible. The
systems usually have a horizontal length scale of less than 1,000
kilometres (620 mi) and exist for no more than a couple of days.
They are part of the larger class of mesoscale weather systems. Polar
lows can be difficult to detect using conventional weather reports and
are a hazard to high-latitude operations, such as shipping and gas and
oil platforms. Polar lows have been referred to by many other terms,
such as polar mesoscale vortex, Arctic hurricane, Arctic low, and cold
air depression. Today the term is usually reserved for the more
vigorous systems that have near-surface winds of at least
Storm Alex in the north
Atlantic Ocean in January 2016
Main article: Subtropical cyclone
A subtropical cyclone is a weather system that has some
characteristics of a tropical cyclone and some characteristics of an
extratropical cyclone. They can form between the equator and the 50th
parallel. As early as the 1950s, meteorologists were unclear
whether they should be characterized as tropical cyclones or
extratropical cyclones, and used terms such as quasi-tropical and
semi-tropical to describe the cyclone hybrids. By 1972, the
Hurricane Center officially recognized this cyclone
category. Subtropical cyclones began to receive names off the
official tropical cyclone list in the Atlantic Basin in 2002. They
have broad wind patterns with maximum sustained winds located farther
from the center than typical tropical cyclones, and exist in areas of
weak to moderate temperature gradient.
Since they form from extratropical cyclones, which have colder
temperatures aloft than normally found in the tropics, the sea surface
temperatures required is around 23 degrees Celsius (73 °F)
for their formation, which is three degrees Celsius (5 °F) lower
than for tropical cyclones. This means that subtropical cyclones
are more likely to form outside the traditional bounds of the
hurricane season. Although subtropical storms rarely have
hurricane-force winds, they may become tropical in nature as their
Main article: Tropical cyclone
2017 Atlantic hurricane season
2017 Atlantic hurricane season summary map
A tropical cyclone is a storm system characterized by a low-pressure
center and numerous thunderstorms that produce strong winds and
flooding rain. A tropical cyclone feeds on heat released when moist
air rises, resulting in condensation of water vapour contained in the
moist air. They are fueled by a different heat mechanism than other
cyclonic windstorms such as nor'easters, European windstorms, and
polar lows, leading to their classification as "warm core" storm
Hurricane Catarina, a rare
South Atlantic tropical cyclone
South Atlantic tropical cyclone viewed from
International Space Station
International Space Station on March 26, 2004
The term "tropical" refers to both the geographic origin of these
systems, which form almost exclusively in tropical regions of the
globe, and their dependence on Maritime Tropical air masses for their
formation. The term "cyclone" refers to the storms' cyclonic nature,
with counterclockwise rotation in the
Northern Hemisphere and
clockwise rotation in the Southern Hemisphere. Depending on their
location and strength, tropical cyclones are referred to by other
names, such as hurricane, typhoon, tropical storm, cyclonic storm,
tropical depression, or simply as a cyclone.
While tropical cyclones can produce extremely powerful winds and
torrential rain, they are also able to produce high waves and a
damaging storm surge. Their winds increase the wave size, and in
so doing they draw more heat and moisture into their system, thereby
increasing their strength. They develop over large bodies of warm
water, and hence lose their strength if they move over land.
This is the reason coastal regions can receive significant damage from
a tropical cyclone, while inland regions are relatively safe from
strong winds. Heavy rains, however, can produce significant flooding
Storm surges are rises in sea level caused by the reduced
pressure of the core that in effect "sucks" the water upward and from
winds that in effect "pile" the water up.
Storm surges can produce
extensive coastal flooding up to 40 kilometres (25 mi) from the
coastline. Although their effects on human populations can be
devastating, tropical cyclones can also relieve drought
conditions. They also carry heat and energy away from the tropics
and transport it toward temperate latitudes, which makes them an
important part of the global atmospheric circulation mechanism. As a
result, tropical cyclones help to maintain equilibrium in the Earth's
Many tropical cyclones develop when the atmospheric conditions around
a weak disturbance in the atmosphere are favorable. Others form when
other types of cyclones acquire tropical characteristics. Tropical
systems are then moved by steering winds in the troposphere; if the
conditions remain favorable, the tropical disturbance intensifies, and
can even develop an eye. On the other end of the spectrum, if the
conditions around the system deteriorate or the tropical cyclone makes
landfall, the system weakens and eventually dissipates. A tropical
cyclone can become extratropical as it moves toward higher latitudes
if its energy source changes from heat released by condensation to
differences in temperature between air masses. A tropical cyclone
is usually not considered to become subtropical during its
North Indian Ocean cyclone
South Pacific cyclone
Australian region cyclone
South-West Indian Ocean cyclone
Upper level types
Main article: Polar cyclone
A polar, sub-polar, or Arctic cyclone (also known as a polar
vortex) is a vast area of low pressure that strengthens in the
winter and weakens in the summer. A polar cyclone is a
low-pressure weather system, usually spanning 1,000 kilometres
(620 mi) to 2,000 kilometres (1,200 mi), in which the air
circulates in a counterclockwise direction in the northern hemisphere,
and a clockwise direction in the southern hemisphere. The Coriolis
acceleration acting on the air masses moving poleward at high
altitude, causes a counterclockwise circulation at high altitude. The
poleward movement of air originates from the air circulation of the
Polar cell. The polar low is not driven by convection as are tropical
cyclones, nor the cold and warm air mass interactions as are
extratropical cyclones, but is an artifact of the global air movement
of the Polar cell. The base of the polar low is in the mid to upper
troposphere. In the Northern Hemisphere, the polar cyclone has two
centers on average. One center lies near Baffin Island and the other
over northeast Siberia. In the southern hemisphere, it tends to be
located near the edge of the
Ross ice shelf
Ross ice shelf near 160 west
longitude. When the polar vortex is strong, its effect can be felt
at the surface as a westerly wind (toward the east). When the polar
cyclone is weak, significant cold outbreaks occur.
Main article: Upper tropospheric cyclonic vortex
Under specific circumstances, upper level cold lows can break off from
the base of the Tropical Upper Tropospheric Trough (TUTT), which is
located mid-ocean in the
Northern Hemisphere during the summer months.
These upper tropospheric cyclonic vortices, also known as TUTT cells
or TUTT lows, usually move slowly from east-northeast to
west-southwest, and their bases generally do not extend below 20,000
feet (6,100 m) in altitude. A weak inverted surface trough within
the trade wind is generally found underneath them, and they may also
be associated with broad areas of high-level clouds. Downward
development results in an increase of cumulus clouds and the
appearance of a surface vortex. In rare cases, they become warm-core
tropical cyclones. Upper cyclones and the upper troughs that trail
tropical cyclones can cause additional outflow channels and aid in
their intensification. Developing tropical disturbances can help
create or deepen upper troughs or upper lows in their wake due to the
outflow jet emanating from the developing tropical
The following types of cyclones are not identifiable in synoptic
Main article: Mesocyclone
A mesocyclone is a vortex of air, 2.0 kilometres (1.2 mi) to 10
kilometres (6.2 mi) in diameter (the mesoscale of meteorology),
within a convective storm.
Air rises and rotates around a vertical
axis, usually in the same direction as low-pressure systems in both
northern and southern hemisphere. They are most often cyclonic, that
is, associated with a localized low-pressure region within a
supercell. Such storms can feature strong surface winds and severe
Mesocyclones often occur together with updrafts in supercells,
where tornadoes may form. About 1700 mesocyclones form annually across
the United States, but only half produce tornadoes.
Main article: Tornado
A tornado is a violently rotating column of air that is in contact
with both the surface of the earth and a cumulonimbus cloud or, in
rare cases, the base of a cumulus cloud. Also referred to as twisters,
a collequial term in America, or cyclones, although the word cyclone
is used in meteorology, in a wider sense, to name any closed
Main article: Dust devil
A dust devil is a strong, well-formed, and relatively long-lived
whirlwind, ranging from small (half a metre wide and a few metres
tall) to large (more than 10 metres wide and more than 1000 metres
tall). The primary vertical motion is upward. Dust devils are usually
harmless, but can on rare occasions grow large enough to pose a threat
to both people and property.
Main article: Waterspout
A waterspout is a columnar vortex forming over water that is, in its
most common form, a non-supercell tornado over water that is connected
to a cumuliform cloud. While it is often weaker than most of its land
counterparts, stronger versions spawned by mesocyclones do occur.
Main article: Steam devil
A gentle vortex over calm water or wet land made visible by rising
Main article: Fire whirl
A fire whirl – also colloquially known as a fire devil, fire
tornado, firenado, or fire twister – is a whirlwind induced by a
fire and often made up of flame or ash.
This section needs expansion. You can help by adding to it. (July
See also: Hurricanes and climate change
Scientists warn that climate change could increase the intensity of
typhoons as climate change projections show that the difference in
temperature between the ocean – the heat source for cyclones – and
the storm tops – the cold parts of cyclones – are likely to
increase. Climate change is predicted to increase the frequency of
high-intensity storms in selected ocean basins. While the effect
changing climate is having on tropical storms remains largely
unresolved scientists and president of
Vanuatu Baldwin Lonsdale
say the devastation caused by Pam, was aggravated by climate
Cyclone on Mars, imaged by the Hubble Space Telescope
Cyclones are not unique to Earth. Cyclonic storms are common on Jovian
planets, such as the
Small Dark Spot
Small Dark Spot on Neptune. It is about one third
the diameter of the
Great Dark Spot
Great Dark Spot and received the nickname
"Wizard's Eye" because it looks like an eye. This appearance is caused
by a white cloud in the middle of the Wizard's Eye.
Mars has also
exhibited cyclonic storms. Jovian storms like the Great Red Spot
are usually mistakenly named as giant hurricanes or cyclonic storms.
However, this is inaccurate, as the
Great Red Spot
Great Red Spot is, in fact, the
inverse phenomenon, an anticyclone.
^ Glossary of
Meteorology (June 2000). "Cyclonic circulation".
American Meteorological Society. Retrieved 2008-09-17.
^ Glossary of
Meteorology (June 2000). "Cyclone". American
Meteorological Society. Retrieved 2008-09-17.
Weather Glossary (July 2006). "Cyclone". British Broadcasting
Corporation. Archived from the original on 2006-08-29. Retrieved
^ "UCAR Glossary — Cyclone". University Corporation for
Atmospheric Research]. Retrieved 2006-10-24.
Hurricane Center (2012). Glossary of NHC terms. Retrieved
^ I. Orlanski (1975). "A rational subdivision of scales for
atmospheric processes". Bulletin of the American Meteorological
Society. 56 (5): 527–530.
^ a b David Brand (1999-05-19). "Colossal cyclone swirling near
Martian north pole is observed by Cornell-led team on Hubble
telescope". Cornell University. Archived from the original on June 13,
2007. Retrieved 2008-06-15.
^ a b Samantha Harvey (2006-10-02). "Historic Hurricanes". NASA.
^ a b Nina A. Zaitseva (2006). "Cyclogenesis". National Snow and Ice
Data Center. Archived from the original on 2006-08-30. Retrieved
^ a b c d Stan Goldenberg (2004-08-13). "Frequently Asked Questions:
What is an extra-tropical cyclone?". Atlantic Oceanographic and
Hurricane Research Division. Retrieved
^ a b c Forces of Nature. Tornadoes : the mesocyclone. Archived
2008-06-16 at the Wayback Machine. Retrieved on 2008-06-15.
^ a b National
Weather Service Key West summary of waterspout types
^ "Frequently asked questions".
Hurricane Research Division.
^ "Modern Meteorology". Indian Meteorological Department. Retrieved
2011-11-18. [permanent dead link]
^ a b
Chris Landsea and Sim Aberson (August 13, 2004). "Subject: A11)
What is the "eye"? How is it formed and maintained ? What is the
"eyewall"? What are "spiral bands"?". Atlantic Oceanographic and
Meteorological Laboratory. Retrieved 2009-12-28.
^ "The Atmosphere in Motion" (PDF). University of Aberdeen. Archived
from the original (PDF) on 2012-10-18. Retrieved 2011-09-11.
Chris Landsea (2009-02-06). "Subject: D3) Why do tropical cyclones'
winds rotate counterclockwise (clockwise) in the Northern (Southern)
Hemisphere?". Atlantic Oceanographic and Meteorological Laboratory.
^ "Are the winds on one side of a hurricane faster than on the other
side?". Ask the Experts: Hurricanes. USA Today. November 11, 2007.
Retrieved September 9, 2011.
Kerry Emanuel (January 2006). "Anthropogenic Effects on Tropical
Cyclone Activity". Massachusetts Institute of Technology. Retrieved
^ Glossary of
Meteorology (June 2000). "Cyclogenesis". American
Meteorological Society. Retrieved 2009-12-28.
^ Raymond D. Menard; J.M. Fritsch (June 1989). "A Mesoscale Convective
Complex-Generated Inertially Stable Warm Core Vortex". Monthly Weather
Review. 117 (6): 1237–1261. Bibcode:1989MWRv..117.1237M.
^ Glenn Elert (2006). "
Density of Air". The Physics Factbook.
^ St. Louis University (2004-09-06). "What is a trowal?". National
Weather Association. Archived from the original on June 8, 2008.
^ Nina A. Zaitseva (2006). "Definition for Cyclogenesis". National
Snow and Ice Data Center. Archived from the original on 2006-08-30.
^ Cyclon in a board. thethermograpiclibrary.org
Chris Landsea (2009-02-06). "Subject: A15) How do tropical cyclones
form ?". Atlantic Oceanographic and Meteorological Laboratory.
Archived from the original on 2009-08-27. Retrieved 2010-01-01.
Chris Landsea (2000-01-04). "Climate Variability table —
Tropical Cyclones". Atlantic Oceanographic and Meteorological
Laboratory. Retrieved 2006-10-19.
^ a b DeCaria (2005-12-07). "ESCI 241 – Meteorology; Lesson
16 – Extratropical Cyclones". Department of Earth Sciences,
Millersville University, Millersville, Pennsylvania. Archived from the
original on September 3, 2006. Retrieved 2006-10-21.
^ Robert Hart; Jenni Evans (2003). "Synoptic Composites of the
Extratropical Transition Lifecycle of North Atlantic TCs as Defined
Cyclone Phase Space" (PDF). American Meteorological Society.
^ Ryan N. Maue (2008). "Chapter 3:
Cyclone Paradigms and Extratropical
Transition Conceptualizations". Florida State University. Archived
from the original on 2008-05-10. Retrieved 2008-06-15.
^ Atlantic Oceanographic and Meteorological Laboratory, Hurricane
Research Division. "Frequently Asked Questions: What is an
extra-tropical cyclone?". NOAA. Retrieved 2006-07-25.
^ Erik A. Rasmussen; John Turner (2003). Polar lows: mesoscale weather
systems in the polar regions. Cambridge University Press. p. 224.
ISBN 978-0-521-62430-5. Retrieved 2011-01-27.
^ E. A. Rasmussen; J. Turner (2003). Polar Lows: Mesoscale Weather
Systems in the Polar Regions. Cambridge University Press. p. 612.
^ a b c
Chris Landsea (2009-02-06). "Subject: A6) What is a
sub-tropical cyclone?". Atlantic Oceanographic and Meteorological
Laboratory. Retrieved 2009-12-27.
^ David B. Spiegler (April 1973). "Reply" (PDF). Monthly Weather
Review. 101 (4): 380. Bibcode:1973MWRv..101..380S.
^ R. H. Simpson; Paul J. Hebert (April 1973). "Atlantic Hurricane
Season of 1972" (PDF). Monthly
Weather Review. 101 (4): 323.
^ David Mark Roth (2002-02-15). "A Fifty year History of Subtropical
Cyclones" (PDF). Hydrometeorological Prediction Center. Retrieved
Chris Landsea (2009-02-06). "Frequently Asked Questions: What is a
sub-tropical cyclone?". NOAA. Retrieved 2009-12-27.
^ James M. Shultz; Jill Russell; Zelde Espinel (2005). "Epidemiology
of Tropical Cyclones: The Dynamics of Disaster, Disease, and
Development". Epidemiologic Reviews. 27: 21–35.
doi:10.1093/epirev/mxi011. PMID 15958424.
Chris Landsea (2009-02-06). "Frequently Asked Questions: How do
tropical cyclones form?". NOAA. Archived from the original on
2009-08-27. Retrieved 2006-07-26.
^ Sim Aberson (2009-02-06). "Subject : C2) Doesn't the friction
over land kill tropical cyclones?". National
^ National Oceanic and Atmospheric Administration. 2005 Tropical
Eastern North Pacific
Hurricane Outlook. Retrieved on 2006-05-02.
^ Padgett, Gary (2001). "Monthly Global Tropical
Cyclone Summary for
December 2000". Retrieved 2006-03-31.
^ a b Glossary of
Meteorology (June 2000). "Polar vortex". American
Meteorological Society. Retrieved 2008-06-15.
^ Halldór Björnsson (2005-01-19). "Global circulation". Veðurstofa
Íslands. Archived from the original on 2011-08-07. Retrieved
^ Rui-Rong Chen; Don L. Boyer; Lijun Tao (December 1993). "Laboratory
Simulation of Atmospheric Motions in the Vicinity of Antarctica".
Journal of the Atmospheric Sciences. 50 (24): 4058–4079.
^ James E. Kloeppel (2001-12-01). "Stratospheric polar vortex
influences winter freezing, researchers say". University of Illinois
at Urbana-Champaign via the Internet Wayback Machine. Archived from
the original on 2001-12-24. Retrieved 2009-12-27.
^ Clark Evans (January 5, 2006). "Favorable trough interactions on
tropical cyclones". Flhurricane.com. Retrieved 2006-10-20.
^ Deborah Hanley; John Molinari; Daniel Keyser (October 2001). "A
Composite Study of the Interactions between Tropical Cyclones and
Upper-Tropospheric Troughs". Monthly
Weather Review. American
Meteorological Society. 129 (10): 2570–84.
^ Glossary of
Meteorology (June 2000). "Mesocyclone". American
Meteorological Society. Retrieved 2006-12-07.
Weather Service Forecast Office State College, Pennsylvania
Storm and Anti-cyclonic Rotating Mesocyclone
Thunderstorm over Elk County July 10th, 2006". Retrieved
^ Alice Klein and Greta Keenan (8 July 2016). "Perfect storm hits
Taiwan as China sees worst floods in 20 years". New Scientist.
Retrieved 10 July 2016.
^ Robert Mendelsohn, Kerry Emanuel, Shun Chonabayashi and Laura
Bakkensen (2012). "The Impact of Climate Change on Global Tropical
Storm Damages". Nature Climate Change. 2 (3): 205.
SSRN 1955106 . CS1 maint: Multiple names: authors list
^ How climate change makes hurricanes worse on
YouTube August 28, 2017
^ Karl Mathiesen. "Climate change aggravating cyclone damage,
scientists say". The Guardian. Retrieved 10 July 2016.
^ Angela Fritz. "Top hurricane expert: Climate change influenced
Cyclone Pam". The Washington Post. Retrieved 10 July
^ Ellen Cohen (2009). "Jupiter's Great Red Spot". Hayden Planetarium.
Archived from the original on 2007-08-08. Retrieved 2007-11-16.
Wikimedia Commons has media related to Cyclones.
Look up cyclone in Wiktionary, the free dictionary.
Fundamentals of Physical Geography: The Mid-
Cyclone – Dr.
Michael Pidwirny, University of British Columbia, Okanagan
Cyclogenesis – The National Snow and Ice Data
Glossary Definition: Cyclolysis – The National Snow and Ice Data
Weather Facts: The Polar Low –
Weather Online UK
Cyclone Video Archive
The EM-DAT International
Disaster Database by the Centre for Research
on the Epidemiology of Disasters
Fast radio burst
Cosmic rays (Ultra-high-energy cosmic ray)
Solar proton event
Coronal mass ejection
Tidal disruption event
Heat death of the universe
False vacuum metastability event
by death toll
(by death toll)
Structural failures and collapses
by death toll
Mast and tower
Wars and anthropogenic disasters
Battles and other violent events
Emergency population warning
Emergency Alert System
Earthquake warning system
Disaster risk reduction
Global Risk Forum GRF Davos
International Association of Emergency Managers
Disaster and Risk Conference
Disaster Accountability Project
Disaster Emergency Service
Cyclones and anticyclones of the world (Centers of action)
Subtropical cyclone/Subtropical ridge
Azores High (Bermuda/North Atlantic)
North American High (Canadian/Greenland)
South Atlantic High (St.Helena)
North Pacific High (Hawaii High)
South Pacific High
Aleutian Low (Alaska/Far East Russia)
Australian Low (east coast)
Kona storm (Hawaii)
Mediterranean tropical-like cyclone