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[clever angel]

hi
i seriously have no idea what to write for this dotpoint: analyse the information availabe that indicates changes in atmospheric ozone concentrations , decribe the changes obsevred and explain how the ifnromaiton was obtained


plzz help asap

thanks in advance!!

 

[LSP]

In the late 1980s, the TOMS (Total Ozone Mapping Spectrometer) aboard the Nimbus-7 satellite recorded significant thinning of the ozone layer over Antarctica, evidence led to the acceptance of the theory that CFCs and the chlorine radicals they produce led to the decline of the ozone layer. Since then, very large decreases (known as ‘holes’) have been observed by TOMS.

There is an increase in ozone thinning during spring in Antarctica after a long winter, because ice crystal surfaces help generate molecular chlorine by the reaction of HCl and ClONO2. The Cl2 photodissociates with the extra UV radiation in spring to produce more chlorine free radicals that increases ozone depletion. By summer the Cl2 levels have depleted and ozone concentrations return to normal levels.

The information about ozone concentrations are collected by TOMS on satellites, spectrometers on scientific balloons and ground-based spectrometers.

Basically, setellite(TOMS) shows the oxygen level changes in the atmosphere. u will find some images in ur text book. and note where and when is oxygen concentration low at most.

Hope this helps