Earth's Climate

Question 1

What are the 4 layers of the atmosphere and how are they separated?

Answer 1

1. Troposphere (0 - 10km) (80% mass of the atmosphere) (16 to -55°C)
2. Stratosphere (10 - 50km) (20% mass) (-50 to 0°C)
3. Mesosphere (50 - 85km) (0 to -90°C)
4. Thermosphere (85 - 600km) (-90 to 1500°C)

The atmospheric layers are separated by temperature.

Question 2

What is the composition of the dry atmosphere?

Answer 2

Nitrogen - 800,000 ppmv (78%)
Oxygen - 200,000 ppmv (21%)
Argon - 10,000 ppmv (0.9%)
Carbon Dioxide and other gases - 400 ppmv (0.05%)

Same throughout the layers.

Question 3

What are the noble gases in the atmosphere?

ANHKX

Answer 3

Argon (most abundant)
Neon
Helium
Krypton
Xenon (least abundant)

Question 4

What are the important greenhouse gases in the atmosphere?

Answer 4

1. Water vapour (most abundant) - does not stay in the atmosphere for long. After a few days, will condense and precipitate as rain and snow.
2. Carbon dioxide (most important, come from humans)
3. Methane - strongest greenhouse effect
4. Nitrous oxide
5. Ozone
6. Nitrous dioxide

Question 5

What are the signs that global warming is happening?

Answer 5

1. Atmospheric CO2 concentration has been increasing ~0.5%/yr from emissions (noted in the Keeling Curve)
2. Stratospheric H2O concentration is increasing ~1%/yr
   from H2O transport from the troposphere (strong uplifting/convection, indicating higher temperature) and methane transport (oxidise with oxygen to form H2O)
3. Temperate is increasing in troposphere BUT decreasing in the stratosphere. Strongly suggests that climate change is caused by human activity on Earth.

Question 6

Who are the most famous scientific giants in Climate Change?

Answer 6

1. Svante Arrhenius - greenhouse effect and CO2
2. Charles Keeling - progressive build-up of CO2
3. Wallace Broecker - carbon cycle