Introduction to the Structure of Earths Atmosphere

Terms• Atmosphere-The gases, droplets, and particles

surrounding Earth’s surface.• Weather-Day to Day conditions of the

atmosphere.• Climate-The statistical properties of the

atmosphere, including measures of average conditions, variability, etc.

• Climatology-The study of long term atmospheric conditions.

FACT

-The total mass of the atmosphere is equivelant to 5.65 billion million tons.

Levels of atmosphere• Troposphere• Stratosphere• Mesosphere• Thermosphere• Exosphere

Vertical Structure• Troposphere-• Lowest layer of the atmosphere. Where almost

all weather and organisms take place. Decreasing temperatures. Depth= 8 to 16km(3.6 to 10 miles).

• It contains 70% of all mass of atmosphere. The density of troposphere is decreases with altitude. This decreases of temperature with altitude is known as Lapse rate.

Vertical Structure CONT.• Stratosphere-• Second lowest layer of atmosphere. It extend

about 50-55 km above the surface of the earth.• Ozone layer is found at around 20 km from

ground is called Ozonosphere and act as a protective layer against harmful ultraviolet radiations.

• Temperature increases with altitude.(positive lapse rate)

Vertical Structure CONT.• Mesosphere- • Third layer in the atmosphere. Decreasing

temperature with altitude(negative lapse rate). Depth=Approx. 80km(50 miles).

• This layer is very special as all sound waves as well as short radio waves coming from earth re reflected from this layer.

Vertical Structure CONT.• Thermosphere-• The upper layer from mesosphere in

atmosphere. Increasing temperature with altitude. Depth=Begins at 80km to 500km.

• Ionisation of elements like oxygen and nitric oxide take place in the upper most portion of sphere is called the Ionosphere.

Vertical Structure CONT.• Exosphere-• The upper most layer of the atmosphere is

known as exosphere. It extend up to a height of 1600km from the surface of earth.

• The temperature of this layer is more than 1200 °C is Found.

ADDITIONS• Tropopause-• The tropopause is the boundary in the Earth's

atmosphere between troposphere and stratosphere. Transition zone where the temperature ceases to decrease.

• Stratopause-• Top of stratosphere, the temperature increases

with altitude, and the stratopause is the region where a maximum in the temperature occurs.

ADDITIONS CONT.• Mesopause- • The mesopause is the boundary between

the mesosphere and the thermosphere. Due to the lack of solar heating and very strong radioactive cooling from carbon dioxide, the mesosphere is the coldest region on Earth with temperatures as low as -100 °C.

http://burro.cwru.edu/Academics/Astr201/Atmosphere/structure.jpg

Relevant Terms• Homosphere-• The lowest 80km of the atmosphere, which

the relative abundance of the permanent gases is constant.

• Heterosphere-• The high atmosphere where gases are not well

mixed but rather are stratified according to weight. Where lighter weighing gases are found.

The End