Atlantic hurricane

Hurricane is (east of the International Dateline ) called a tropical cyclone in the northern Atlantic Ocean and the North Pacific east of 180 ° longitude and the South Pacific east of 160 degrees East. Even in the Caribbean Sea and the Gulf of Mexico these storms are called hurricanes. This must at least reach hurricane strength, ie wind force 12 on the Beaufort scale ( equivalent to more than 64 knots or 118 km / h). Hurricanes usually arise from May to December, most of them from July to September. The official hurricane season lasts in the Atlantic Ocean and in the central North Pacific from June 1 to November 30, in the eastern North Pacific it starts on May 15.

Linguistic

Naming and demarcation

The word hurricane is evolved from the concept of Huracán, who referred to the Taino and Mayan languages the " God of Wind ". Other names for tropical cyclones are cyclone and typhoon. In the Indian Ocean ( Bay of Bengal and Arabian Sea ) and in the southern Pacific Ocean is called a tropical cyclone as a cyclone. As a typhoon is called a tropical cyclone in East and Southeast Asia and in the northwestern part of the Pacific Ocean, west of the International Date Line and just north of the Equator. On the Mediterranean storms are occasionally observed, similar to tropical cyclones. Such a storm is also called medicane, a combination of the expressions Mediterranean Sea (English for the Mediterranean) and Hurricane (English for hurricane ). The in German literature occasionally encountered term Willy Willy is a common slang term in Australia for a whirlwind, so do not for a tropical cyclone.

Spelling and pronunciation

The online -Duden German spelling lists for the hurricane both the German [ hʊrikan ] as well as the English pronunciation [ hʌrɪkən ], where the English is called first. In German pronunciation is the most hurricanes in English, however the hurricane. The printed Duden 2005 calls pronunciation [ harikən ], the [( ː ) n hʊrika ] appearing next in dictionaries of Pons. The also common in the German pronunciation / hœrikɛn / ( Hörrikän ), which inspired by the American pronunciation is given in any dictionary.

Hazard potential

The high winds, waves and heavy precipitation of a hurricane are a grave threat Represent lead to storm surge, wind damage, coastal erosion, landslides, flash floods and floods.

The highest ever taught material damage in August 2005 with approximately $ 81 billion Hurricane Katrina. Katrina moved with wind speeds of 250 to 300 km / h over Florida, Louisiana - in particular over the Greater New Orleans, Mississippi, Alabama and Tennessee away and claimed over a thousand lives.

The largest number of deaths caused by an Atlantic hurricane, namely about 22,000 lives, caused the Great Hurricane of in 1780.

The largest measured to date hurricane is Hurricane Wilma. With 882 millibars prevailed in the center of Wilma's the lowest air pressure ever recorded in the Atlantic. In addition, Wilma intensified from 18 to 19 October 2005 and is faster than all other observed hurricanes in just a few hours from a tropical storm with wind speeds below 113 km / h to a Category 5 hurricane ( 282 km / h).

If a hurricane reaches the frontal zone of middle latitudes at all, he has already lost more of its harmful energy and is then usually to an extratropical low pressure system ( extratropical transition) or downgraded to a lower category. Such a weather system is still able to bring heavy rains to Europe.

The severity of an upcoming Atlantic hurricane season is predicted every year by the National Oceanic and Atmospheric Administration ( NOAA) and, separately, from the Tropical Risk Consortium ( TSR ) and a team at Colorado State University by a weather forecast.

Mode of origin and life cycle

Hurricanes generally arise in the trade wind zone above the waters of the Atlantic or eastern Pacific, at a water temperature of about 26.5 ° C. If a uniform temperature gradient to great heights towards exceeds a certain level, a tropical cyclone can form. The water evaporates in large quantities and rises through convection. Condensation is great clouds are formed.

This condensation huge bodies of water uses enormous amounts of energy released ( latent heat). The air within the cloud is heated thereby, expands, and then increases with the not yet rained residual moisture further. About the warm sea surface, creating a vacuum and flows from the environment then air with a high proportion of water vapor after. This creates a zone above the hurricane clouds very high air pressure, from which the air in an oppositely directed vortex redistributed ( anticyclone ).

However, the area that covers a hurricane, much too large for a single closed air parcel could make that rises as a whole. Typical of all tropical cyclones, therefore, is the emergence of spiral rain bands where prevail thermal updrafts and intermediate zones where slightly cooler and drier air descends again - without the rain. Afterflowing moist air rises into the rain bands, and constantly provides water and power after. The flowing on the ground air masses are mixed by the Coriolis force in rotation, a large-scale vortex is formed.

If a hurricane near land, so also his ground-level power supply currents shift partly over land, thereby considerably drier air from entering the system and reduce power. Taking a hurricane more than country, largely dried up its waters and thus its energy supplies: he gradually loses its strength and is first to the (weaker ) Tropical Storm, only to lose themselves as a tropical depression.

The meteorological and thermodynamic function of a hurricane is that it takes up huge amounts of heat from the surface of the tropical oceans and first transported into the air and then towards the poles, in the height of the energy is then radiated gradually into space.

Important conditions for tropical storm formation are:

The intensity of tropical cyclones is followed by empirical evidence of the surface temperature of the sea. It should be noted that these temperatures for unknown reasons, may vary over a period of several decades. In the North Atlantic, the Atlantic Multidecadal Oscillation (AMO ) at a rate of about 40 to 80 years changes between hot ' and ' cold ', while in the Northeast Pacific, the Pacific Decadal Oscillation every 20 to 30 years is undergoing a similar change. Especially in the North Atlantic, a trend can be seen here that when, warm ' AMO significantly more intense hurricane seasons occur as in, cold '. Thus, seven of the ten most intense hurricane seasons occurred in 1925 (since measurements began in 1850 ) in the penultimate two AMO warm phases of ~ 1850 to ~ 1900 and ~ to ~ 1965. In the next cold phase, which lasted until the early 1990s, there were only relatively mild hurricane seasons, however. Since about 1995, the AMO is back in a warm phase, which is why the hurricane intensity has increased significantly again in vogue. Researchers at the National Oceanic and Atmospheric Administration believe that this period of increased hurricane intensity in the Atlantic Ocean is about 10 persist for up to 40 years. The occurrence of the El Niño phenomenon increases the probability of wind shear on the east coast of the United States, therefore, fall into this El Niño years with a reduced probability of hurricane - together (for the west coast is contrary to the case).

Places of origin

Hurricanes generally arise in the trade wind zone in the Atlantic Ocean usually southwest of the Cape Verde Islands, in the area of the Caribbean, the West Indies and the Gulf of Mexico, from smaller disturbances of the trade wind, pull the just south of the Sahara desert, starting across the Atlantic. This region of the places of origin of most hurricanes is also called Hurricane Alley.

In the Pacific Ocean, most hurricanes form south of Acapulco; they usually pull out to the open sea or turn off to the north, where they move over Baja California and can reach the Mexican mainland.

With Hurricane Vince formed on October 9, 2005, the first since "Spain - hurricane " of 1842 a tropical cyclone off the coasts of southern Europe and North Africa in the eastern Atlantic. Vince formed between the Azores and the Canary Islands, but weakened before reaching the European mainland to a storm off.

Tropical Storm Delta, Hurricane Epsilon, as well as Tropical Storm Zeta also arose in 2005 in the eastern Atlantic, so have reached the shores of Europe in a year with Vince and Delta, the first two hurricanes.

Wind speed

As defined by the Saffir - Simpson scale is called a hurricane when the wind speed exceeds 64 nodes, that is, 12 Beaufort achieved:

The destructive power of a hurricane grows roughly as the cube of the wind speed.

The stated values of wind speed based on a 1- minute average, as used in the USA. The conversion factor for the corresponding 10 -minute-average is 0.88.

The resulting wind speed over the ground is derived from the movement of the center ( pulling speed, see below) and the orbital revolution motion of the vortex. The fact that hurricanes are left-handed, so add in eastward direction the train speed and the rotation speed, which commonly leads to the highest wind speeds in this region. In the pulling direction to the left, however, the rotational speed is reduced by the train movement; in shipping this area, therefore, as a navigable quarter ( rare: navigable semicircle ) is called. The rotation speed also increases with increasing proximity to the center and is in the eyewall around the almost windless eye is greatest.

A hurricane with up to 100 km in diameter can reach wind speeds of over 200 km / h; in the most vulnerable areas to the right of the direction of pull of a devastating hurricane category 5 and 300 km / h be exceeded.

Development and behavior

To be distinguished from the wind speed is the train speed of the hurricane. It is measured by the movement of the eye relative to the ground. Although Atlantic hurricanes move shortly after the emergence of predominantly west to northwest and often veer between the 20th and 25th degree of latitude north to northeast, as is to be expected neither mandatory nor sure this typical behavior.

From quasi- stationary hurricanes, which weakened himself by bringing cooler ocean water to the surface, to prancing, lurching and loop-shaped curves above ground everything 's already been observed. Even after withdrawing east hurricanes and unexpected short-term changes in direction such as sudden turning to the southwest can not be excluded.

Hurricanes get their energy from the evaporation of warm surface water. Meet them during their train on land, so her supply of energy weakens and they lose strength. Deep Lying just inland regions are therefore affected by the wind speed is less fierce. As well as large bodies of water are in the hurricane basin in the clouds from raining these clouds can also bring hundreds of miles from the coast as Tropical Cyclone gigantic amounts of precipitation with it.

Predicting the tensile direction and the strength of hurricanes is important to warn the population in the affected areas in time and to evacuate if necessary.

According to current knowledge is for the "web" of the hurricanes in the long term the position of the Azores high critical. In the current position, which held the Azores High BP since 1000 and previously between 5000-3400 BP, hurricanes reach both the Atlantic and the Gulf Coast. Between 3400 and 1000 BP the Azores High was to the southwest, approximately over the Bermudas, and therefore drew significantly more hurricanes in the Gulf of Mexico. Paläotempestologische investigation showed that during this time, three to five times more hurricanes reached the Gulf Coast, but only half as many of the Atlantic coast.

Names of hurricanes

Originally only special hurricanes were given a name, such as " New England Hurricane". 1950 began the National Weather Service with the naming of hurricanes. In that year and the following year were first names in use, which corresponded to the time the international phonetic alphabet - that is Able, Baker, Charlie, and so on English women's names were introduced in 1953. From 1960 predefined lists of names were used, each with 21 names. The number 21 has been set, because the most active Atlantic hurricane season in 1933 with 21 registered tropical cyclones had the hitherto highest activity; it has so far exceeded only in 2005. In 1979 we first started using alternating male and female names, also added to the list of the names used by French and Spanish names.

There are currently six permanent, from the World Meteorological Organization ( WMO) established lists of names that are used at intervals of six years. Thus, the lists of the year 2006 will be used again in 2012, with the exception of the names that are deleted by the WMO in the Atlantic and eastern Pacific, 2012. This is done at the request of the meteorological service of the countries affected by a decision of the World Meteorological Organization, when a hurricane has done particularly bad damage. So the name "Ivan" was, for example, with three other names that were used in 2004, no longer in the list for 2010 - "Ivan" was replaced by " Igor". Most storm name of a season - five - were so far removed from the list of names that was applied in 2005: Dennis, Katrina, Rita, Stan and Wilma.

During the first storm of each year in the Atlantic and eastern Pacific always has a name that starts with an A, is (starting at 140 ° West ) in each of the next name in the list assigned central Pacific, regardless of year or letters.

Example: The Atlantic tropical cyclone before hurricane " Katrina " was called " Jose ". In " Katrina " was followed by " Lee" and "Maria". Since the first named storm of each year with "A" starts, one can easily see how many storms there have been: " Katrina " was the 11th storm of 2005, "Mary " of 13

If this is insufficient " name stock " in a year, the following tropical storms are named after the Greek alphabet. It was first and so far only time in the 2005 season, as the 22 tropical storm of the season Alpha, Beta of 23, the 24th Gamma, the 25th and the 26th Delta Epsilon were called. The occurred only a month after the official season tropical storm number 27 was called accordingly Zeta, another would get the name Eta. If one of the named after the Greek alphabet storms cause such severe damage that the name is deleted from the list, the storm name is indeed found to be deleted, the name still remains available in the future.

Season lists

1492-1600 | 1601-1700 | 1701-1799 | 1800s | 1810s | 1820s | 1830s | 1840s | 1850s | 1860s | 1870s | 1880-1884 | 1885 | 1886 | 1887 | 1888 | 1889 | 1890 | 1891 | 1892 | 1893 | 1894 | 1895 | 1896 | 1897 | 1898 | 1899 | 1915 | 1919 | 1928 | 1935 | 1950 | 1951 | 1952 | 1953 | 1954 | 1955 | 1956 | 1957 | 1958 | 1959 | 1960 | 1961 | 1969 | 1970 | 1971 | 1972 | 1973 | 1974 | 1975 | 1976 | 1977 | 1978 | 1979 | 1980 | 1981 | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 | 1988 | 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014

1960 | 1961 | 1962 | 1963 | 1964 | 1965 | 1966 | 1967 | 1968 | 1969 | 1970 | 1971 | 1972 | 1973 | 1974 | 1975 | 1976 | 1977 | 1978 | 1979 | 1980 | 1981 | 1982 | 1983 | 1984 | 1985 | 1986 | 1987 | 1988 | 1989 | 1990 | 1991 | 1992 | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | 2009 | 2010 | 2011 | 2012 | 2013 | 2014

For more see Category: Tropical cyclone season.

Notable hurricanes

Great Hurricane of 1780, Caribbean
Galveston Hurricane in 1900, USA
Okeechobee Hurricane 1928, USA
Labor Day Hurricane in 1935, USA
Hurricane Hattie in 1961, Central America
Hurricane Flora in 1963, Caribbean
Hurricane Dora (1964 ), 1964, USA
Hurricane Camille in 1969, USA
Hurricane Ginger in 1971, North Carolina, Atlantic Ocean
Hurricane Fifi in 1974, Honduras, Belize, Guatemala ( 8,000 to 10,000 deaths)
Hurricane David in 1979, Caribbean (about 4,000 deaths )
Hurricane Allen in 1980, Caribbean
Hurricane Gilbert in 1988, Caribbean
Hurricane Hugo in 1989, Caribbean, USA
Hurricane Andrew in 1992, USA
Hurricane Mitch in 1998, Nicaragua, Honduras
Hurricane Charley in 2004, Cuba, United States
Hurricane Frances in 2004, Bahamas, United States
Hurricane Ivan in 2004, Grenada, Jamaica, Cuba, United States
Hurricane Jeanne in 2004, Haiti, United States
Hurricane Dennis in 2005, Cuba, United States
Hurricane Katrina in 2005, USA
Hurricane Rita in 2005, Cuba, United States
Hurricane Stan in 2005, Central America
Hurricane Vince in 2005, the Azores, Canary Islands, Spain
Hurricane Wilma in 2005, Mexico, United States
Hurricane Dean in 2007, Mexico, Belize, Caribbean
Hurricane Felix in 2007, Nicaragua, Honduras
Hurricane Ike in 2008, Cuba, United States
Hurricane Irene 2011, USA
Hurricane Sandy in 2012, Caribbean, USA

Southern Hemisphere:

Hurricane Catarina in 2004, Southern Brazil

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