EI NINO EFFECT:- In tropical pacific ocean,  temp.  of water increases very sharply upto 80^oC and causes mortality in aquatic organism over 1000km, it is hot water current flowing from equator to pole, It regulates  the monsoon effect.

La Nino Effect:- It is reverse of EL NINO effect. It is called Water current flow from pole to equator. It also causes mortality in aquatic animal and occurs periodically.

• Good ozone is found in stratosphere while Bad Ozone is found in troposphere.

Because ozone in troposphere behaves as pollutant. Thickness of ozone layer is measured in Dobson Unit (DU).

• Depletion in Ozone layer is called Ozone hole. Ozone hole appear in south pole during late august and early October in antartica .
• CFC’s, freons and jet planes are responsible for depletion in Ozone layer.
• CFC’s react with ozone to form oxygen gas and nascent oxygen.