2^nd Hour Exam (2) Mteor 206 Spring 1999

1. Radiation fog formation is similar to

1. the dew point process
2. the saturation vapor pressure process
3. convective processes

1. Advection fog formation is similar to

1. the dew point process
2. the saturation vapor pressure process
3. convective processes

1. During a 24 hour period, when the air temperature rises and falls,

1. atmospheric pressure rises and falls
2. atmospheric pressure falls and rises
3. relative humidity rises and falls
4. relative humidity falls and rises
5. none or the above

If one measured the temperature of an air parcel as it passed over a mountain one would notice (for 4, 5):

1. On ascent the temperature _____ until a cloud formed and then it _____.

1. decreased, decreased faster
2. decreased, decreased slower
3. increased, increased faster
4. decreased, increased

1. That as the air passed down the mountain

1. the air warms
2. the cloud increases
3. the air cools

1. When air moves over a mountain such that rain falls, the temperature below the cloud on the front (windward) side is _____ compared with the same elevation on the back (lee) side

1. warmer
2. cooler
3. not changed
4. cooler or warmer depending on cloud cover

1. Of the three humidity measures, relative humidity, specific humidity and mixing ratio _____ and _____ are most similar.

1. relative humidity, specific humidity
2. relative humidity, mixing ratio
3. specific humidity, mixing ratio

1. Frost is frozen dew

a) T, b) F

2. Dew forms when air is cooled sufficiently because

1. air changes isobarically to the saturation vapor pressure
2. cooling reduces the saturation vapor pressure to the actual vapor pressure
3. vapor is released as cooling occurs
4. (a) and (b)

1. If you took temperature measurements from a balloon on a clear day and found the temperature decreased by 10^oC for every 1000 m change in elevation this would be an example of

1. a normal atmosphere
2. an abnormal atmosphere
3. an unstable atmosphere
4. a stable atmosphere
5. a neutral atmosphere

1. When the humidity is high the dew point depression is _____ and the wet bulb depression is _____.

1. low, high
2. low, low
3. high, low
4. high, high

1. An instrument used to determine humidity is

1. psychrometer
2. aspirometer
3. lidar
4. all of the above

1. When the saturation vapor pressure equals the atmospheric pressure

1. the dew point temperature equals the wet bulb temperature
2. the dry bulb temperature equals the wet bulb temperature
3. the dew point depression is zero
4. boiling occurs

1. Frost is

1. frozen dew
2. a consequence of deposition
3. a consequence of condensation

1. Relative humidity depends

1. on both temperature and water vapor amount
2. on water vapor amount only
3. on water vapor amount relative to the dew point temperature
4. on water vapor amount relative to dew point depression

1. Saturation vapor pressure depends on

1. actual vapor pressure
2. air temperature
3. dew point depression
4. (a) and (b)

1. Fog can form by

1. cooling the air to the dew point temperature
2. adding water vapor to the air
3. both (a) and (b)

1. "Steam" on Lake LaVerne is seen in the _____ and is a fog caused by _____.

1. spring, advection of warm air over cold water
2. spring, advection of cold air over warm water
3. fall, evaporation into cold air
4. fall, evaporation into warm air

1. If air temperature doesn't change, saturation

1. can't occur
2. can occur if water vapor is added

1. Which association is not correct:

1. cirrocumulus - high cloud
2. cumulus - cloud of vertical development
3. altostratus - high cloud
4. stratus - low cloud
5. cumulonimbus - cloud of vertical development

1. When viewed from the surface, the smallest individual cloud elements (puffs) are observed with which cloud?

1. stratocumulus
2. cumulus
3. cirrocumulus
4. altocumulus
5. cumulonimbus

1. Which cloud is composed of ice crystals and can cause a halo to form around the sun or moon?

1. altostratus
2. stratus
3. nimbostratus
4. cirrostratus
5. angelitus

1. A low, lumpy cloud layer that appears in rows, patches or rounded masses is:

1. nimbostratus
2. stratus
3. cumulus
4. altocumulus
5. stratocumulus

1. A difference between sleet and snow is that

1. sleet melted and refroze but snow never melted
2. sleet is liquid until it hits the earth but snow is ice all the time

1. If the temperature remains constant, evaporating water into the air will _____ the dew point and _____ the relative humidity.

1. increase, increase
2. increase, decrease
3. decrease, increase
4. decrease, decrease

1. Light or moderate but steady precipitation is most often associated with _____ clouds.

1. nimbostratus
2. altocumulus
3. cirrostratus
4. cirrocumulus
5. cumulonimbus

1. Which cloud is least likely to produce precipitation that reaches the ground?

1. stratus
2. nimbostratus
3. cumulus congestus
4. cumulonimbus
5. cirrocumulus

1. water droplets
2. carbon dioxide
3. meteoric dust
4. ice particles
5. white powder

29. An air parcel which warms dry adiabatically increases its heat content

1. by conduction
2. by absorption of radiation
3. both (a) and (b)
4. neither (a) nor (b)

29. The slope of the line which represents the change of temperature with height for air which passed over the mountain in the Mtn Sim-Ad when no clouds occurred was

1. the same going up as coming down
2. was greater going up then coming down
3. was greater coming down than going up
4. actually changes the way up but is constant going down

29. On clear nights in winter the atmosphere can actually increase in temperature with distance above the surface. This is an example of

1. a normal atmosphere
2. an abnormal atmosphere
3. an unstable atmosphere
4. a stable atmosphere
5. a neutral atmosphere

29. Which station model corresponds to the lowest humidity:

1. A
2. B
3. C
4. Not possible to tell without knowing the vapor pressure

29. The air parcels in the Mtn Sim change temperature when they change elevation. Which of these are correct:

1. slopes of ascending parcels are always the same
2. slopes of descending parcels are always the same
3. slopes of ascending and descending parcels are always different
4. slopes of ascending and descending parcels are always the same

29. The Mtn Sim activity showed a temperature difference between the same elevation on either side of the mountain

1. as a result of shadow effects of the cloud
2. as a result of solar radiation differences on the different mountain sides
3. when rain occurred because of latent heat gained from condensation
4. all of the above

On a recent sunny day with snow on the ground, at 3 pm the temperature was 30F and the vapor pressure was 4 mb (the saturation vapor pressure at 30^oF is 5.6 mb) when you get up the next day there is widespread fog until about midmorning (for questions 35, 36, 37)

29. The fog formed because

1. warm air raised the vapor pressure
2. cool air lowered the vapor pressure
3. the saturation vapor pressure increased
4. there was a decrease in temperature together with an increase in vapor pressure

29. The dewpoint temperature change between early morning and midmorning the next day

1. increases
2. decreases
3. stays the same

29. The saturation vapor pressure between 3 pm the first day and midnight

1. decreases
2. increases
3. doesn't change

29. Cloud drop growth by _____ is slow but is much faster by _____.

1. diffusion, coalescence
2. diffusion, condensation

29. The reason there are no clouds on the side of the mountain where air descends is

1. adiabatic cooling causes air to go down, thus no clouds
2. all of the water has been removed on the ascending side of the mountain
3. adiabatic warming moves the parcel to the right of the saturation vapor pressure curve
4. actually there can be clouds on either side of the mountain

29. When cold air moves from land over warm water the temperature change is often greater than 10^o/1000 m. This is an example of

1. a normal atmosphere
2. an abnormal atmosphere
3. an unstable atmosphere
4. a stable atmosphere
5. a neutral atmosphere

29. Fog is

1. an altostratus cloud
2. a stratus cloud
3. not really a cloud but huge particles

29. Breweries advertise that pure water from mountains or springs make their beer better. Which statement below is true?

1. neither water from mountains nor springs is pure but rainwater is
2. neither water from mountains nor springs is pure but cloud drops are
3. now, because of man's activities, rainwater is seldom pure but cloud drops still are
4. cloud drops were never pure water

29. Airplane icing is hazardous because

1. a fast flying airplane can cause ice crystals to melt on impact and rime the airplane
2. water drops are common at temperatures as low as -10^oC and the airplane acts as an ice nucleus.
3. ice crystals are mushy as low as -10^oC and "harden" on impact by the airplanes
4. clouds have more ice content in the winter so winter flights are susceptible to icing

29. Mixtures of water drops and ice crystals at -10^oC

1. can't happen since water freezes at 0^oC
2. convert to ice nearly immediately because water freezes at 0^oC
3. convert to ice by a process of diffusion from drops to crystals
4. convert to water as latent heat release warms the entire mixture

29. Refer to the figure:

1. both "A" and "B" have the same dew point

temperature

2. both "A" and "B" have the same relative humidity
3. both (a) and (b) are correct
4. neither (a) nor (b) are correct