Lecture 8 (Humidity, Condensation, and Clouds)

Question 1

The average American family uses more than how many gallons of water per day at home?

Answer 1

300 gallons

Question 2

What percentage of earths surface is covered in water?

Answer 2

70%

Question 3

Why is the specific heat capacity of water important?

Answer 3

It stabilizes our temperature

Question 4

Solid

Answer 4

Molecules move very slowly and are close together

Question 5

Liquid

Answer 5

Molecules move faster and are more spread apart

Question 6

Gas

Answer 6

Molecules move very fast and are very spread apart

Question 7

Evaporation

Answer 7

Changing from liquid(slowly moving) into vapor (fast moving)

Question 8

Condensation

Answer 8

Changing from vapor (fast moving) into liquid (slow moving)

Question 9

We will 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 9

The water in the cup would slowly evaporate away

Question 10

Why is the condensation rate so slow from the cup question?

Answer 10

Because the rate of condensation depends on how much water vapors is in the air.

Question 11

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

Answer 11

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 the amount of water vapor in the air

Question 12

Indices of water vapor content

Answer 12

• water vapor mass
• vapor pressure
  -relative humidity
  -dew point temperature

Question 13

Water vapor mass

Answer 13

• absolute humidity
• specific humidity
• mixing ratio

Question 14

Absolute humidity

Answer 14

Mass of water vapor / volume of air

Question 15

Specific humidity

Answer 15

Mass of the water vapor / mass of air (including water vapor)

Question 16

Mixing ratio

Answer 16

Mass of the water vapor / mass of air without water vapor

Question 17

Saturation vapor pressure

Answer 17

Describe how much water vapor is necessary to make the air saturated at any given temperature

Question 18

The saturation vapor pressure of water increases with?

Answer 18

Temperature (warmer air can hold more water vapor)

Question 19

The relative humidity (RH)

Answer 19

(Actual vapor pressure / saturation vapor pressure) * 100

Question 20

Dew point temperature description

Answer 20

Is the temperature to which air would have to be cooled for saturation to occur

Question 21

The higher the dew point

Answer 21

The more water vapor in the air

Question 22

Relative humidity description

Answer 22

Is the ratio of the amount of water vapor actually in the air to the maximum amount of water vapor required for saturation at that particular temperature and pressure

Question 23

Specific humidity description

Answer 23

The ratio of mass water vapor in a given air parcel to the total mass of air in the parcel

Question 24

Mixing ratio description

Answer 24

The ratio of mass of water vapor in a given air parcel to the total mass of dry air in the parcel

Question 25

Relative humidity description

Answer 25

The ratio of the amount of water vapor in the air compared to the amount of required for saturation

Question 26

Vapor pressure description

Answer 26

The pressure exerted by water vapor molecules in a given volume of air

Question 27

How to measure dew point temperature?

Answer 27

- dew point hygrometer - reflecting a light beam off a chilled mirror - ASOS (automated surface observing system)

Question 28

Two categories of indices

Answer 28

1- a measure of moisture content ( absolute humidity, specified humidity, mixing ratio, vapor pressure, dew point temperature) 2- a measure of how near the air is to being saturated (relative humidity)

Question 29

A common misconception

Answer 29

Air with higher relative humidity must have

Question 30

A common misconception

Answer 30

Air with higher relative humidity must have a greater water vapor content than air with lower relative humidity.

Question 31

Forms of condensation

Answer 31

- dew - frost - fog - cloud

Question 32

3 major types of fog

Answer 32

- radiation fog - advection fog -upslope fog

Question 33

Radiation fog

Answer 33

Fog produced by the earths radiation cooling is called radiation fog or ground fog

Question 34

Advection fog

Answer 34

Warm moist air that moves above a cold surface may become cooled to its dew point temperature, creating an advection fog.

Question 35

Upslope fog

Answer 35

Is formed as moist air flows up along an elevated plain, hill, or mountain

Question 36

Nimbostratus

Answer 36

Is a rain cloud that shows layering

Question 37

Cumulonimbus

Answer 37

Is a rain cloud having pronounced vertical development

Question 38

Cloud type classification by both

Answer 38

Elevations and appearance

Question 39

Four types of cloud appearance

Answer 39

- status: layer or sheet like clouds - cumulus: heal or puffy cloud - cirrus: curl of hair or wispy cloud - nimbus: violent rain or rain clouds