Chapter 3

Question 1

The atmosphere can be divided by…

Answer 1

1. Composition
2. Function
3. Temperature

Question 2

List the categories for COMPOSITION:

Answer 2

HOMOSPHERE (bottom/ under 80k)
- Same composition of gases (nitrogen, oxygen, etc)

HETEROSPHERE (top part/ above 80k)
- Different elevations men different gasses. Heaviest at the bottom, lightest at top.

Question 3

List the categories for FUNCTION:

Answer 3

OZONOSPHERE

IONOSPHERE

Question 4

List the categories for TEMPERATURE:

Answer 4

THERMOSPHERE

STRATOSPHERE

MESOSPHERE

TROPOSPHERE

Question 5

Photochemical Smog

Answer 5

Result of the interaction of sunlight and the combustion products in automobile exhaust

Question 6

PARTICULATE MATTER

Answer 6

diverse mixture of fine particles, both solid and liquid, that pollute the air and affect human health.

examples: haze, smoke, dust, sulfate aerosol

Question 7

Black carbon / Soot

Answer 7

an aerosol having devastation health effects in developing countries

• absorbs heat in the atmosphere and changes the reflectivity of surfaces such as snow and ice

Question 8

Haze

Answer 8

concentration of microscopic particles and air pollution that diminishes clarity

Question 9

Air

Answer 9

simple mixture of gases that is naturally odorless, colorless, tasteless, formless, blended so thoroughly that it behaves as if it were a single gas.

Question 10

Extent of the Atmosphere

Answer 10

480km

Question 11

Carbon Dioxide

Answer 11

Natural by-product of life, a variable gas that is increasing rapidly

• absorbs radiation, warming the earth
• too little causes global cooling

Question 12

Air pressure

Answer 12

Air molecules create air pressure (through their motion, size and number,) exerting forces on all surfaces they come in contact with

• measured in force per unit area

Question 13

Why are CFC’s bad for the ozone layer?

Answer 13

Chlorofluorocarbons react with UV light to release chlorine which then destroys ozone molecules.

Question 14

Insolation

Answer 14

• Exposure to the sun’s rays

- Intercepted solar radiation

Question 15

HETEROSPHERE

Answer 15

80km-480km altitude

Gases are not evenly mixed. They occur in distinct layers sorted by gravity according to their atomic weight.

Question 16

HOMOSPHERE

Answer 16

Earth’s Surface - 80km altitude

With exception of the ozone layer and variations in pollution, and water vapour in the lower atmosphere, it is composed of a near uniform mixture of gases.

Question 17

Gases in the Homosphere (5)

Answer 17

Nitrogen

Oxygen

Argon

Carbon Dioxide

Trace Gases

Question 18

THERMOSPHERE

Answer 18

80-480 km in altitude

Temperatures increase with altitude

1200 °C + temperatures, but not “hot”

Height depends on solar activity (less solar activity = lower)

Question 19

MESOSPHERE

Answer 19

50-80 km altitude

Temperatures decrease with altitude.

Cosmic + meteoric dust provide nuclei for ice crystals to form. (notillucent clouds)

Extremely low pressures

Question 20

STRATOSPHERE

Answer 20

18 - 50 km altitude

Contains the OZONE LAYER

Temperatures increase with altitude

Question 21

TROPOSPHERE

Answer 21

Sea Level - 18 km altitude

• Thickness controlled by surface temperatures (18 km at equator, 8km at poles)
• temperatures decrease with altitude (normal lapse rate which is 6.4 °C)
• Mixing of air of troposphere and stratosphere is prevented because troposphere is cooler, denser than stratosphere which is warmer, less dense

Question 22

Tropopause

Answer 22

Occurs wherever -57°c in the troposphere is measured.

Question 23

Mesopause

Answer 23

averaging at –90°C, the coldest part of the atmosphere.

Question 24

Stratopause temperature

Answer 24

0°C

Question 25

Thermopause

Answer 25

Approximately 480 km in altitude that serves conceptually as the top of the atmosphere

Question 26

"-pause"

Answer 26

Where one layer of the atmosphere ends and another begins. Generally defined by temperature change.

Question 27

Normal Lapse Rate

Answer 27

The average rate of temperature decrease with increasing altitude in the lower atmosphere aprox 6.5 C°/km

Question 28

Environmental Lapse Rate

Answer 28

The actual rate of temperature decrease with increasing altitude in the lower atmosphere at any particular time and place. varies between 5-12C°/km

Question 29

Temperature Inversion

Answer 29

Occurs when the normal temperature, which usually decreases with altitude (normal lapse rate), reverses trend and begins to increase at some point.

Question 30

Cause of Temperature Inversion

Answer 30

Cold dense air has warmer less dense air overlying it. This stops mixing and the air in the lower portion becomes trapped (in an inversion layer). Pollutants are trapped beneath the inversion.

Question 31

Ozonosphere

Answer 31

Ozone layer Responsible for the absorption of harmful UV rays - three oxygen molecules - UVB and UVA are absorbed and reradiated as infared rays

Question 32

Ozone

Answer 32

Ozone is a highly reactive oxygen molecule made up of three oxygen atoms (O3) instead of the usual two atoms (O2) that make up oxygen gas.

Question 33

Function of Ozone

Answer 33

Ozone absorbs... 100% of UVC 90% UVB 50% of UVA

Question 34

3 types of UV

Answer 34

UVA UVB UVC

Question 35

Dobson Unit (DU)

Answer 35

Measure of the concentration of ozone in the atmosphere,

Question 36

Global average dobson Unit

Answer 36

300,000DU

Question 37

Dobson Unit Value where we consider it a 'hole in the ozone'

Answer 37

Under 220,000 DU

Question 38

What harms the ozone layer?

Answer 38

Compounds containing Chlorine and Bromine (eg. Chlorofluorocarbons)

Question 39

Science of Ozone Depletion chemistry

Answer 39

Cl + O3----uv----> ClO+ O2 and ClO+ O3----uv----> Cl+ 2O2

Question 40

The process of ozone depletion through the chemical reaction with Chlorine is an example of...

Answer 40

a positive feedback loop

Question 41

The ozone depletion reaction is assisted by the

Answer 41

Sun

Question 42

Ozone depletion explained

Answer 42

Occurs when CFC's and sunlight react, breaking down Ozone, causing a hole in the ozone layer.

Question 43

Special conditions of Ozone depletion reaction

Answer 43

Extremely Low temperatures (Conditions for Polar Stratospheric Clouds) UV (sunlight) Solid Surface

Question 44

Polar Stratospheric Clouds

Answer 44

Clouds made up of small particles of ice (ice crystals). They provide the solid surface required for the two ozone depleting chemical reactions to occur.

Question 45

Antarctic Vortex

Answer 45

High velocity of wind that circulates around Antarctica. | It contains the highest concentration of CFCS (they get sucks in). Locus of the worst destruction of the ozone.

Question 46

Worst ozone damage occurs when?

Answer 46

September, when there is the perfect conditions for a combination of lots of sun and low temperatures.

Question 47

"Bad Ozone"

Answer 47

Ground level ozone is a highly unstable gas. | It damages plants, and irritates human eyes, nose and throats

Question 48

Exosphere

Answer 48

An extremely rarefied outer atmospheric halo beyond the thermopause at an altitude of 480 km