The Atmosphere Objectives 1 Describe the composition of

The Atmosphere Objectives: 1. Describe the composition of the Earth’s atmosphere 2. Describe the layers of the Earth’s atmosphere. 3. Explain three mechanisms of heat transfer in the atmosphere. 4. Explain the greenhouse effect.

The Atmosphere n n n One of the four parts that make up the Earth. Atmosphere – the mixture of gases surrounding the Earth. The atmosphere insulates the Earth.

The Composition of the Atmosphere n Made mainly of nitrogen, oxygen, carbon dioxide and dust. n The amounts of gases changes due to n Animals n Plants n Vehicles n Volcanoes - nitrogen

The Four Layers of the Atmosphere 1. Troposphere – *closest to surface *from 0 -18 km (11 miles) up *densest layer *planes fly at about 9 km (6 miles) *weather occurs here *the higher you go, the colder ( -50 F) and less oxygenated the air is. n Highest place on Earth - Mt. Everest in the Himalayan Mountains (about 9 km or 5 miles high) n http: //www. youtube. co m/watch? v=CNTy. L 6 ua pj. M

The Four Layers of the Atmosphere 2. Stratosphere *from 18 - 50 km (11 to 30 miles) up *temperature is warmer than the troposphere because the ozone layer is located here. Bottom = -50 F Top = -15 F *Felix Baumgartner spacedived from the stratosphere (24 miles up) in October of 2012. http: //www. redbullstratos. com/ gallery/videos/all-tags/1

The Four Layers of the Atmosphere 3. Mesosphere *from 50 -80 km (30 to 50 miles) up *temperature is the coldest of all the layers (-90 F) *meteors entering the atmosphere vaporize in this layer

The Four Layers of the Atmosphere 4. Thermosphere *from 80 - 550 km (50 to 350 miles) up *temperature is the warmest of all the layers (3600 F) *space shuttles orbit here

Energy in the Atmosphere n Energy from the sun moves through the atmosphere in three ways: n n n Radiation Conduction Convection

Energy in the Atmosphere n Radiation – the transfer of energy across space n n n From the fire to the pan From the sun to the earth When you stand in front of a fire and feel warm

Energy in the Atmosphere n Conduction – flow of heat from a warmer object to a colder object when they are touching n n Your hand feels warm when touching the pot handle Warming your hands with a hot cup of coffee

Energy in the Atmosphere n Convection – the transfer of heat that occurs when hot air rises and cold air sinks. n n n The “rolling” of boiling water Heat waves rising from the sidewalk Steam rising from a hot drink A lava lamp Weather

Energy in the Atmosphere

The Greenhouse Effect n n n Gases such as carbon dioxide, methane and water vapor in the atmosphere the Sun’s energy and heat the earth. If this didn’t happen, the earth would be too cold for life. When we add carbon dioxide to the atmosphere through pollution, the atmosphere traps more heat than normal and temperatures rise!

The Greenhouse Effect n Other examples of the greenhouse effect n n A greenhouse The inside of a car on a sunny day