Layers of the Atmosphere

Layers of the Atmosphere The layers of our atmosphere are based on temperature changes. The Troposphere: The Layer in Which We Live The lowest layer of the atmosphere, which lies next to the Earth’s surface, is called the troposphere. The Stratosphere: Home of the Ozone Layer The atmospheric layer above the troposphere is called the stratosphere. The Mesosphere: The Middle Layer The mesosphere is the middle layer of the atmosphere. It is also the coldest layer.

Layers of the Atmosphere, continued The Thermosphere: The Edge of the Atmosphere The uppermost atmospheric layer is called the thermosphere. The Ionosphere: Home of the Auroras In the upper mesosphere and the lower thermosphere, nitrogen and oxygen atoms absorb harmful solar energy. This area is called the ionosphere.

Temperature and the Troposphere Troposphere: temperature at surface is warmed by the earth absorbing energy from the sun. Convection currents carry the heat upward, so the air cools as it rises. The air cools by about 6.5°C for every 1-km above the ground.

Temperature and the Stratosphere Ozone absorbs ultraviolet radiation from the sun, causing the temperature to increase.

Temperature and the Mesosphere This layer does not absorb energy from the sun, so it starts to cool again.

Temperature and the Thermosphere Solar radiation first hits this layer, so the few particles that are here can gain lots of energy. They move rapidly, so they have a very high temperature. But the air is so thin here that it takes special instruments to measure the temperature accurately.

The Troposphere Lowest (inner) layer weather occurs here we live in it. “tropo” means turning or changing conditions depth varies from 9km above the poles to 16km at the equator shallowest (least thick) layer, but contains most of the mass. Heated by convection currents

The Stratosphere “strato” means layer or spreading out Contains the ozone layer which absorbs energy and causes the temperature to rise The ozone layer protects the surface from dangerous UV rays Jet stream

The Mesosphere Drop in temperature marks beginning of mesosphere “Meso” means middle Most meteors burn up here Coldest layer

The Thermosphere Very top layer Air is very, very thin, about 1/1000th as dense as the air at sea level “Thermo” means heat Extends from 80km to space No definite outer edge Very hot (1800°C), but since air is so thin it would not feel warm at all. Divided into two parts, the ionosphere and the exosphere

The Ionosphere Energy from sun strips the electrons from the gas molecules creating charged particles called ions. Radio waves can bounce off of ions, allowing radio waves to travel great distances. The aurora borealis (Northern Lights) occur here

The Exosphere “Exo” means outer Extends for 1000’s of miles Satellites orbit here No definite edge