Lecture 1-Earth System Flashcards
List the three most abundant gases of the atmosphere by volume.
Nitrogen 78.08%
Oxygen 20.95%
Argon 0.93%
Name the 5 gases that surround the Earth.
Nitrogen Oxygen Argon H2O water vapor Carbon dioxide
What does the Hydrosphere contain?
All the Earth’s oceans, lakes, underground water, ice and snow
What does the Geosphere contain?
The solid earth (rocks and regolith)
What does the Biosphere contain?
All the Earth’s organisms and organic matter that has not yet decomposed
What does the Anthropsphere contain?
The part that has been made or modified by human beings
What is the definition of the atmosphere?
A gaseous envelope that surrounds a planet or other celestial body
What is air?
Air is a mixture of gases and suspended particles that surrounds the Earth
Why is the atmosphere important?
It affects the Earth’s surface temperature (greenhouse effect) because of the presence of gases like water vapor and carbon dioxide
It also allows us to breathe and ozone protects the Earth by absorbing UV rays
What is Meteorology?
The study of the atmosphere and its phenomena
What are aerosols?
Tiny liquid droplets or tiny particles that are so small they remain suspended in the air
Name 5 examples of aerosols
Smoke Volcanic ash Dust Ocean spray (sea salt crystals) Ice crystals
What affect do aerosols have on climate?
Some aerosols directly absorb radiation. Soot from industrial pollution for example heats the atmosphere
Other aerosols reflect incoming radiation such as sulfur which provides a cooling effect
Describe the Earth’s first atmosphere
It was primarily composed of Helium and Hydrogen however did not last very long as they were both extremely light gases. At the time Earth’s gravity was too weak to hold such a light compound and its magnetic field was not strong enough to protect the developing atmosphere from solar winds.
How was Earth’s second atmosphere created?
Volcanic eruptions pushed out water vapor, carbon dioxide and nitrogen.
Water vapor formed oceans, carbon dioxide went into oceans and rocks
Comets and their icy bodies came crashing into the Earth
Photosynthesis increased oxygen in the air and as a result produced ozone in the upper atmosphere which enabled plant and animal life to evolve
Describe Nitrogen.
Nitrogen is 78.08% dry volume of air.
Removed from the atmosphere by soil bacteria
Returned to atmosphere through animal/plant decay
Describe Oxygen.
Oxygen holds 20.95% of dry air volume.
Removed from atmosphere when organic matter decays
Returned to atmosphere through photosynthesis
Taken from atmosphere through breathing, lungs release carbon dioxide
Describe Water vapor.
Most abundant variable gas
Supplied through evaporation
Removed from atmosphere through condensation
Concentration reaches maximum in tropics and decreases rapidly with higher altitudes
It is a greenhouse gas that absorbs thermal energy and releases latent heat to fuel weather systems
Describe Carbon Dioxide
Holds concentration of 385 ppm
Created/input by volcanic eruptions, burning fossil fuels, decay/combustion of biomass
Output/sink: photosynthesis (plants consume carbon dioxide to produce green matter)
Phytoplankton fix carbon dioxide into organic tissues
What is the greenhouse effect?
The greenhouse effect is the process by which the earth absorbs infrared radiation through water vapor, carbon dioxide and other related gases
Increase in carbon dioxide is believed to be the primary cause of global warming as it traps the earths outgoing energy
Describe Methane
Holds a concentration of 1.75 ppm
Comes mainly from breakdown of plants by methogenic bacteria
Low oxygen soil
Termite activity
Describe Nitrous oxide
Holds a concentration of 0.3 ppm
Produced by natural and human sources
Formed in soils by denitrifying bacteria and fossil fuel combustion
Destroyed by ultra violet rays
Describe Chlorofluorocarbons
Holds concentration of 0.0002 ppm
Used to be found mostly in propellants and sprays
Plays a role in destruction of oZone
Uv rays breaks it apart and destroys ozone by production of chlorine
How can the structure of the atmosphere be characterized?
Pressure
Density
Temperature
Composition
Describe atmospheric density
It is the concentration of molecules
Atmospheric density decreases with altitude
How do you calculate the atmospheric density?
Density = mass/volume
p=m/v
Describe Pressure
It is the force exerted on a given area
Air pressure occurs when air molecules move and collide with objects
It is exerted in a directions
How do you calculate pressure?
Pressure = force/area
What is the average sea level pressure?
1013.25 millibars
Name the four atmospheric layers
Troposphere- temperature decreases with height
Stratosphere- temp increases with height
Mesosphere - temp decreases with height
Thermosphere - temp increases with height
What is the lapse rate?
The rate at which air temp decreases with height.
T = temperature z = height
Describe the troposphere
Average lapse rate of ~6.5 C/km
Goes up to 12km
Weather occurs here
Describe stratosphere
Ranges from 12 to 50 km
Air is very and oZone rich
Temp maximum goes to stratopause
Describe mesosphere
Ranges from 50 to 85 km
Extremely thin air, atmospheric pressure averaging 1 millibar
Lowest temperature found here -85C
Describe exosphere
Above 500 km
Above thermosphere level
Region where atoms and molecules shoot into space
Describe thermosphere
Highest temperatures found here due to absorption of high energy radiation
Temperature increase due to photodisassociation and photoionization
What does the homosphere contain
Troposphere
Stratosphere
Mesosphere
What does the heterosphere contain
Thermosphere
Exosphere
List the four spheres of the Earth.
Atmosphere Biosphere Hydrosphere Geosphere Anthropsphere
