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Date: 26 Aug 2010 23:01:00
Title: The ITCZ

Inter-Tropical Convergence Zone

 

 

 

 

 

Too many books can make this a complicated subject to understand so basically the Inter-Tropical Convergence Zone (ITCZ) appears as a band of clouds consisting of showers, with occasional thunderstorms, that encircles the globe near the equator. The solid band of clouds may extend for many hundreds of miles and is sometimes broken into smaller line segments. The ITCZ follows the sun in that the position varies seasonally. It moves north in the northern summer and south in the northern winter. The ITCZ (pronounced "itch") is what is responsible for the wet and dry seasons in the tropics. It exists because of the convergence of the trade winds. In the northern hemisphere the trade winds move in a southwesterly direction, while in the southern hemisphere they move northwesterly. The point at which the trade winds converge forces the air up into the atmosphere, forming the ITCZ.

 

 

The tendency for convective storms in the tropics is to be short in their duration, usually on a small scale but can produce intense rainfall. It is estimated that forty percent of all tropical rainfall rates exceed one inch per hour. Greatest rainfall typically occurs when the midday sun is overhead. On the equator this occurs twice a year in March and September, and consequently there are two wet and two dry seasons. Further away from the equator, the two rainy seasons merge into one, and the climate becomes more monsoonal, with one wet season and one dry season. In the Northern Hemisphere, the wet season occurs from May to July, in the Southern Hemisphere from November to February.

 

 

Across the road behind us is a rain forest and hills that have a local effect on producing afternoon thundershowers and being in the wet season, not too many days go by without a lunch time wetting. The ITCZ can is either give us an umbrella effect that protects us from the local weather OR it absolutely hammers down compounding what we already have. The ITCZ this season is sitting over us quite a lot of the time. Last August it rained a total of three hundred and thirty three millimeters for the whole month. The first week of August this year produced two hundred and six millimeters alone, causing landslides, floods, loss of a life and caused many people to lose everything, especially in the south of Trinidad. The Caroni River burst its banks and there was a evacuation emergency in place.

 

We played a lot of Backgammon and for the first time ever, since we began playing, Bear got ahead. Let the sun come out and let me get back on top……………..

 

 

 ALL IN ALL THE ITCZ CAN BE AN ITCH ALRIGHT


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