Conditional Instability
- 5km and above
- note Tp > Te
- A: it will rise on its own since
now it is less dense than the surrounding
environmental air
- The height where Tp
becomes equal to and then larger than Te is
called the level
of free convection
- the parcel is still rising moist
adiabatically (6°C km-1)
- the parcel will continue to rise
until:
- above that point, Tp
< Te , so the parcel will rise no
further
- so, below 4 km where Tp
< Te , the atmosphere is stable to
parcel movement
- above 4 km where Tp
> Te , the atmosphere is unstable
to parcel movement
- this is an example of a conditionally
unstable atmosphere... the condition is
lifting the parcel above 4 km where it can then
rise on its own
It's important to realize that the
current state of the atmosphere can be comprised layers
with different stabilities..... let's look at an example
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