NOTES WINDS
Light
breeze is a wind with a speed of from 7 to 11 kilometers per hour, Fresh breeze is a wind with a speed of
from 31 to 39 kilometers per hour and Gale
is a wind with a speed of from 63 to 74 kilometers per hour.
Due to rotation of the earth, in the Northern hemisphere
winds are deflected to their right and in Southern hemisphere to their left.
This is known as Ferrel’s Law of Deflection. It is also called Coriolis Effect. The deflection is greatest at the poles and
decreases to zero at the equator.
The Intertropical
Convergence Zone (ITCZ) is the area encircling the earth near the Equator where winds originating in the
northern and southern hemispheres come together.
Westerlies are also known as ‘roaring Forties’ or
Furious Fifties’ or Shrieking Sixties in Southern hemisphere, as
they gather force in the absence of any land mass.
Cyclone, in strict
meteorological terminology, an area of low atmospheric pressure surrounded by a
wind system blowing, in the northern hemisphere, in a counterclockwise
direction. In the southern hemisphere these wind directions are reversed.
The
closer to the center of the cyclone, the faster is the wind speed.
Tropical
cyclones with wind speeds greater than 62.4 kmph are called tropical storms.
Once the wind speeds exceed 118.4 kmph, tropical storms graduate to the label
of a hurricane, or typhoon depending on which part of the world
it is. Hurricanes are severe tropical storms that form in the southern Atlantic
Ocean, Caribbean Sea, Gulf of Mexico, and in the eastern Pacific Ocean, east of
the International Date Line. If the severe storm originates over the North
Pacific, west of the Date Line, it is called a typhoon. Australians, who have
colorful names for just about everything, have their own term for hurricanes:
"willy-willys. Everywhere else it would be called a cyclone
A
tornado is a violently rotating column of air which is in contact with
both a cumulonimbus
cloud base and the surface of the earth. While hurricanes, typhoons and
cyclones have diameters of the scale of hundreds of kilometres and consist of a
dozen to several storms, tornadoes have diameters of the scale of hundreds of
metres and are produced from a single storm. Tornadoes have been observed on
every continent except Antarctica; however,
most of the world's tornadoes occur in the United States. Other areas which commonly
experience tornadoes include New Zealand,
western and southeastern Australia,
south-central Canada, northwestern and central Europe, Italy, south-central and
eastern Asia, east-central South America
and Southern Africa.
Mid-latitude or Temperate
Cyclones are large traveling atmospheric cyclonic storms up to 2000
kilometers in diameter with centers of low atmospheric pressure. They are the
result of the dynamic interaction of warm tropical and cold polar air masses
at the polar front
(around 60 deg latitude).
LOCAL WINDS
Abroholos
(Sudden frequent wind that occurs from May through August on the coast of Brazil)
Alize (northeasterly across central Africa and the
Caribbean)
Alizé Maritime (a wet,
fresh northerly wind across west central Africa)
Amihan (northeasterly
wind across the Philippines)
Bayamo (a violent wind on Cuba's
southern coast)
Blizzard Very
cold winds in Tundra region
Bora (cold dry
wind from eastern Europe to northeastern
Italy)
Brickfielder
Hot wind in Australia
Chili This hot, dry and dusty wind comes from the
Sahara desert in Tunisia
Chinook (warm
dry westerly off the Rocky Mountains) It is also called ‘Snow eater’
Etesian (Greek
name) or Meltemi (Turkish name)
(northerly across Greece and Turkey)
Föehn (warm dry
southerly off the northern side of the Alps and the North Italy)
Fremantle Doctor
(afternoon sea breeze from the Indian Ocean which cools Perth, Western
Australia during summer)
Gregale
(northeasterly from Greece)
Habagat (southwesterly
wind across the Philippines)
Harmattan (hot
dry northerly wind across central Africa It is also called ‘guinea doctor’)
Khamsin
(southeasterly from north Africa to the eastern Mediterranean)
Khazri (cold north wind in
the Azerbaijan Republic)
Kona (southeast wind
in Hawaii, replacing trade winds, bringing high humidity and
often rain)
Košava (strong
and cold southeasterly season wind in Serbia)
Levanter
(easterly through Strait of Gibraltar in Spain)
Libeccio
(southwesterly towards Italy)
Marin
(south-easterly from Mediterranean to France)
Mistral (cold
northerly from central France and the Alps to Mediterranean)
Nor'easter (a
strong storm with winds from the northeast in the eastern United States,
especially New England)
Nor'wester (A
wind that brings rain to the West Coast, and warm dry winds to the East Coast
of New Zealand) Within India also during
monsoon we get Norwester
Pampero, (cold wind
in the Argentina)
Papagayo, a
periodic wind which blows across Nicaragua and Costa Rica
Punas cold dry
wind blowing down towards the western side of Andes
Purga Cold wind
in Russian tundra
Santa Ana (hot winds in southern California)
Simoom (strong, dry, desert
wind that blows in the Sahara, Israel, Jordan, Syria, and the desert of Arabia)
Sirocco (hot
moist wind from north Africa to southern
Europe)
Solano This is another name
for the Levanter
Tramontane (cold
northwesterly from the Alps to the Mediterranean, similar to Mistral)
Yamo Warm and dry winds in Japan
Zonda, winter foehn (a warm, dry wind blowing down the
side of a mountain) in Argentina, where it blows from the west across the Andes Mountains.