lec 16 Flashcards
does air always rise?
no. it despends on the relationship that the DLR or SLR had to the ELR
when is our atmosphere stable?
if the ELR COOLS slower than the DLR and SLR
this means the air parcels cool faster and naturally wish to fall back to an equilibrium temp
what causes a stable atmos
anything that decreases the ELR (decreasing the rate of still air cooling)
-commonly due to surface cooling activities
-radiative cooling
-advection
or the formation of a temperature inversion
or subsistence
what is the structure of a temp version in our atmos
cold
warm
cold
what is subsistence
the downward movement of warming air which creates in slight inversion layer near the surface, stabilizing the atmosphere
when is the atmos unstable?
when the ELR cools FASTER than both the DLR and SLR. the warm air pocket will keep rising unit the parcel=ELP temp, which could take a while!
when is the atmos conditionally unstable
when the ERL is between then DLR and the SLR. the SLR will cool faster while the DLR will cool slower
what causes atmos instability
-surface heating (convection, creating hot air pockets)
-advection
-cloud radiation cooling (results in —–warmer surface temp
-lifting air, where the warm pocket resides on the bottom
-adding moisture to atmos from the surface
anything that causes the rising air to be warmer and less dense than the air surrounding it. it will rise without a “limit”
what is advection
the movement of warm air over a cool body
could radiation cooling
due to the reflection of the cloud, the upper atmos remains cold while the surface gets warm causes the air to rise rapidly
what is convective instability?
th addition of moisture to the air. common around a water body.
this causes the bottom layer of air to be saturated and rise at SLR and the top layer to rise at eh DLR, commonly forming thunderstorms
using a smoke stack, what does an unstable atmosphere look like
looping
using a smoke stack, what does a stable atmosphere look like
fanning (thin)
using a smoke stack, what does a natural atmosphere look like
coning
when do clouds begin to form in the atmos
when the air parcel hits the LCL and if cloud condensation nuclei are present
LCl incdactes saturation and cooling at SLR