Earth’s Atmosphere intro intro

Atmospheric Composition Gas% Nitrogen78% Oxygen21% Argon0.9% Carbon Dioxide0.04% Other Gases, Dust and Water Vapor 0.06%

Earth’s Unique Atmosphere 1. Magnetic Field: a layer of electrical charge that protects Earth by deflecting solar winds and cosmic rays The magnetic field is caused by the liquid metal in earth’s outer core

Ozone Layer 2. Ozone Layer: a layer of ozone (Oз) molecules that reflects UV radiation

Ozone Layer Good ozone: found in the stratosphere and reflects harmful UV radiation

Ozone Bad Ozone: found in the troposphere and causes air pollution and harms lung tissue

Ozone Depletion Ozone Depletion: Humans are releasing CFC gases into the atmosphere that destroy ozone molecules

CFC’s CFC’s: Chlorofluorocarbons: gases that break up ozone molecules in earth’s atmosphere New Regulations: Montreal Protocol (1987): Now products are made with little or no CFC gases to protect our ozone layer

Earth’s Unique Atmosphere 3. Greenhouse Effect: Greenhouse gases trap heat inside Earth’s atmosphere and reflect heat back to Earth’s surface

Greenhouse Gases Greenhouse gas: any gas that traps heat inside Earth’s atmosphere Examples of greenhouse gases are: – Carbon dioxide: CO₂ – Methane: CH ₄ – Water Vapor: H₂O – Nitrous oxide: N₂O – Sulfur Dioxide: SO₂

Carbon dioxide Carbon dioxide is a greenhouse gas that scientists think could be contributing to a change in earth’s climate

Layers of the Atmosphere Exosphere Thermosphere Mesosphere Stratosphere Troposphere

Exosphere miles above earth’s surface Temperature increases with altitude This is the hottest layer = 2000 ⁰F Mostly just hydrogen and helium from solar winds here The beginning edge of space

Thermosphere miles above earth’s surface Temperature increases with altitude The space shuttle, space station and satellites orbit here Auroras form here Aurora: a light display caused by energetic particles interacting with earth’s magnetic field

Mesosphere miles above earth’s surface Temperature decreases with altitude The coldest layer = -130 ⁰F Meteors burn up here Noctilucent clouds: clouds made of ice crystals form in this layer

Stratosphere 6-30 miles above Earth’s surface Temperature increases with altitude Good ozone layer found here Military planes and jets fly here – “Military space” The Jet Stream is found here Weather balloons (radiosondes) reach this layer

Troposphere 0-6 miles above earth’s surface Temperature decreases with altitude Contains the most air molecules = highest air pressure Bad ozone = pollution and lung tissue damage Weather and clouds form here Commercial airplanes fly here The highest mountain = Mount Everest (5.5 miles)

Earth’s Energy Budget earth's energy budget Solar radiation: energy coming from the sun in the form of electromagnetic waves

Earth’s Energy Budget 6% of solar radiation is reflected by the atmosphere 20% of solar radiation is reflected by the clouds 4% of solar radiation is reflected by the surface 19%of solar radiation is absorbed by the atmosphere and clouds 51% of solar radiation is absorbed by the surface

Earth’s Energy Budget What happens to MOST of the incoming solar radiation from the Sun?

??Critical Thinking Question?? How would life on earth be different if the atmosphere did not absorb or reflect any incoming radiation from the sun?

Albedo Albedo: the amount of solar radiation reflected off of an object How much radiation is reflected depends on the color, texture, composition, volume and state of matter of the object

Albedo High albedo: snow, water, clouds Low albedo: soil, forest, asphalt

Atmospheric Conduction Conduction: the transfer of heat through physical touch Earth’s surface gets heated by solar radiation Then air molecules that touch earth’s surface get heated through atmospheric conduction

Atmospheric Convection Convection: the transfer of heat through the movement of a fluid Hot air rises and cold air sinks creating atmospheric circulation and global wind patterns

Three ways to transfer heat Conduction Convection radiation

Popcorn

Lizard on a Rock Exit Ticket: How is this lizard getting heat energy transferred to it? Use the terms radiation, conduction and convection in your answer and write in complete sentences

Protect the Penguin Activity Radiation from the sun heats the lizard and the rock. Conduction from the hot rock heats the lizard Convection from the warm air circulating around the lizard heats the lizard