Anticyclone, a structural geosingularity


A. Lamine Diop Senior Consultant Management & Strategy




Anticyclone is a structural atmospheral field of high velocity and high pressure rotational wind that occures in oceanic cold-tropical  or cold-mild wind front nearby a littoral. Mostly known anticyclones are Azores, Saint-Helena, Bermuda, Pacques Island, Hawai, Mascarein, Siberia and Antarctic. Other temporary anticyclones are recorded mostly in oceanic cold-mild wind fronts. Most anticyclones are located between 30° to 35° north or south latitude.

Since temperature spread between a cold oceanic area and a nearby tropical or mild area is high enough, a thermal stochastic discontinuity prevails between those two areas. That thermal discontinuity is even higher near the littoral because continental heat transfer are lower, than deep ocean where heat tranfer between hot and cold area is far more swift. Besides, thermal discontinuity is lower with altitude because heat transfer is more perfect.

In such an interface, a tropospheric range of gradient ascendant temperature prevails from top to bottom in 10km and a range of gradient descendent temperature between hot and cold areas, the latter gradient is lower deep sea or with altitude and increases from there to continent. Differently from ordinary tropospheral status, pressure decreases from top to bottom.

Therefore, a thermoaerodynamics is born to reach anticyclone stochastic equilibrium : cold an hot winds converge to a central front area upper troposphere (10km) and mingle down at very high velocity clockwise Northen Hemisphere and unclockwise Southern Hemisphere because of Coriolis force. Down away from central axis of anticyclone, wind depresses and velocity goes lower however with turbulence.


Cold and high pressure mingled wind from upper center anticyclone rotates down, around and aside wider and wider at very high and higher velocity according to a cone-shaped helix and at high and lower pressure before depressing away with tremendous turbulence.


Click here to see anticyclon dynamics



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Azores Anticyclone

Azores anticyclone born might be closely related to turbulent event anterior and/or posterior to blocks detachment.

Anticyclones are meteo giants that impact tremendously tropical, temperate and subsidiarily cold climates all the more ocean climate. Azores anticyclone is an important determinant for nothern Atlantic ocean, european west coast and american east coast climates and the key one for atlantic Cancer tropical climate concerning West and North Africa as well as central and eastern South America.


Azores Anticyclone temperature map altitud-0, winter



Azores anticyclone milders northen Atlantic temperature either european west coast, american east coast or deep Atlantic however with a lot of turbulent winds that jerk ocean permanently and bring fog and storm to both european and american coast. Nevertherless, above mountainous coast anticyclone wind depresses enough to provoke rain and storm rather than fog. During winter, winds bring heat and often provoke cloudburst and sometimes storm in western Europe while upper-layer disturbance causes thunderstorm in american east coast. Winter 1999, anticyclone upper-layer appeal caused a violent storm in  french west coast. However, most violent storms are rather caused by  cyclone. Azores spring is pretty quiet due to decrease of discontinuity spread. Anticyclone summer effects are  cloudburst and thunderstorm in european coast as well as thunderstorm in american coast. During autumn Azores brings drizzle to european west coast and cloudburst to american east coast. Anticyclone moves stochastically and is nearer to northen Atlantic during summer. Because of both Azores and Saint-Helena anticyclones, atlantic ocean stays the jerkier and the stormier.


Anticyclone wind milders West and North African climates and is the key factor for pluviometry. Because of high pressure around anticyclone, water condensation above Sahara is delayed and fog is likely to prevent from any raining in Sahara desert. During winter high pressure lower-layer winds bring fog to North and West Africa however farther away to the south they depress and bring cloudburst. During summer, while anticyclone move up to the north, winds bring cloudburst and storm to West Africa.

Besides Azores brings storm to central America due to upper-layer appeal and fog to eastern south America.



Xynthia storm that touched western France winter 2010 is caused by anticyclone upper-layer appeal. In deed, global temperature is increasing and 2010 is the  hotter since 130 years. Temperature anomaly is high in french west coast at +2.5°c to +5°c lower deep Atlantic at +0.5°c and pretty high in american east coast at +1°c to +2.5°c. As the matter of fact anticyclone  has moved up to the north and upper-layer appeal is of concern with France as soon as deep ocean. The consequence is strong depression above western France toward anticyclone that gives Xynthia storm.



However punctual that may be, anticyclone generally creates temporary and sudden cyclones in its neighboring temperate areas possibly wherever there is a singular positive temperature anomaly.

Cyclones are often violent. Nevertheless, new building technologies such as standardized bolt & nut consolidated foundations and extended-SBNCF for ancient buildings can enhance considerably building resistance to either P or S wave.


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