Ozone Hole

Well dis time I'll bring u my assignment which is gonna be presented on 6th December. It is 4 my Environmental Protection class...besides I wanna build awareness among all of ya out there about dis serious problem...

Question 1: Why the Ozone Holes occur in Artarctica (South Pole)?

Not saying the Ozone Holes never occur anywherelse but why are they causing so much mess at South Pole?

As long as human first study in Antarctica, there is no such evidence penguins used hairspray, nor is air conditioning terribly popular among their kind. The question is, why isn't the ozone hole occur at some place where lots of air conditioner are being used?

The first reason, the earth's atmosphere is a giant gas-mixing machine. The earth spinning motion ensures all gasses released into air spread throughout the troposphere (lower atmosphere) over period of 1 year. Then, it takes 2-5 years to spread all over stratosphere (upper atmosphere). This should explain how CFC reached the South Pole.

The second reason, the climatological factors. Basically during the winter every year, there are 2 phenomena occur at the South Pole.

The Polar Vortex or Winter Vortex. A circulating winds in the middle lattitude over Antarctica. This phenomenon will isolates the air over Antarctica from the rest of the world's atmosphere.

The Polar Stratosphere Clouds (PSC). PSC formed at stratosphere which normally no clouds formed at this high level. Containing nitric-acid iced-crystal, this phenomenon turn out to concentrate the pollutant that break down the ozone layer.


Question 2: Why the Ozone Hole occur in Spring?

In winter, the earth's tilted axis prevent sunlight from shining on the South Pole. Causing the temperature to decrease to -70 degree C (-108 degree F)


Below are agents of ozone depletion. CFC is subjected to split its Cl atoms due to extreme cold and sunlight.

1)CFC compounds
2)Chlorine
3)Bromine

Cool air rising from the South Pole, creating Winter Vortex, as temperature continue to drop in the sunless winter, PSC begin to form over Antarctica.

Basic equation on Ozone issues:

CFC (subjected to UV)----------> CF3 + Cl

O3 (ozone) + Cl ----> ClO + O2

ClO + O3 --------> Cl + 2O2 (two molecules of oxygen)


Mostly, ClO will react with NO2 found in stratosphere naturally.

ClO + NO2 --------> ClNO3


Consequently preventing ClO from reacting with more O3 (ozone).

Unfortunately, PSCs' high concentration above Antarctica are catalyst for chemical reaction between ClNO3 and HCl.

ClNO3 + HCl (present of PSC) -------------> HNO3 + Cl2

Cl2 (sujected to UV) -----------> 2Cl (two chlorine atoms)



When spring comes, sunlight strike the clouds. The UV radiation splits the motherload of chlorine molecules into highly active chlorine atoms. Thus, provide more source of ozone depletion agents.


Bibliography:

http://www.coolantarctica.com/Antarctica%20fact%20file/science/ozone_hole.htm

http://ozonewatch.gsfc.nasa.gov/

http://www.wisegeek.com/why-is-the-hole-in-the-ozone-over-antarctica.htm

http://www.chemheritage.org/EducationalServices/FACES/env/readings/ant.htm



Haaa, thats all I can tell u...