Unit 6 Flashcards
Temperature of the Troposphere?
Temperature drops with height
The surface is heat source meaning that the higher you go, the farther from the heat source
Average Tropospheric Lapse Rate
6.5 Celsius per 1 km (3.5 F per 1000 ft)
“Average”- taking all locations at all different times of day to get the temperature
Environmental Lapse Rate (ELR)
actual lapse rate at a given time and place
Radiosonde/Rawinsonde
meteorological instruments are attached to balloons to measure ELR… Radio-gets wind while rawinsonde does not
-Cons: balloon can pop/never make it to the top of troposphere, or wind can move the balloon from place of measurement
Parcel Theory
- explains how we get clouds/rain
- compare environmental lapse rate to that of an air parcel
Air Parcel
theoretical bubble of air; poor conductor of heat
Adiabatic
no exchange of heat
when an air parcel rises…
it is going to EXPAND (as it rises, it expands and must use some energy to grow) & COOL
when an air parcel sinks…
it COMPRESSES, and work is being done by the environment. This causes the temperature to INCREASE
Dry adiabatic Lapse rate (DALR):
This lapse rate will be a constant number; 10 C per 1 km
Saturated Adiabatic Lapse Rate (SALR)
This lapse rate is not a constant number
- <10 C per 1 Km
- Do NOT cool off as quickly as DALR
Latent Heat
heat with a phase change; reason why SALR does not cool off as quickly as DALR
Questions to ask…
- What am I looking at?
- Which is cooling fast? (Environment or air parcel)
- At the given height, will the parcel be warmer or colder?
- Would the parcel be more dense or less dense than the environment?
- Would the parcel rise or sink?
- Is it stable or unstable?
- What is the weather? Stable= blue skies
Stable
parcel is cooling faster; the parcel is colder; dense; sinking
Unstable
environment is cooling faster; the parcel is warmer; less dense; parcel will rise
Conditionally unstable
If parcel is dry- environment is stable; If parcel is saturated- environment is unstable
if the ELR is cooling/heating faster than both the DALR and SALR…
then it is NOT conditional
- ELR>DALR
- ELR
As a parcel rises….
it passes the lifting condensation level and begins to measure through SALR; the water droplets it begins to spit out are the clouds which are built vertically
dew point
is the temperature at which a cloud begins to form or switch from DALR to SALR
Why do clouds stop building as they rise?
stop building once they encounter the tropopause because in the stratosphere temperature begins to rise
when you skink parcel back to surface…
you use DALR and multiply by number of km object will drop. Then you add this temperature to the highest rise point
temperature and height have what type of relationship?
direct; increasing temperature with height in environment
