Weather and the Atmosphere Meteorology Study of atmosphere

Weather and the Atmosphere

• Meteorology– Study of atmosphere and the weather • Weather – Study of atmosphere at a given time and place, due to unequal heating of Earth’s surface

The Atmosphere

COMPOSITION OF TODAY’S ATMOSPHERE • • • 78 % Nitrogen 21 % Oxygen 0. 90 % Argon 0. 03 % Carbon Dioxide Traces of other gases, including water vapor (gas form of water)

Composition of the Atmosphere • ESRT Page 1

How Did The Atmosphere Form?

The Earth’s First Atmosphere To space Hydrogen Helium EARTH (roughly 4. 5 Billion years ago)

500 Million Years or So Later

OUTGASSING – release of methane, ammonia, Water Vapor, Carbon Dioxide and Nitrogen when the earth was cooling that made up Earth’s earlier atmosphere

Earth Cooled and Water Vapor Condensed to Form Oceans

• Most of the carbon dioxide dissolved in the newly formed oceans and … • then combined with other substances to form carboniferous sedimentary rocks (limestone and dolomite).

Nitrogen • Chemically inert • It remains in the atmosphere

Where did the oxygen come from?

CYANOBACTERIA – Found in Stromatolites

Cyanobacteria • Simple bacteria doing photosyntheses and releasing oxygen into the atmosphere • Over a billion years, the atmosphere began to change

Evidence • Banded Iron Formation – oxygen rusted iron in the sea, dates back 3. 5 billion years • Red Beds – rusted beds on land, dates back 2. 3 billion years

700 Million Years Later • With most of iron on Earth’s surface rusted… • …oxygen levels built up rapidly

A Few Million Years Later • Some of the oxygen was converted into Ozone (O 3) • a protective layer in stratosphere for life to develop on land

Evidence of increase in oxygen Earth Forms, H & He Atm. 4. 5 Banded Iron formations 4 Outgassing. Carbon Dioxide, Water Vapor & Nitrogen Formation Of Ozone Layer Red Bands 3 Cyanobacteria First appear – oxygen added to atm. 2 1 Now 78 % Nitrogen 21 % Oxygen 0. 90 Argon 0. 03 Carbon Dioxide Trace gases

Formation of Oceans • Large amounts of water vapor from early volcanoes eventually condensed • Condensation fell as rain which eventually formed our oceans • Comets may also have contributed to the water on the Earth

Layers of the Atmosphere • ESRT Page 14 Stratosphere – Ozone layer Troposphere – Where the weather happens

“pauses” • Where layers of atmosphere are separated. Temperature will change at the pauses (increase to decrease OR decrease to increase)

• http: //www. youtube. com/watch? v=Aka. Y 1 d v. Zer 4