The Atmosphere
WALT: about the Earth‘s Atmosphere
The Atmosphere: Die Atmosphäre
• The Earth‘s atmosphere is a thin layer of gases that surround the Earth.
• The layer of gas stays there due to gravity.
• The atmosphere has
several important jobs;
The Atmosphere: Die Atmosphäre
• The atmosphere has several important jobs;
– It insulates the Earth from extreme temperatures.
– It keeps heat inside the atmosphere.
– It blocks harmful radiation
from the sun.
The Atmosphere: Die Atmosphäre
• The atmosphere has a mass of about 5 quintillion kg.
• Three quarters of which is within the first 11km.
• The atmosphere becomes thinner the higher up you go.
• At 100 – 120 km up is roughly the boundry
between our atmosphere
and outerspace.
7 – 17 km
The weather and clouds occur in this part.
Temperature decreases as you go up.
17 – 50 km
Temperature increases as you go up.
Ozone layer is at about 25km
50 – 80 km
Temperature decreases quickly as you go up.
Meteors
ATMOSPHERESPACE
85 – 650 km
Temperatures increase as you go up to 1,500ºC Space station orbits at 350 km
650 - 10,000 km
Particles very spread out Mainly hydrogen and helium
Atmosphere quiz
1. What is the name of the layer of the
atmosphere that is closest to the earth?
2. In which layer does the space station orbit.
3. Why do we need the atmosphere (4 reasons)?
4. What was the most interesting thing you
learn today?
26/01/22
4 Billion years 3 Billion years 2 Billion years 1 Billion years Present day
Evolution of the Earth’s Atmosphere
Volcanic activity
releases CO
2, methane, ammonia and water
vapour into the
atmosphere. The water vapour condenses to
form oceans.
Some of the oxygen is converted into ozone.
The ozone layer blocks out harmful ultra-violet rays which allows for the
development of new life.
Green plants evolve which take in CO
2and give out oxygen. Carbon from CO
2becomes locked up in sedimentary rocks as carbonates and fossil fuels. Methane and ammonia react with the oxygen and
nitrogen is released. Nitrogen is also produced as a result of denitrifying
bacteria on nitrates from decaying plants.
26/01/22
4 Billion years 3 Billion years 2 Billion years 1 Billion years Present day
Evolution of the Earth’s Atmosphere
Carbon dioxide
Methane Ammonia Oxygen Nitrogen Others
Present day
atmosphere contains 78% nitrogen, 21%
oxygen, 1% noble
gases and about
0.03% CO
2The Ozone Layer
• Ozone is oxygen that contains molecules that have 3 oxygen atoms (O3).
• There is a layer of ozone high up in the atmosphere which shields the Earth from the sun's harmful UV rays, these rays can lead to an increase in skin cancer.
• In the 1980’s concentrations of ozone appeared to be dropping in certain areas of the world.
• The map below show the concentrations of ozone over the northern hemisphere 1980-1991:-
Air Pressure: Luftdruck
• Air pressure is the force exerted on you by the weight of tiny particles of air.
• Air pressure at sea level is equivalent to a force of 1kg per cm² .
Sea Level 1000 hPa
Zugspitze 3000m 700 hPa
Everest 8800m 350 hPa
Air pressure
• This plastic bottle, sealed at
approximately 2,000 m altitude, was crushed by the increase in
atmospheric pressure
when brought to sea
level.
Air Pressure
• We live at the bottom of an ocean -- an ocean of air. This air presses on everything, and we call that AIR
PRESSURE.
• Bernoulli discovered that air doesn't press as hard when
it's moving. The faster it moves, the less it presses.
Helicopters Air
Resistance
Bikes, cars and other vehicles experience air resistance as they move. Air resistance is caused by the frictional forces of the air
against the vehicle. The faster the vehicle moves, the bigger the air resistance becomes. The top speed of a vehicle is reached when the force from the cyclist or engine is balanced by air resistance.
