Por: Pavan Kulkarni

Data: 30 de Maio

Hora: 14:30
Local: Anfiteatro 1 - CLAV

Abstract:

Ozone is present in the atmosphere from surface to top of the atmosphere (~80 km).About 85-90% of the ozone in our atmosphere is contained in the stratosphere, theregion from about 10 to 50-km above Earth's surface. 10-15% of the ozone is containedin the troposphere, the lowest part of our atmosphere (surface to 8-15km, depending onlatitude) where all of our weather takes place. Small amount of ozone is contained in themesosphere, the region from about 50 to 80km.Breathing ozone is lethal at dosage levels of a few molecules per million air moleculesfor flora and fauna. It is highly corrosive in nature. This is why ozone at the surface isreferred to as a pollutant. Yet ozone high in the atmosphere screens out biologicallyharmful solar ultraviolet radiation, responsible for destructive alteration of geneticcellular material in plants and animals, as well as human beings. Without the "ozonelayer" high up in the atmosphere, life on the surface of the Earth would not be possibleas we know it.Human activities over the centuries have affected the natural balance of Ozonein our atmosphere. Depletion of stratospheric “good” ozone and increase in freetropospheric as well as surface “bad” ozone are of concern for both environmental andclimate change prospective. Therefore understanding the spatial-temporal variation,photophysics and photochemistry of ozone is very important.