GEG 111 EXAM 2 HARPER COLLEGE LATEST ACTUAL EXAM
Properties of water - ANSWER: • Exists as a liquid at most places on Earth's surface
• Expands when it freezes; which is important in the weathering of rock
• Hydrogen bonding creates surface tension, a "skin" of molecules giving water a
stickiness
quality - surface tension
• Capillarity; water can "climb" up narrow openings. This is important to the
movement of
groundwater.
• Good solvent; water dissolves most substances
• High specific heat; it takes a relatively high amount of energy to raise the
temperature of
water.
Phase Changes and Heat Exchange - ANSWER: Water absorbs or releases energy as it
changes from one state to another.
• IMPORTANT: The heat exchanged between physical states of water provides more
than
30% of the energy that powers the general circulation of the atmosphere.
Latent Heat - ANSWER: The heat energy absorbed or released during a phase
change.
Three phases of water - ANSWER: 1) Ice: solid phase
2)Water: liquid phase
3)Water Vapor: gas phase
Ice, the solid phase - ANSWER: • Upon freezing water expands in volume and density
(Note: maximum density occurs
while water is still in a liquid phase, at 4°C (39°F)
• The decrease in density manifests itself in the buoyancy of ice in water
• The increase in volume can damage infrastructure e.g. roads, pipes and plays an
important role in the weathering (breakdown) of rocks
Water, the liquid phase - ANSWER: Non-compressible fluid that assumes the shape
of its container
• The phase change from ice absorbs heat energy
• A good solvent
Water vapor, the gas phase - ANSWER: • Invisible and compressible gas
• We see water vapor in the atmosphere after condensation has occurred in the
form
of clouds, fog, and steam
• Water vapor is a greenhouse gas
, Humidity - ANSWER: Humidity is the amount of water vapor in the air
• The water holding capacity of air is influenced by temperature of the air and water
vapor
• Humidity and air temperature determine our sense of comfort
Relative humidity - ANSWER: A measure of how close the air is to saturation (%
saturation) at a given temperature or the ratio of the amount of water vapor is in the
air compared to the maximum amount of water vapor that the air can hold at a given
temperature
• Because there is a maximum amount of water vapor that can exist in a volume of
air at a
given temperature, the rates of evaporation and condensation can reach equilibrium
at
some point.
Saturation and Dew point - ANSWER: • Saturation = 100% humidity
• Dew-point temperature: temperature at which a given sample of air becomes
saturated with water vapor and net condensation begins.
Dry Adiabatic Rate (DAR) - ANSWER: rate at which "dry" air (i.e. unsaturated air)
cools by expansion as it rises or warms by compression as it falls. The average DAR is
10 C°/1000 m (5.5
F°/1000 ft.)
Moist Adiabatic Rate (MAR) - ANSWER: rate at which saturated air cools by
expansion as it rises or warms by compression as it falls. The average DAR is 6
C°/1000 m (3.3 F°/1000 ft.)
• MAR is lower than DAR because of the latent heat of condensation (cooling) and
the
latent heat of evaporation (heating)
Environmental Lapse Rate (ELR) - ANSWER: The decrease in temperature with
increasing altitude at a particular location and time.
Stable Atmospheric conditions - ANSWER: The stability of air can be determined by
comparing the DAR, MAR, and ELR rates at a
location.
• Stable Air: The DAR and MAR are greater than the ELR with altitude. i.e. the air
parcel is cooler than the surrounding air with increasing altitude. The tendency will
be to resist upward movement.
Unstable Atmospheric conditions - ANSWER: Unstable Air: The DAR and MAR are
lower than the ELR with altitude. i.e. the air parcel is warmer than the surrounding
air with increasing altitude. The tendency will be to rise until temperature and
density are equal.
• Conditionally Unstable Air: the ELR is between the DAR and MAR. If the air parcel is
less
Properties of water - ANSWER: • Exists as a liquid at most places on Earth's surface
• Expands when it freezes; which is important in the weathering of rock
• Hydrogen bonding creates surface tension, a "skin" of molecules giving water a
stickiness
quality - surface tension
• Capillarity; water can "climb" up narrow openings. This is important to the
movement of
groundwater.
• Good solvent; water dissolves most substances
• High specific heat; it takes a relatively high amount of energy to raise the
temperature of
water.
Phase Changes and Heat Exchange - ANSWER: Water absorbs or releases energy as it
changes from one state to another.
• IMPORTANT: The heat exchanged between physical states of water provides more
than
30% of the energy that powers the general circulation of the atmosphere.
Latent Heat - ANSWER: The heat energy absorbed or released during a phase
change.
Three phases of water - ANSWER: 1) Ice: solid phase
2)Water: liquid phase
3)Water Vapor: gas phase
Ice, the solid phase - ANSWER: • Upon freezing water expands in volume and density
(Note: maximum density occurs
while water is still in a liquid phase, at 4°C (39°F)
• The decrease in density manifests itself in the buoyancy of ice in water
• The increase in volume can damage infrastructure e.g. roads, pipes and plays an
important role in the weathering (breakdown) of rocks
Water, the liquid phase - ANSWER: Non-compressible fluid that assumes the shape
of its container
• The phase change from ice absorbs heat energy
• A good solvent
Water vapor, the gas phase - ANSWER: • Invisible and compressible gas
• We see water vapor in the atmosphere after condensation has occurred in the
form
of clouds, fog, and steam
• Water vapor is a greenhouse gas
, Humidity - ANSWER: Humidity is the amount of water vapor in the air
• The water holding capacity of air is influenced by temperature of the air and water
vapor
• Humidity and air temperature determine our sense of comfort
Relative humidity - ANSWER: A measure of how close the air is to saturation (%
saturation) at a given temperature or the ratio of the amount of water vapor is in the
air compared to the maximum amount of water vapor that the air can hold at a given
temperature
• Because there is a maximum amount of water vapor that can exist in a volume of
air at a
given temperature, the rates of evaporation and condensation can reach equilibrium
at
some point.
Saturation and Dew point - ANSWER: • Saturation = 100% humidity
• Dew-point temperature: temperature at which a given sample of air becomes
saturated with water vapor and net condensation begins.
Dry Adiabatic Rate (DAR) - ANSWER: rate at which "dry" air (i.e. unsaturated air)
cools by expansion as it rises or warms by compression as it falls. The average DAR is
10 C°/1000 m (5.5
F°/1000 ft.)
Moist Adiabatic Rate (MAR) - ANSWER: rate at which saturated air cools by
expansion as it rises or warms by compression as it falls. The average DAR is 6
C°/1000 m (3.3 F°/1000 ft.)
• MAR is lower than DAR because of the latent heat of condensation (cooling) and
the
latent heat of evaporation (heating)
Environmental Lapse Rate (ELR) - ANSWER: The decrease in temperature with
increasing altitude at a particular location and time.
Stable Atmospheric conditions - ANSWER: The stability of air can be determined by
comparing the DAR, MAR, and ELR rates at a
location.
• Stable Air: The DAR and MAR are greater than the ELR with altitude. i.e. the air
parcel is cooler than the surrounding air with increasing altitude. The tendency will
be to resist upward movement.
Unstable Atmospheric conditions - ANSWER: Unstable Air: The DAR and MAR are
lower than the ELR with altitude. i.e. the air parcel is warmer than the surrounding
air with increasing altitude. The tendency will be to rise until temperature and
density are equal.
• Conditionally Unstable Air: the ELR is between the DAR and MAR. If the air parcel is
less
