○Cyclone, any large wind system that circulates counterclockwise north of the equator around a center with low air pressure
and clockwise south. Cyclone winds cross almost all regions of the world except the equator belt and are in general
connected to rain or snow In the same regions, anti-cyclones are also manufactured, wind systems that revolve around a high-pressure center.
The anti-cyclones are so named because they have a flow that is opposite to that of the cyclones, that is, a spiral movement outwards, with the winds rotating clockwise.
in the northern hemisphere and counterclockwise in the south. These winds are generally not as strong as the cyclone type and generally do not produce precipitation.
Follow a short treatment of the cyclones. For a complete treatment, go to Climate Cyclones and Anti-Cyclones.
○Cyclone refers to any spinning storm that rotates around a low-pressure center. The low-pressure center is also referred to as the 'eye' of the storm,
which is well known for being eerily calm compared with the areas under the spinning 'arms' of the storm. You could say that the eye is watching what's going on down below,
so it needs a clear path, but the arms are where all the action happens because this is where the storm is throwing out all of its rain and wind.
○"Tropical" refers to the geographic origin of these systems, which are formed almost exclusively in tropical seas. "Cyclone" refers to its winds which move in a circle,
revolves around his clear central eye, with the winds blowing counterclockwise in the northern hemisphere and clockwise in the southern hemisphere.
The opposite direction of traffic is due to the Coriolis effect. Tropical cyclones usually form on large bodies with relatively warm water.
They get their energy from the evaporation of water from the surface of the sea, which eventually condenses into clouds and rain when the humid air rises and cools to saturation.
This energy source differs from cyclonic storms of medium width such as the northeast storms and European wind storms.
They are mainly due to the horizontal temperature contrasts. Tropical cyclones generally have a diameter between 100 and 2,000 km (62 and 1,243 miles).
○The first graph is based of the PDI from the 21st Century and the 20th Century combined. The orange is the 21st Century and the Blue is the 20th Century, as you can see the orange line drastically climbs up from the beginning of our century ,this is due to Climate Change as we have broken up the Ozone the climate and the weather on our planet has become some what arbitrary.The second graph there shows only the 20th century so we can compare and contrast between them both. In the 20th century the most the PDI ever reached was 4.0137 in 1999 with it averaging a PDI of 2.4 before hand. This data shows that coming into this latest century something has happened to cause such a drastic change in our storms, and that change is Climate Change
○ Major hurricanes are defined as those of category 3, 4 or 5 on the Saffir–Simpson hurricane wind scale (SSHWS). The
SSHWS classifies storms based on the intensity of sustained winds. Major hurricanes have potential for significant loss
of life and damage.
○Tropical cyclones with maximum sustained surface winds of less than 17 m/s (34 kt, 39 mph) are usually called "tropical depressions"
(This is not to be confused with the condition mid-latitude people get during a long, cold and grey winter wishing they could be closer to the equator).
Once the tropical cyclone reaches winds of at least 17 m/s (34 kt, 39 mph) they are typically called a "tropical storm" or in Australia a Category 1 cyclone and are assigned a name.
If winds reach 33 m/s (64 kt, 74 mph), then they are called:
"hurricane" (the North Atlantic Ocean, the Northeast Pacific Ocean east of the dateline, or the South Pacific Ocean east of 160E)
○"Typhoon" (the Northwest Pacific Ocean west of the dateline)
○"Severe tropical cyclone" or "Category 3 cyclone" and above (the Southwest Pacific Ocean west of 160°E or Southeast Indian Ocean east of 90°E)
○"Very severe cyclonic storm" (the North Indian Ocean)
○"Tropical cyclone" (the Southwest Indian Ocean)
