Exam 2

Question 1

Which of the following takes the most amount of water?

A) Running your dishwasher every day for a month
B) Manufacturing a cotton shirt
C) An 8 oz steak
D) 1 cup of coffee

Answer 1

C) An 8 oz steak

Question 2

How many gallons of water does an average American family use daily at home?

Answer 2

more than 300 gallons

Question 3

True/False: Water is extremely important in the earth system

Answer 3

True

Question 4

What percent of Earth’s surface is covered by water?

Answer 4

70% of the Earth’s surface is covered by water

Question 5

Which property of water helps stabilize Earth’s temperature?

Answer 5

High specific heat capacity

Question 6

Water can exist in all three phases at the same temperature due to:

a) Changes in atmospheric pressure
b) High energy absorption rates
c) The absorption and release of latent heat
d) Its ability to reflect solar radiation

Answer 6

c) the absorption and release of latent heat

Question 7

Which phase change releases latent heat into the atmosphere?

a) Evaporation
b) Sublimation
c) Condensation
d) Melting

Answer 7

c) condensation

Question 8

What is the primary role of water vapor in the climate system?

a) To reflect incoming solar radiation
b) To transport heat energy
c) To cool down the Earth’s core
d) To increase wind speeds

Answer 8

b) To transport heat energy

Question 9

What is the relative humidity when air is fully saturated?

Answer 9

100%

Question 10

What happens when the dew point temperature equals the actual temperature?

Answer 10

Condensation begins

Question 11

What is absolute humidity?

Answer 11

The amount of water vapor per unit volume of air

Question 12

Which factor directly affects relative humidity?

Answer 12

Temperature

Question 13

If air temperature increases but moisture content remains constant, what happens to relative humidity?

a) It increases
b) It decreases
c) It stays the same
d) It reaches saturation

Answer 13

b) It decreases

Question 14

Which type of fog is formed when moist air cools due to longwave radiation loss at night?

a) Radiation fog
b) Advection fog
c) Upslope fog
d) Valley fog

Answer 14

a) Radiation

Question 15

What type of cloud is typically associated with fair weather but can develop into storm clouds?

a) Cirrus
b) Cumulus
c) Stratus
d) Nimbostratus

Answer 15

b) Cumulus

Question 16

Nimbostratus clouds are best characterized as:

a) High-altitude clouds composed of ice crystals
b) Thick clouds that produce continuous, steady precipitation
c) Puffy, white clouds that indicate fair weather
d) Clouds that form only in mountainous regions

Answer 16

b) Thick clouds that produce continuous, steady precipitation

Question 17

Which factor contributes most to fog formation?

a) Decreasing temperature and increasing humidity
b) Increasing temperature and decreasing humidity
c) Strong winds
d) High atmospheric pressure

Answer 17

a) Decreasing temperature and increasing humidity

Question 18

How does advection fog form?

a) By longwave radiational cooling of the ground
b) When warm, moist air moves over a cooler surface
c) From rising moist air over mountains
d) Through condensation in high-altitude clouds

Answer 18

b) When warm, moist air moves over a cooler surface

Question 19

What happens to a rising air parcel in an unstable atmosphere?

a) It returns to its original height
b) It accelerates upward
c) It remains at the same height
d) It expands but does not cool

Answer 19

b) It accelerates upward

Question 20

The dry adiabatic lapse rate (DALR) is:

a) 6°C per km
b) 8°C per km
c) 10°C per km
d) 12°C per km

Answer 20

c) 10°C per km

Question 21

If the environmental lapse rate (ELR) is smaller than both the dry and moist adiabatic lapse rates, the atmosphere is:

a) Absolutely unstable
b) Conditionally unstable
c) Absolutely stable
d) Neutral

Answer 21

c) Absolutely stable

Question 22

What process causes a rising air parcel to cool?

a) Evaporation
b) Adiabatic expansion
c) Condensation
d) Frictional heating

Answer 22

b) Adiabatic expansion

Question 23

If an air parcel is lifted and cools at the moist adiabatic lapse rate, what is occurring inside the parcel?

a) No heat exchange with the surroundings
b) Heat is absorbed from the surrounding air
c) Latent heat is being released due to condensation
d) The air parcel is experiencing rapid cooling due to radiation

Answer 23

c) Latent heat is being released due to condensation

Question 24

In warm clouds, what process primarily leads to raindrop formation?

a) Bergeron process
b) Sublimation
c) Collision-coalescence
d) Accretion

Answer 24

c) Collision-coalescence

Question 25

Which precipitation type forms when supercooled raindrops freeze upon impact with a surface? a) Sleet b) Freezing rain c) Graupel d) Hail

Answer 25

b) Freezing rain

Question 26

What is the key factor that allows the Bergeron process to occur? a) The presence of supercooled water and ice crystals in the same cloud b) High surface temperatures c) High wind speeds d) A lack of condensation nuclei

Answer 26

a) The presence of supercooled water and ice crystals in the same cloud

Question 27

Hail formation occurs when: a) Rain droplets freeze in midair before reaching the ground b) Snowflakes melt and refreeze before hitting the ground c) Ice pellets are repeatedly lifted and coated with layers of supercooled water d) Clouds release ice crystals that do not melt

Answer 27

c) Ice pellets are repeatedly lifted and coated with layers of supercooled water

Question 28

Which instrument is commonly used to measure precipitation? a) Anemometer b) Barometer c) Rain gauge d) Hygrometer

Answer 28

c) Rain gauge

Question 29

We fill a cup with some room temperature water and let it sit on a table for a day or two. What will happen to the water?

Answer 29

The water in the cup would slowly evaporate away.

Question 30

We fill a cup with some room temperature water and let it sit on a table for a day or two. Why is the condensation rate so slow?

Answer 30

Because the rate of condensation depends on how much water vapor is in the air. In this case (an open system), the air of the big environment is very dry.

Question 31

If we heat up the water, what will happen to the evaporation, condensation, and water vapor content in the air?

Answer 31

The rate of evaporation increases with increasing temperature. This requires higher and higher rates of condensation to balance the rate of evaporation. Higher and higher rates of condensation means increasing amounts of water vapor in the air.

Question 32

The relative humidity is 100%. The air temperature is 20 °C. What is the dew point temperature?

Answer 32

= 20°C

Question 33

Which environment has higher water vapor content? Desert air or polar air?

Answer 33

Desert air

Question 34

We have an air parcel with pressure larger than the surrounding environment. What will happen to the air volume and air temperature?

Answer 34

* The air parcel will expand due to the pressure difference * As it expands, it does work to the environment. * Doing work consumes energy. So, the air parcel temperature drops. **Expanding air cools down; Compressing air heats up**

Question 35

If the air hits saturation, condensation occurs (and a cloud forms). If the air continues rising, what will happen to the lapse rate?

Answer 35

Condensation releases heat that is used to heat up the air parcel. This dampens the adiabatic cooling by parcel expansion. The lapse rate will decrease to 6 °C /km: moist adiabatic lapse rate.

Question 36

Why do some clouds cause precipitation while others don’t?

Answer 36

Because cloud droplets must grow big enough to fall as precipitation

Question 37

How do we measure precipitation?

Answer 37

1. Rain Gauge 2. Weather radar 3. Satellite

Question 38

If the actual vapor pressure is 10 mb and the saturation vapor pressure is 40 mb, what is the relative humidity?

Answer 38

25%

Question 39

If an air parcel rises 2 km and follows the dry adiabatic lapse rate, by how much will its temperature decrease?

Answer 39

20°C decrease

Question 40

If an air parcel is lifted and cools at a rate of 6°C/km, what type of lapse rate is it following?

Answer 40

* The dry adiabatic lapse rate is 10°C/km. * The moist adiabatic lapse rate is 6°C/km. * Since the given cooling rate is 6°C/km, it corresponds to the moist adiabatic lapse rate. Answer: Moist Adiabatic Lapse Rate

Question 41

The dew point temperature is 50°F, and the air temperature is 86°F. What is the relative humidity if the saturation vapor pressure at 86°F is 42 mb and the actual vapor pressure is 12 mb?

Answer 41

29%

Question 42

Explain why ice crystals grow at the expense of water droplets in the Bergeron process.

Answer 42

* Ice crystals and water droplets coexist in a cloud. * The saturation vapor pressure over ice is lower than over water. * Water vapor molecules move from the droplets (higher pressure) to the ice crystals (lower pressure). * This causes the ice crystals to grow while the water droplets shrink. Answer: Ice crystals grow at the expense of water droplets due to the difference in saturation vapor pressure.

Question 43

What are the four basic types of clouds based on their appearance?

Answer 43

- Stratus (layered) - Cumulus (puffy) - Cirrus (wispy) - Nimbus (rain-bearing)

Question 44

Explain why condensation occurs when air cools.

Answer 44

As air cools, its capacity to hold water vapor decreases. When it reaches the dew point, excess water vapor condenses into liquid droplets.

Question 45

What is the difference between absolute humidity and relative humidity?

Answer 45

* Absolute humidity measures the actual amount of water vapor in the air. * Relative humidity is the ratio of actual water vapor to the maximum possible at a given temperature.

Question 46

(True/False) Water can exist in all three phases (solid, liquid, and gas) at the same temperature.

Answer 46

True

Question 47

(True/False) Relative humidity is always highest in the desert.

Answer 47

False

Question 48

(True/False) The dew point temperature is always higher than the air temperature.

Answer 48

False

Question 49

(True/False) Clouds form due to condensation of water vapor.

Answer 49

True

Question 50

(True/False) The moist adiabatic lapse rate is always greater than the dry adiabatic lapse rate.

Answer 50

False

Question 51

What happens to an air parcel as it rises in the atmosphere? a) It compresses and warms b) It expands and cools c) It remains unchanged d) It condenses and becomes heavier

Answer 51

b) It expands and cools

Question 52

Which cloud type is known for its puffy, heap-like appearance? a) Stratus b) Nimbus c) Cumulus d) Cirrus

Answer 52

c) Cumulus

Question 53

Which type of fog is produced by the Earth’s radiational cooling? a) Advection fog b) Radiation fog c) Upslope fog d) Frontal fog

Answer 53

b) Radiation fog

Question 54

What is the temperature at which air must be cooled to reach saturation? a) Freezing point b) Boiling point c) Dew point d) Absolute humidity

Answer 54

c) Dew point

Question 55

What does relative humidity measure? a) The absolute amount of water vapor in the air b) The ratio of actual vapor pressure to the saturation vapor pressure c) The air temperature d) The pressure of dry air

Answer 55

b) The ratio of actual vapor pressure to the saturation vapor pressure