Lecture 13: Lapse Rates and Stability Flashcards
Adiabatic process
no lose or gain of temperature
no energy exchange with surroundings
What happens to rising and sinking air parcels
an air parcel cools or warms adiabatically as it rises or sinks
Lifitng: causes adiabatic cooling
Sinking: causes adiabatic warming
Ideal gas law
relates pressure (P) temperature (T) and density (p)
Dew point temperatures
Temperature and process of 1500M
T = 19 C, lifted parcel is saturated, continues to cool
Dew point temperatures
Temperature and process of 1000M
T = 22 C, dew point = 22 C
LCL, some water vapor condenses
Dew point temperatures
Temperature and process of 500M
T = 27 C, dew point = 22 C
lifted parcel is expanding and cooling
Dew point temperature
Temperature of surface
T = 32 C, dew point = 22 C
LCL
height where lifted parcel is cooled to its dew point
How adiabatic processes move energy aloft in the atmosphere to power weather systems
Rising parcel is subject to less pressure → volume increases (expansion) → less molecular collisions = cooling
Characteristics of stable atmospheres
parcel is cooling faster than aurrounding environment
parcel is cooler and denser than surrounding air so it sinks
Characteristics of unstable atmosphere
surrounding environment is cooling faster than parcel
parcel is warmer and less dense than surrounding air so it rises
Instability
increases by warming the surface
or cooling aloft
Stability
tendancy of an air parcel to remain in place or change vertical position
increases by cooling the surface
pollution can’t rise in a stable environment
or warming aloft
