Atmosphere The surrounding air of the Earth

Atmosphere: The thin envelope of gases surrounding the earth Highly compressible Density decreases rapidly with height Air: A mechanical mixture of gases and aerosols Definitions

Composition of Atmosphere Nitrogen - 78% Oxygen - 21% Water Vapor – 0 to 4% Carbon Dioxide -.037% Other gases make up the rest

Aerosols Solid: Ice/salt crystals, soil particles, volcanic dust Liquid: Water droplets (cloud, fog)

Origin of the Atmosphere Volcanoes release H 2, CO 2, H 2 O v, N 2, NH 3, CH 4 No O 2 or O 3, so no land organisms! One-celled aquatic organisms release CO 2 to atmosphere when breaking down food through fermentation Simple aquatic plants took in CO 2 and released O 2 to atmosphere via photosynthesis O 3 formed from the O 2

Layers of the atmosphere There are 4 layers in the atmosphere They are the troposphere, mesosphere, thermosphere, and stratosphere

Troposphere This is the layer that is closest to the surface of the earth It’s elevation ranges from 0 to 10 km Most of the mass of the atmosphere All of the water (vapor)

Stratosphere This layer sits on top of the troposphere It’s elevation ranges from 10 km to around 25 km This layer contains the ozone layer, which protects us from harmful sunlight

Stratosphere Also has temperature inversion. Temperature inversion: increase in temperature as altitude/height increases.

Mesosphere This layer is above the stratosphere It’s elevation ranges from 25 to 100 km Middle atmosphere – Air thin, pressure low, Need oxygen to live in this region. Air quite Cold -90°C (-130°F) near the top of mesosphere

Thermosphere “Hot” layer This is the highest layer of the atmosphere It’s height ranges from 100 to 400 km This is where most small meteorites burn up and is also the location in the atmosphere that the northern lights occur (aurora borealis) Sparse oxygen molecules absorb first solar energy rays

Clouds! (back to Troposphere) High-Level Clouds Cloud types include: cirrus and cirrostratus. Mid-Level Clouds Cloud types include: altocumulus, altostratus. Low-Level Clouds Cloud types include: nimbostratus, stratus and stratocumulus. Vertical Clouds Cumulus and Cumulonimbus

High Level Clouds Cirrus Clouds thin and wispy Cirrostratus Clouds sheet-like and nearly transparent

Mid-Level Clouds Altocumulus Clouds parallel bands or rounded masses Altostratus Clouds Puffy sheets

Low Level Clouds Nimbostratus Clouds dark, low-level clouds with precipitation Stratocumulus Clouds low, lumpy layer of clouds Stratus Clouds low, thick solid layer of gray cloud. Looks like fog.

Vertical Clouds Instead of covering a wide area, these clouds stretch high into the sky. Cumulus Cumulonimbus

Latin Defs. Latin RootTranslation cumulus stratus cirrus nimbus alto Cloud QuizCloud Quiz! heap layer curl of hair rain high