Aim: How does the Atmosphere on Earth support life? Do Now: In your notes, describe what you think the atmosphere does for us?

I. Atmosphere (atm) Composition Made up of 4 layers (troposphere, stratosphere, mesosphere and thermosphere) Nitrogen and Oxygen make up 99% of the. Gases in the atmosphere today: Page 1 ESRT

A. Water Vapor: oceans are the source most important gas in the atmosphere. absorbs heat (from earth & sun) makes the air lighter (less dense) What is the primary source of water vapor in the atmosphere? Altitude (km) Describe the relationship seen in the graph. ESRT p.14

B. Dust Particles: - any solid that can float in the air ( dust, salt, ash, organics) - helps make clouds - In large quantities, these particles could block out the heat and light from the sun. What might be an effect of blocking out light and heat from the sun? Has this happened before? Mt. St. Helens Eruption, 1980

Mt. St. Helens Eruption Washington, 1980 Mt. Eyjafjallajökull Eruption Iceland, 2010

C. Ozone: (O 3 ) - found in the stratosphere. - poisonous to people. - filters harmful ultra-violet rays (UV) from the sun. - depleted (destroyed) by CFC’s (chloroflorocarbons). These are found in aerosol cans and refrigerants.

Someone said there is a hole in the Ozone Each year for the past few decades during the Southern Hemisphere spring (our Fall), ozone in the southern polar region is destroyed rapidly and severely. This depleted region is known as the “ozone hole”. Ozone measurement for March 30 th 2014 Ozone measurement for September 2013

II. Human Influence on the Atmosphere: - Emissions from cars and factories account for nearly half the pollutants by weight in the atmosphere. Where does the other half come from?

III. Atmosphere and Temperature - Perfect distance from the sun! - Water vapor and CO2 in the atmosphere traps heat and keeps our planet warm. 150 million kilometers

Closure: