Structure Of The Atmosphere Flashcards
What is the atmosphere
Mixture of gases surrounding the Earth
Mesosphere
Layer of the atmosphere above the stratosphere to an altitude of about 80km above the surface of the earth
Stratosphere
Layer of the atmosphere above the troposphere in which the temperature does not decrease with increasing altitude
Thermosphere
Outermost layer of the earths atmosphere (to approximately 100km from the Earth’s surface), where the temperature falls with increasing altitude
Tropopause
The boundary or interface between the troposphere and the stratosphere
Troposphere
The layer of atmosphere extending approximately 8-17km upwards from the earths surface, in which temperature decreases with increasing height
What does the atmosphere consist of
78% nitrogen
21% oxygen
Where is the top of the atmosphere assumed to be
1,000km
Due to gravity and compression..
Most of the atmosphere is concentrated near to the earths surface
Where does 99% of the atmosphere lie
Within 40km
What is the most important part of the atmosphere in the study of weather and climate
Troposphere
Where does most of our weather and climate processes operate
Within 16-17km of the earths surface in this lower atmospheric zone (troposphere)
Temperatures in the troposphere
Generally decrease with height
6.5 •c per km
Where is the troposphere found
Height of 7km at poles and 17km in tropics (vary with seasonal changes in climate)
What does the troposphere act as
A temperature inversion, forming an effective ceiling to convection in the troposphere- so provides an upper limit to the earths weather systems
How is the atmosphere disturbed in the troposphere
Vertical convection currents disturb the atmosphere and air masses flow horizontally from one latitude to another
Characteristics of the stratosphere
Extends to 50km
Free of cloud and dust
Absorbs ultraviolet radiation
Where is warming greater
Over polar regions- these temperature differences cause strong horizontal air movements at great heights
What has global warming been linked to
Recent changes in the stratosphere, bought about by human activity
Temperatures within the mesosphere
Temperatures decrease with altitude
Temperatures within the thermosphere
Temperatures rise again at a constant rate to as much as 1,500•c
