Atmospheric Composition and Structure

What is in the Atmosphere?

• The other gases include...

Neon Krypton Methane Helium Xenon Hydrogen Ozone

• The atmosphere is mostly air, which is a mixture of gases.

• There is also water vapor and small particles in the atmosphere.

Layers of the Atmosphere

Troposphere

Thermosphere

Stratosphere

Exosphere

Mesosphere

Key Facts: Troposphere• Lowest level of the atmosphere

– Experiences the highest air pressure. – Contains most of the atmosphere’s mass. – Most dense layer – Heated by the Earth through conduction.

• According to the temperature profile, as altitude increases, temperature decreases. – Allows for the creation of

convection currents.

The Troposphere is characterized by weather!

Key Facts: The Stratosphere

• According to the temperature profile, as altitude increases, temperature increases. – There is a temperature

inversion, which means warm air is on top of cold air!

– Air CANNOT rise because it is colder than its surroundings, and cold air sinks!!

Ozone Layer!

Key Facts: The Mesosphere• The mesosphere is colder because

the gases CANNOT absorb the sun’s radiation. – Continues through to the surface

where it is absorbed. – Top of this layer is somewhere

between -90°C and -100°C.

• The thermosphere contains gases that absorb the sun’s radiation. – Blocks the x-rays and some UV-

radiation. – The temperature depends on the

sun’s activity.

Factors that Affect Climate• Climate greatly affects

the species that exist in an ecosystem. – Climate is the average

weather of an area over a long period of time.

Temperature Precipitation

• Two main climate factors that influence life in an ecosystem are: