Chapter 1C: Vertical Structure of the Atmosphere & Temperature and Atmospheric Layers

Question 1

Why are there different layers in the atmosphere?

Answer 1

The atmosphere is divided into layers that correspond to different parts of its temperature profile.

Question 2

What is the lapse rate? (in general)

Answer 2

The lapse rate describes change in temperature with a change in height.
It is described by γ = -ΔT/Δz (°C /km)

Question 3

What does it mean when a lapse rate is positive?

Answer 3

A positive lapse rate means that the temperature decreases with increasing height.

Question 4

What does it mean when a lapse rate is negative?

Answer 4

A negative lapse rate means that there is a temperature inversion; that temperature increases with increasing height.

Question 5

What is an isothermal environment?

Answer 5

An isothermal environment implies no change in temperature with height; the lapse rate is 0°C /km.

Question 6

Give an example of where there is an isothermal environment.

Answer 6

From the troposphere to the stratosphere.
From the stratosphere to the mesosphere.
From the mesosphere to the thermosphere.

(An isothermal environment implies no change in temperature with height; the lapse rate is 0°C /km.)

Question 7

What is a temperature inversion?

Answer 7

A temperature inversion is when temperature increases with increasing height; in this case, the lapse rate is negative.

Question 8

Place the layers of the atmosphere in order of the one closest to the surface to the furthest one away from the surface.

Answer 8

Troposphere → Stratosphere → Mesosphere → Thermosphere

Question 9

The troposphere goes up until what altitude?

Answer 9

Around 12 km

Question 10

What is the lapse rate in the troposphere?

Answer 10

6.5C /km.

Question 11

Does temperature increase or decrease with height in the troposphere?

Answer 11

The temperature decreases with height.

Question 12

In what layer does weather occur? (sometimes called the “weather layer”)

Answer 12

The troposphere

Question 13

Where do thunderstorm clouds usually reach? (where is their max)

Answer 13

The tropopause level

Question 14

Are there sometimes temperature inversions near the surface?

Answer 14

Yes

Question 15

What is the upper boundary of the troposphere called?

Answer 15

Tropopause.

Question 16

At what altitude does the stratosphere end at?

Answer 16

At around 50km.

Question 17

Which atmospheric layer contains the ozone layer?

Answer 17

The stratosphere.

Question 18

Which atmospheric layer contains the highest concentration of ozone?

Answer 18

The stratosphere.

Question 19

Does temperature increase or decrease with height in the stratosphere?

Answer 19

It increases with height.

Question 20

What is one of the main reasons that the temperature increases with height in the stratosphere?

Answer 20

The ozone layer is the main reason for temperature increase; its absorption of solar UV radiation leads to heating up.

Question 21

What is the upper boundary of the stratosphere?

Answer 21

The stratopause.

Question 22

Even though the actual concentration of O2 is close to 21% by volume in the upper stratosphere, why without proper breathing apparatus would you not be able to survive>

Answer 22

Because the air pressure is so low in the upper stratosphere, 21 percent of a very small amount of air does not provide enough oxygen to breathe.

Question 23

At what altitude does the mesosphere end at?

Answer 23

Around 85km

Question 24

Does temperature increase or decrease with height in the mesosphere?

Answer 24

It decreases with height.

Question 25

In what layer of the atmosphere do we find the lowest average air temperature?

Answer 25

The mesosphere.

Question 26

Does temperature increase or decrease with height in the thermosphere?

Answer 26

It increases with height.

Question 27

Why does the temperature increase with height in the thermosphere?

Answer 27

Due to absorption of energetic solar radiation by oxygen molecules.

Question 28

Why does it not feel warm in the thermosphere, even if temperature increases with height in that layer?

Answer 28

Because there are very few molecules per unit volume at this altitude (density decreases with altitude) ; so it would not be warm in terms of human perception.

Question 29

In what layer of the atmosphere do we find the highest average air temperature?

Answer 29

The thermosphere.

Question 30

What are the layers of the atmosphere by composition and electric charge?

Answer 30

Homosphere → Heterosphere → Ionosphere

Question 31

What is the homosphere?

Answer 31

The homosphere is the well-mixed “lower” atmosphere (until ≈80km). It’s composition is 78% N2 and 21% O2.

Question 32

What is the heterosphere?

Answer 32

The heterosphere is the poorly mixed “upper” atmosphere (Above ≈80km).
It contains different molecular masses of air constituents that are important for mixing/ un-mixing

Question 33

What is the ionosphere?

Answer 33

• An electrified region with ions and free electrons.
• The ionosphere contains a large fraction of electrically charged atoms (ions) among air constituents.
• It is above ≈60 km altitude.

Question 34

Which sphere plays a major role in radio communications?

Answer 34

The ionosphere.

Question 35

How does the ionosphere play a role in radio communications?

Answer 35

At night, the higher region of the ionosphere, the F region, strongly reflects AM radio waves, allowing them to be sent over great distances. During the day, the lower D region strongly absorbs and weakens AM radio waves, preventing them from being picked up by distant receivers.

Question 36

What causes the Earth to behave like a giant magnet?

Answer 36

The Earth’s molten metal core.

Question 37

What is solar wind?

Answer 37

• Solar wind is the high-energy ionized particles that are continually discharged by the Sun. Also called plasma.
• Solar wind is extremely dangerous to life on Earth.

Question 38

What protects us from solar wind?

Answer 38

The Earth’s magnetic field.

Question 39

How is the aurora produced?

Answer 39

The sun releases a continuous discharge of particles. As these charged particles travel through space, they are known as solar wind. When the solar wind moves close enough to Earth, it interacts with Earth’s magnetosphere. High-energy particles within the magnetosphere are ejected into Earth’s upper atmosphere, where they excite atoms and molecules. The excited atmospheric gases emit visible radiation, which causes the sky to glow.

Question 40

What are auroras called in the different hemispheres? (NH and SH)

Answer 40

NH: Aurora Borealis / Northern lights
SH: Aurora Australis