What is the ATMOSPHERE?

The Atmosphere The layer of gases (AIR) that surrounds the earth. It stretches more than 400 km above us. Today, we’re going to explore it!

VIDEO https://www.youtube.com/watch?v=5sg9sCOXFIk

TROPOSPHERE Shortest Layer (0-12 km) Average Temperature of 25°C (Temperature drops as you go higher) All of Earth’s weather happens here. Air here contains water & dust. Most of the atmosphere’s air is here (this layer is very dense).

STRATOSPHERE 12-50 km above earth’s surface Very cold, until the top of the layer, where it warms to 0°C. There is no water or dust in this layer. Contains the OZONE LAYER (which absorbs UV radiation from the sun) Air is less dense than troposphere.

MESOSPHERE 50-80 km above Earth’s surface. Temperature plunges to -90°C (the coldest in the atmosphere) Meteors burn up here while entering the atmosphere. Air is thinner here.

THERMOSPHERE Largest layer (80-400 km above Earth’s surface). Air is extremely thin. Atmospheric gases fade into outer space. Satellites and shuttles orbit here. Temperature can spike to 1,800°C.

Challenge! Make a MNEMONIC! Example: Tonight, Snakes Make Tea Everywhere Troposhere, Sratusphere, Mesosphere, Thermosphere, Exosphere

Definitions Density Air Pressure Altitude how compact a substance is how much force exerted on an object by the weight of the air Low pressure brings RAIN! Altitude the height of an object

Relationship! Altitude and Air Pressure At higher altitudes, less air means less weight and less pressure.