TROPOSPHERE is the lowest LAYER of Earth’s atmosphere.It starts at the surface of the earth and goes up to a height of 7 to 20 km.All weather and seasonal variations occur within the troposphere.Stratosphere:-The stratosphere extends up to 50 km in height.The OZONE layer is found in the stratosphere layer.Mesosphere:-It starts at 50 km above the surface of Earth and goes up to 85 km.The mesosphere is the coldest of the atmospheric layers.Thermosphere:-It is found from 80 to 400 km.Aurora and satellites occur in Thermosphere.Exosphere:-The exosphere is the outermost layer of the atmosphere.The exosphere extends from the TOP of the thermosphere up to 10000 km.