Texas A & M University-College Station ATMO 201 - EXAM 2 ||
Answered Perfectly 100%.
-Expands and cools
-Compresses and warms correct answers What do rising and sinking air do in adiabatic
processes?
Adiabatic process correct answers -No heat gained/lost
-Unsaturated conditions
-Reversible process bc the air parcel has same temp at beginning and end
Stable correct answers -If an object, when forced to move, tends to move back to its original
position
Unstable correct answers -If an object, when forced to move, tends to continue to move away
from its original position
-Warm air (cool air more dense) correct answers At the same height, is warm or cool air less
dense?
Dry-adiabatic lapse rate correct answers -An unsaturated (dry) parcel will always rise and sink at
9.8C per kilometer
-For simplicity sake for this class, we'll use 10C
Moist-adiabatic lapse rate correct answers -When parcels rise and cool, they'll eventually become
saturated
-As they continue to rise, water vapor will condense into liquid water (a cloud)
Remember: during condensation, latent heat released inside parcel
-Instead of cooling at 10C per km, it cools slower appx 6C per km
,Environmental lapse rate correct answers -Parcels always rise/sink at either dry or moist
adiabatic lapse rate
-The air surrounding parcel can have a variety of temps
-Measured w radiosondes
-Since adiabatic lapse rates are known, we can compare them to environmental lapse rate to
determine whether parcel will be stable/unstable
-If a parcel is forced to rise, and it's warmer than its environment, it will continue to rise and be
unstable
-If it is forced to rise and is cooler than its environment, it will sink back down to the original
position and be stable
Absolutely stable correct answers -When environmental lapse rate is less than adiabatic rate (6C
per km)
-Air parcels will be colder than their environment and sink back to their original position
-Temp inversion (temp increase w height) acts as a lid
-Often occurs at night due to radiational cooling
Absolutely unstable correct answers -When environmental lapse rate is greater than dry-adiabatic
lapse rate (10C per km)
-Air parcels will be warmer than their environment and continue to rise
-This condition usually only occurs near the surface, and not for very long since the rising
parcels will bring the warm air up and cool air will mix down around them
Conditionally unstable correct answers -When environmental lapse rate is between the dry and
moist adiabatic lapse rates (6C and 10C per km)
-Unsaturated parcels will sink back to their original position, saturated parcels will continue to
rise
-There is instability, on the condition that the parcel is saturated
-On avg, the atmosphere in this state (avg environmental lapse rate is 6.5C per km)
, -This helps to explain why cumulus clouds can grow v tall into cumulonimbus bc ONLY
saturated parcels continue to rise
-Free convection level (LFC)
Naturally stable correct answers -When environmental lapse rate equals the dry adiabatic lapse
rate
-Unsaturated parcels will not tend to rise or sink in this condition, instead they stay where they
are
-If environmental lapse rate equals the moist adiabatic lapse rate, then the atmosphere is ___ for
saturated parcels
-Warming at low levels or cooling aloft
-Mixing
-Lifting or subsidence in layers correct answers What factors can cause changes in stability?
Warming at low levels or cooling aloft correct answers -Increases lapse rate
-Makes atmosphere less stable
-"Warm air advection" at low levels will destabilize the atmospehre
Mixing correct answers -Makes atmosphere more stable if absolutely unstable
-Makes atmosphere unstable if stable
Lifting or subsidence in layers correct answers -If a whole layer sinks, it compresses in the
denser air near the ground, top warms more than bottom and becomes more stable
-If a whole layer rises, it stretches in the less dense air aloft, it tends to become more unstable,
esp when the bottom is saturated and the top is dry
Convective instability correct answers -If a whole layer rises, it stretches in the less dense air
aloft, it tends to become more unstable, esp when the bottom is saturated and the top is dry
Answered Perfectly 100%.
-Expands and cools
-Compresses and warms correct answers What do rising and sinking air do in adiabatic
processes?
Adiabatic process correct answers -No heat gained/lost
-Unsaturated conditions
-Reversible process bc the air parcel has same temp at beginning and end
Stable correct answers -If an object, when forced to move, tends to move back to its original
position
Unstable correct answers -If an object, when forced to move, tends to continue to move away
from its original position
-Warm air (cool air more dense) correct answers At the same height, is warm or cool air less
dense?
Dry-adiabatic lapse rate correct answers -An unsaturated (dry) parcel will always rise and sink at
9.8C per kilometer
-For simplicity sake for this class, we'll use 10C
Moist-adiabatic lapse rate correct answers -When parcels rise and cool, they'll eventually become
saturated
-As they continue to rise, water vapor will condense into liquid water (a cloud)
Remember: during condensation, latent heat released inside parcel
-Instead of cooling at 10C per km, it cools slower appx 6C per km
,Environmental lapse rate correct answers -Parcels always rise/sink at either dry or moist
adiabatic lapse rate
-The air surrounding parcel can have a variety of temps
-Measured w radiosondes
-Since adiabatic lapse rates are known, we can compare them to environmental lapse rate to
determine whether parcel will be stable/unstable
-If a parcel is forced to rise, and it's warmer than its environment, it will continue to rise and be
unstable
-If it is forced to rise and is cooler than its environment, it will sink back down to the original
position and be stable
Absolutely stable correct answers -When environmental lapse rate is less than adiabatic rate (6C
per km)
-Air parcels will be colder than their environment and sink back to their original position
-Temp inversion (temp increase w height) acts as a lid
-Often occurs at night due to radiational cooling
Absolutely unstable correct answers -When environmental lapse rate is greater than dry-adiabatic
lapse rate (10C per km)
-Air parcels will be warmer than their environment and continue to rise
-This condition usually only occurs near the surface, and not for very long since the rising
parcels will bring the warm air up and cool air will mix down around them
Conditionally unstable correct answers -When environmental lapse rate is between the dry and
moist adiabatic lapse rates (6C and 10C per km)
-Unsaturated parcels will sink back to their original position, saturated parcels will continue to
rise
-There is instability, on the condition that the parcel is saturated
-On avg, the atmosphere in this state (avg environmental lapse rate is 6.5C per km)
, -This helps to explain why cumulus clouds can grow v tall into cumulonimbus bc ONLY
saturated parcels continue to rise
-Free convection level (LFC)
Naturally stable correct answers -When environmental lapse rate equals the dry adiabatic lapse
rate
-Unsaturated parcels will not tend to rise or sink in this condition, instead they stay where they
are
-If environmental lapse rate equals the moist adiabatic lapse rate, then the atmosphere is ___ for
saturated parcels
-Warming at low levels or cooling aloft
-Mixing
-Lifting or subsidence in layers correct answers What factors can cause changes in stability?
Warming at low levels or cooling aloft correct answers -Increases lapse rate
-Makes atmosphere less stable
-"Warm air advection" at low levels will destabilize the atmospehre
Mixing correct answers -Makes atmosphere more stable if absolutely unstable
-Makes atmosphere unstable if stable
Lifting or subsidence in layers correct answers -If a whole layer sinks, it compresses in the
denser air near the ground, top warms more than bottom and becomes more stable
-If a whole layer rises, it stretches in the less dense air aloft, it tends to become more unstable,
esp when the bottom is saturated and the top is dry
Convective instability correct answers -If a whole layer rises, it stretches in the less dense air
aloft, it tends to become more unstable, esp when the bottom is saturated and the top is dry
