Topic 4 - Earth's Atmosphere - Composition and Structure

Atmosphere?

The envelope of gases that surrounds Earth

Meteorology?

Studies the atmosphere and everything in it

Weather?

Short term conditions of the atmosphere

Climate?

The long term conditions of the atmosphere

What is the atmosphere’s purpose?

the atmosphere insulates earth from extreme temperatures, provides oxygen for lifeforms, protects earth from sun’s radiation

What are the three criteria for studying the atmosphere?

function, composition, structure

What defines earth’s atmosphere?

a mixture of gases and water in three phases - liquid, solid, gas

What are permanent gases?

these gases have not changed since the atmosphere that we breathe formed

What is the composition of the atmosphere?

nitrogen, oxygen, argon and carbon dioxide

Which variable gases are important for our health and well being ?

water vapor, carbon dioxide, ozone and methane

Why is water vapor important ?

its the source of precipitation and its a good source of greenhouse gas

What does water vapor do ?

it traps heat energy in the atmosphere and keeps Earth’s air warm

How is carbon dioxide added to the atmosphere by natural causes?

forest fires, exhalation, volcanoes

How is carbon dioxide added to the atmosphere human caused?

mining, factories, burning of fossil fuels

How is carbon dioxide removed in only two natural ways?

photosynthesis and from the oceans absorbing carbon dioxide

What is photosynthesis?

plants absorb carbon dioxide and release oxygen

Why is carbon dioxide a problem?

traps outgoing thermal heat and blocks incoming thermal energy

What happens when there is too much carbon dioxide in the ocean?

can harm coral, seashells, fish scales and more

Why is ozone’s presence in the upper atmosphere essential to life on Earth?

It absorbs some solar radiation/uv radiation

Ozone is made up of ?

three Oxygen atoms bonded to form 1 molecule

Why is ozone dangerous on earths surface?

ozone has chemical and its irritant to lungs, eyes, nose

Where does methane come from?

comes from digestive gases - produced from decomposition of organic material

Why is methane more harmful?

it stays in the atmosphere for 10 years and is more harmful than CO2

What are aerosols?

tiny droplets or particles suspended in the air

What are some natural sources of aerosols?

salt spray, dust, fine sand, water

protons have what type of charge?

positive charge (+1)

neutrons have what type of charge?

neutral charge (0)

electrons have what type of charge?

negative charge (-1)

What is air pressure?

the weight of all of the air molecules pushing down on earths surface

As you rise in altitude or elevation …

air pressure decreases because there are fewer air molecules

What is altitude?

how high in the air (ex: plane, hot air balloon)

What is elevation?

feet are in the ground (ex: mountain)

How many layers are on earth’s atmosphere?

5 layers

What are the 5 layers in order from bottom to top?

troposphere, stratosphere, mesosphere, thermosphere, exosphere

What is the ozonosphere ?

its the ozone layer

Where is the Exosphere located and what is the temperature like?

last layer and the temperature is really cold

Where is the thermosphere located and what is the temperature like?

4th layer and temperature increases with altitude

Where is the mesosphere located and what is the temperature like?

middle layer, meteors burn in this layer and the temperature decreases with altitude

Where is the stratosphere located and what is the temperature like?

2nd layer, heating is caused by the ozone absorbing the uv radiation

In which layer of earth’s atmosphere is the ozone layer located?

stratosphere

Where is the troposphere located and what is the temperature like?

first layer, all of our weather occurs in this layer and the temperature decreases with altitude

What is the ionosphere?

it extends from the upper mesosphere into the thermosphere, it contains abundant positively charged ions and free electrons

what are the aurora borealis and aurora australis?

aka northern lights or southern lights

How do the aurora borealis form?

plasma from the sun gets caught in earths magnetic field, the gases of the air become energized and as the energy lessens the gases glow which causes the auroras

What is air pollution?

Anything that makes the air bad smelling, difficult to breathe and potentially unhealthy

What are some examples of natural pollution sources?

sulfur springs, decomposing vegetation, volcanic eruptions, aerosols etc

Why is Mt Pinatubo well known?

tons of ash into the air caused the air temperature to decrease a small amount

How does air pollution move about?

wind

What is anthropogenic pollution?

pollution caused by human activity

What are primary pollutants?

pollutants released directly into the air

What are secondary pollutants?

form when primary pollutants react with other chemicals in the atmosphere to form pollutants

What is photochemical smog ?

A type of air pollution that occurs when sunlight reacts with pollutants from auto exhaust creating a brown haze

What are the consequences of anthropogenic pollutants?

lung disease, acid rain, forest damage etc

What is the Clean Air Act?

It was enacted in 1970 and it limited the use of and emission of materials that cause air pollution

What were CFC’s doing to the ozone layer?

the CFS’s were eating the ozone layer, it was deteriorating

What is the Montreal Protocol?

in 1987 a major international treaty was set in motion to discontinue the use of CFC’s

In what year did the industrialized countries ban the use of CFC’s?

1996